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Authors
Adeleke, K
Albrecht, S
Allison, E
Alva, A
Andersen, N
Andrade, P
Andrews, N
Andrews, P
Arthur, D.K
Atoloye, I
Backman, K
Bai, J
Bair, K
Baker, J
Baker, M
Banks, S
Banuelos, G
Barben, S
Barbour, J
Barnhill, J
Barrios Masias, F
Bartholomew, S
Bary, A
Battany, M
Bauder, T
Bautista, E
Beck, D
Bekkerman, A
Bergsten, S
Bjorneberg, D
Black, B
Blair, T
Blanscet, S
Blaylock, A
Bloedel, D
Bohl Bormann, N.L
Boyd, E
Boydston, R
Bradshaw, D
Bramley, R
Bremer, E
Bronson, K
Bronson, K.F
Brooks, E
Brown, B
Brown, P
Brown, P.H
Bruegman, T
Bruland, G
Bryla, D
Burgess, M
Burke, J.A
Buss, J
Buxton, E
Cahn, M
Callahan, R
Campbell, A
Campbell, C
Campbell, E
Campbell, K
Cappellazzi, S
Cardon, G
Carpenter-Boggs, L
Carr, C
Carroll, A
Carter, P
Chahine, M
Chen, C
Chen, L
Christensen, R
Christenson, R
Christiaens, R
Clark, N
Clay, D
Clough, G
Cobos, D
Cogger, C
Collins, D
Collins, H
Cook, D
Cortus, E.L
Corwin Doesken, K
Costello, R
Creech, E
D'Agati, K
Dabbs, K
Dari, B
Datta, R
Davenport, J
Davenport, J.R
Davis, J
Davis, S
De, M
DeVetter, L
DeVetter, L.W
Deenik, J
Del Moro, S
Delgado, J
Dellavalle, N
Desjardins, M
Donaldson, A
Driver, J.P
Dungan, R.S
Eckhoff, J
Ela, S
Elliott, A
Ellison, E
Ellsworth, J
Engel, R
Englund, R
Engstrom, P
Essah, S.Y
Etesami, M
Evans, C
Evans, S
Ewell, C
Ewing, S
Falen, C
Farnisa, M
Ferguson, R
Fernelius, K
Fife, T
Flint, E.A
Flynn, R
Fransen, S
Frasier, W
Fuhrer, J
Fukuda, S
G. Davis, J
Galdi, G
Gale, B
Gale, J
Gazula, A
Geary, B
Geisseler, D
Gent, D
Getts, T
Ghimire, R
Gibson, R
Girma, K
Gish, J
Gleason, J
Golob, C
Goosey, H
Granastein, D
Granatstein, D
Graybill, D
Greenhalgh, L
Greenwood, M
Greer, K
Griffin-LaHue, D
Griffith, D
Grossl, P
Guldan, S
Gunderson, L
Haas, S
Habteselassie, M
Halvorson, A
Hamasaki, R
Hammac, W
Hammermeister, E
Hansen, N
Harbertson, J
Harrison, J
Harsh, J
Hartz, T
Hatfield, P
Hawks, A
Hayes, P
Heerema, R
Heinrich, A
Hergert, G
Heser, J
Hettiarachchi, G
Hicks, D
Hill, M
Hillmer, R
Hines, S
Hoagland, L
Hoefer, B
Hoheisel, G.A
Holcomb, J
Holden, D
Hole, P
Hopkins, A
Hopkins, B
Hopkins, B.G
Hopkins, T
Horneck, D
Horwath, W
Hosford, P
Housman, M
Howneck, D
Huggins, D
Hunsaker, D
Ippolito, J
Israelsen, C
Iversen, K
Jackson, C
Jackson, G
Janni, K
Jensen, T
Johns, J
Johnson, L
Johnson, R
Johnston, W
Jolley, V
Jones, C
Julian, J
Kabir, Z
Kakkar, A
Karlen, D
Kephart, K
Kerry, R
Khalsa, S
Khalsa, S.S
Khan, Q
Khosla, R
Kilby, M
Kleinman, P.J
Koch, B
Koehn, A
Koenig, R
Kok, H
Kotuby-Amacher, J
Krienke, B
Kruger, K
Larson, M
Lauriault, L
Lazcano, C
LeMonte, J
Lehrsch, G
Leinfelder-Miles, M
Lenssen, A
Lentz, R
Lewis, K.L
Leytem, A
Leytem, A.B
Liang, X
Light, S
Lin, E
Lindemann, W
Lindsey, C
Liptzin, D
Litus, G
Llewellyn, D
Long, D
Long, R
Loo, M
Loomis, G
Love, S
Lowell, K
Lundy, M
Lyons, S.E
Maaz, T
Machado, S
Madsen, I
Madsen, M
Maharjan, B
Manning, K
Marcillac, N
Marcroft, K
Marshall, J
Massey, M
Mathesius, K
Mauch, K
Mazzola, M
McCauley, A
McClellan, A
McClellan, T
McClintick, J
McClintick-Chess, J
McCoy, M
McGrath, J.M
McGuire, A
McIntosh, C
McVay, K
Melton, F
Meyer, R
Mikkelsen, R
Miller, B
Miller, G
Miller, P
Miller, R
Miner, D
Mink, A
Moberg, D
Mohammed, Y
Mon, J
Moody, J
Moore Kucera, J
Moore, A
Mooso, G
Moran Duran, S
Muck, D
Mueller, J
Muhammad, S
Mukhwana, E
Murrell, T
Neibling, H
Neill, K
Nelsen, T
Nelson, T
Neville, B
Nichol, C
Nichols, B
Nkoa Ondoua, R
Noel, B
Norberg, S
Norell, R
Norton, J
Nouwakpo, K
Novak, J
Nunez Moreno, H
Nunez, H
O'Dea, J
O'Geen, T
Ohm, J
Olk, D
Olsen, S
Olson-Rutz, K
Orloff, S
Osmond, D.L
Ouyang, Y
Owens, J
Pace, M
Packham, J
Pan, W
Pandey, A
Pasakdee, S
Pattnaik, R
Paustian, K
Peachey, R.E
Pearce, A.W
Penton, C
Perry, E
Peryea, F
Peterson, C
Peterson, G
Petrie, S
Pettygrove, S
Pierce, F
Pletsch, M
Pollard, A
Pond, A
Pool, K
Popp, B
Porter, G
Pritchett, J
Proctor, C
Pryor, M
Putnam, D
Ramsey, C
Ransom, C
Reddy, K
Reese, C
Reese, M
Reeve, J
Reganold, J
Rey, J
Rick, T
Rieser, C
Riley, B
Rivera, L
Robinson, D
Robison, C
Rogers, C
Ross, A
Rothlisberger, D
Roundy, B
Russell, K
Ruth, M
Saa, S
Sainju, U
Saint Pierre, C
Sanchez, C
Sanchez, C.A
Sanden, B
Satterwhite, M
Savidge, M
Schierer, R
Schott, L
Schott, L.R
Schroeder, K
Seavert, C
Selman, J
Shafer, S
Shao, M
Shapiro, C
Shaver, T
Sheffield, R
Sherman, J
Shiffler, A
Shimabuku, R
Shipp, E
Shiwakoti, S
Shock, C
Sievers, T
Silverstein, K
Slaton, N.A
Smart, D
Smith, J
Smith, R
Smithyman, R
Snyder, C
Snyder, E
Solomon, J
Southard, R
Spargo, J.T
Spokas, K
Stacey, N
Stark, J
Steenwerth, K
Steiner, R
Stephens, S
Sterle, D
Sterubel, J
Stevens, K
Stevens, R
Stewart, C
Stockert, C
Stonaker, F
Storteboom, H
Stott, D
Stougaard, B
Stout, J
Strik, B
Sukor, A
Sullivan, D
Sullivan, T
Summerhays, J
Sunderland, S
Sutton, L
Svedin, J
Tallman, S
Tarkalson, D
Tarkalson, D.D
Tautges, N
Taysom, T
Thorp, K
Thurgood, G
Tiedje, J
Tindall, T
Torrion, J
Trolove, S
Uchida, R
Uehara, G
Ulery, A
Valencia-Gica, R
Van Vleet, S
Vargas, O
Verhoeven, B
Verhoeven, M
Vickery, M
Vigil, M
Walser, R
Walsh, O
Walsh, O.S
Walworth, J
Wang, G
Wann, A
Wardle, E
Waskom, R
Wawrzynski, R
Webb, B
Weeding, J
Weeks, S
Wegner, G
Weiss, M
Weisshaar, E.M
Wenz, J
Wenzel, C
Westcott, M
Westermann, D
Westfall, D
Whitefield, L
Whiting, M
Wickham, A
Wiebe, J
Wieme, R
Wildfong, D
Williams, C
Williams, J
Willmore, C
Wilson, M.L
Winchester, A
Wood, B
Wortmann, C
Wright, S
Yang, R
Yi, Q
Yin, F
Yost, M
Yost, R
Young, S
Youngquist, C
Zabinski, C
Zapata, D
Zemke, P
Zerihun, D
Zhu-Barker, X
Zumbrunnen, J
de Haro Marti, M
jacobson, A
leMonte, J
Topics
Soil Fertility and Soil Health Testing
Manure and Compost Management
Recycled and Repurposed Nutrient Sources
Liming and Soil Acidity
Nutrient Management of Agronomic Crops
Nutrient Management of Horticultural Crops
4R's for N, P, K, S
Environmental and Agricultural Nutrient Management
Sensors and Other Technologies for Nutrient Management
Nutrient Cycling in Regenerative Agriculture
General
Type
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Year
2021
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Filter results282 paper(s) found.

1. Is Cover Crop Species Mixture and Diversity More Important at Building Soil Health than Shoot Biomass in a Semi-arid Region?

Cover crop mixtures (CCMs) as partial fallow replacements have the potential to increase soil health, yet long-term studies on CCMs, especially in semi-arid environments are relatively rare. An eight-year study at two locations in semi-arid Montana sought to evaluate the effect of functional group (N fixer, tap roots, fibrous roots, brassicacae) and species richness (2, 6, and 8 species in a mix) on a range of biological, physical and chemical soil parameters. Although several soil healt... P. Miller, C. Jones, C. Zabinski, K. D'agati, M. Housman, S. Tallman

2. The Elasticity of Biochar Across the Farm: Nutrient Capture, Compost Feedstock, and Soil Amendment

When biomass is thermochemically altered through pyrolysis, what results is biochar, a solid, porous material that is high in carbon (C) (e.g. 80%).  Owing to its unique physicochemical properties, biochar has been evaluated as a soil amendment, a compost feedstock, a means to mitigate nutrient loss and a way to sequester carbon.  Biochar is an appealing material as a farm management tool because its potential use is varied.  As part of a Western SARE grant, soil scientists at ... N. Stacey, D. Collins

3. The Fertilizer Recommendation Support Tool (FRST) Initiative: National Survey on Soil Fertility Recommendations and Correlation/Calibration Database

Soil fertility testing is an integral tool used in nutrient management planning, providing information needed to determine where nutrients are required and how much to apply. While a great deal of effort has been successfully invested in standardizing soil test methods in the U.S. over the last few decades, up-to-date correlation/calibration studies are lacking in many states. In most cases, soil test correlation/calibration efforts lead by land-grant universities are on a state-by-state or l... S.E. Lyons, J.T. Spargo, D.L. Osmond, A.W. Pearce, N.A. Slaton, D.K. Arthur, P.J. Kleinman, J.M. Mcgrath

4. Repurposing Zinc from Mining Tire Waste to a Fertilizer Resource

Zinc (Zn) deficiency is common on high pH soils when growing field crops like Corn, Barley and Wheat.  Not only are crop yields and quality limited by low Zn, but more importantly the dilution of Zn in food stuffs and, thereby, Zn deficiency in the human diet has become a major concern as recognized by the World Health Organization.  At the same time, there is a Global problem in proper repurposing/disposal of used tires that contain between 1-3% ZnO.  In fact, in Chile, t... K. Greer, J. Wiebe, E. Bremer

5. Evaluation of Lime Requirement Estimation Methods for Oregon Agricultural Soils

Soil testing labs in the Pacific Northwest are considering non-hazardous alternatives to the Shoemaker-McLean-Pratt (SMP) buffer method for lime requirement estimation (LRE). While alternative LRE methods have been adopted in other parts of the U.S., they have not been evaluated for Oregon soils.  The goal of this study was to evaluate several LRE methods for agricultural soils from western and eastern Oregon, applying the lime incubation method for actual lime requirement. Twenty-four a... C. Evans, A. Moore, D. Sullivan

6. Factors Influencing Efficacy of Elemental Sulphur Fertilizers

Elemental sulfur is a byproduct of fossil fuel production and produced in large quantities in both the US and Canada.  Fertilizers containing elemental S have a high S content and low manufacturing cost, but may not reliably meet crop requirements for S in the year of application due to the time required for elemental S to be oxidized.  The main factors influencing the oxidation rate of elemental S are particle size, particle dispersion and environmental conditions.  ... E. Bremer

7. Denitrifying Woodchip Bioreactor Performance in the Pacific Northwest

Runoff and tile drainage from agricultural activity is known to be a significant contributor of nitrogen pollution to surface waters.  Denitrifying woodchip bioreactors, also known as Permeable Reactive Barriers (PBR) have been studied as a possible edge-of-field technology for reducing nitrogen concentrations in agricultural runoff.  These units have been studied mostly in the US Midwest and mostly for irrigated crop systems.  Little work has been done in alternative climate r... E.M. Weisshaar

8. Phosphorus and Potassium How Low Can You Go In Alfalfa?

Tissues testing whole alfalfa plants at harvest can more accurately direct nutrient decisions. Developing critical nutrient levels in-season improves recommendations and applications, saving producers time, expense and effort since many growers take samples for hay quality. These three experiments were designed as follows: 1) Phosphorus (P) Rate study with differing rates of P2O5 using monoammonium phosphate (MAP); including: 0, 30, 60, 120, 240 lb P2O5... S. Norberg, S. Fransen, J. Harrison, D. Llewellyn, L. Whitefield

9. Assessing Nutrient Uptake and Accumulation in Oregon Hop Production

Commercial hop production practices and cultivars have changed in the past 25 years and there is a need for updated nutrient management information under cotemporary practices. Current nutrient accumulation curves are only available for nitrogen (N). Current regional nutrient management guides from Oregon State University and Washington State University date back to the 1990’s or earlier. In the meantime, market forces and breeding efforts have led to a proliferation of new varieties, m... A. Moore, D. Gent, B. Verhoeven

10. Twenty Years of Cotton Nitrogen Management and Cycling Trials in the Southwest: What Have We Learned?

Over 20 site-years of nitrogen fertilizer management and cycling trials have been conducted in Lubbock Texas and Maricopa Arizona from 1998 to 2019.  Furrow, overhead sprinkler (OSI), subsurface drip irrigation (SDI) were used.  Soil profile nitrate (0-36 inches in Texas and 0-72 inches in Arizona) was sampled and tested for in all trials.  Nitrogen-15 labeled fertilizer was used for two years in Texas and for two years in Arizona.  Canopy reflectance was measured in every... K.F. Bronson

11. Does Post-harvest Nitrogen Application Affect Blueberry Yield or Cold Hardiness?

In central Washington, nitrogen (N) management in blueberries typically consists of all N being applied prior to harvest.  For early cultivars, such as Duke, this means all fertilizer is applied before the end of June, leaving a long period of growth with no supplemental N.  To evaluate the potential for splitting N fertilizer applications into pre- and post-harvest timings, we conducted an experiment in a randomized complete block design with four replicates on a commercial ‘... J.R. Davenport, G.A. Hoheisel, L.W. Devetter

12. Compost Application in California Tomato Cropping Systems

With the implementation of California Assembly Bill (AB) 341 the availability of composts such as green waste (GW) and co-composted green waste and food waste (FW) as a soil amendment is increasing. The use of those organic amendments in agricultural production systems has been recommended as an effective strategy to make full use of organic waste and improve soil health. However, little information is available to tomato growers to reassess N inputs from using GW and FW. This study was condu... Q. Yi, W. Horwath, S. Haas, X. Zhu-barker

13. Effects of Lime and Micronutrient Amendments for Acidic Soils of the Inland Pacific Northwest

The soil pH of agricultural land in the inland Pacific Northwest has dropped precipitously from native soil levels of near 7.0 pH. Changes that were becoming evident in the 1980’s have reached critical levels, leaving tens of thousands of acres of previous prairie soil at pH under 5.0 and unable to grow an increasing number of aluminum-sensitive crops. Some farmers in the region are beginning to use lime application to neutralize soil acidity. However, pH changes and liming can als... R. Wieme, L. Carpenter-boggs, P. Carter, S. Van vleet

14. Reuse and Reclamation of Phosphogypsum

Phosphogypsum (PG) is a byproduct of phosphate fertilizer production.  It is produced when phosphate rock is treated with sulphuric acid during the manufacture of phosphoric acid, and is composed primarily of  gypsum (CaSO4.2H2O).  It is estimated that over 3 billion tonnes of PG have been accumulated in stacks worldwide and over 150 million tonnes are produced annually.  In North America, PG is stockpiled in stacks that can cover hund... C. Nichol

15. Sugar Beet Lime Effects on High pH Soils and Crops in Northwest U.S.

A viable solution to dispose of sugar beet precipitation calcium carbonate (PCC) is needed due to the unsustainable issues associated with storage. Sugar beet PCC is a lime material produced as a waste product from extracting sugar from sugar beet. The three main sugar beet processing factories in the Amalgamated Sugar Company growing area in Idaho and Oregon have stockpiled approximately 11.3 million Mg of PCC.  Each year these three factories produce a total of 350,000 Mg annually. &nb... D.D. Tarkalson

16. Residue Decomposition of Surface and Incorporated Barley, Corn, and Wheat at Varying Fertilizer-N Rates

Cereal crops are commonly grown in southern Idaho and most parts of the western United States. These cereal crops are routinely harvested for their grain with the remaining plant material (chaff, stems, leaves, etc.) left in the field to decompose prior to planting of following spring crops. Understanding the effects of post-harvest residue management on barley (Hordeum vulgare L.), corn (Zea mays L.), and wheat (Tritcum aestivum L.) residue is important for optimiz... C. Rogers, G. Thurgood, B. Dari, J. Marshall, O.S. Walsh, K. Schroeder, G. Loomis

17. Refining Nitrogen Management for Organic Broccoli Production

Specialty organic fertilizers used in organic vegetable production are expensive. So, from environmental and economic perspectives, growers want to maximize nitrogen (N) fertilizer use efficiency by the crop. This research was conducted to (1) determine sufficient N fertilizer rates for organic broccoli, (2) evaluate the efficacy of a specialty organic fertilizer (feather meal; 12-0-0), and (3) confirm the effectiveness of midseason soil nitrate analyses (0-30 cm) in determining appropriate s... D. Sullivan, R.E. Peachey, A. Donaldson

18. Comparative Analysis of Soil Tests for Soil Health and Nutrient Management

Options for soil tests to address soil health and nutrient management objectives have diversified. We compare different soil test methods to evaluate their similarities for providing recommendations. Traditional soil tests, ion exchange membranes and analyses using the Haney Soil Health Nutrient Tool and Soil Health Index were compared for soil sampled from long-term cropping system trials near Ritzville Washington and from the R.J. Cook Agronomy Farm near Pullman WA. Despite strong... D. Huggins, C. Rieser, J. Reganold

19. Long-term Soil Profile Acidification: Obvious and Hidden Dangers

Soil acidification is occurring in the dryland farming region of the Northwest. Historically, soil acidification in the surface foot has been characterized; however, potential acidification of subsoil is unknown. We examined soil acidification for soil profiles (0 to 5 ft) at the R.J. Cook Agronomy Farm (92 ac) for 17 years following conversion from conventional tillage to continuous No-tillage (NT). Surface soil depths (0-12 in) acidified under continuous NT to below 5. Surprisingly, subsoil... D. Huggins, S. Shiwakoti

20. Evaluating Cover Crops for Nitrogen Management in a Walnut Orchard

Cover crops provide numerous benefits in agricultural systems. From increasing soil water storage to reducing fertilizer inputs, quantifying cover crops benefits is crucial in nutrient management, crop productivity, environmental sustainability, and growers' adoption. The goal of this study was to quantify nitrogen (N) and carbon (C) inputs in a walnut  (Juglans regia L. 'Chandler') orchard that implemented three cover crop mixtures. The study site was a 5-year-old w... D. Zapata, X. Zhu-barker, K. Steenwerth, W. Horwath

21. Estimating Nitrogen Credits from Organic Matter Sources in Orchards

Orchard crops like almonds can effectively utilize different nitrogen (N) sources to meet the high annual N demand for fruit and tree growth. Different fertilizer formulations like urea ammonium nitrate, calcium ammonium nitrate, ammonium sulfate and potassium nitrate are widely and effectively used, and readily available for uptake. Yet, addressing N availability from organic matter sources in orchards, and in turn estimating appropriate N credi... S.S. Khalsa, P.H. Brown

22. Soil Test Interpretation: Saturated Paste, EC, SAR and CEC

Soils of neutral to alkaline pH of the Western United States often contain elevated levels of soluble salts and / or higher concentrations of sodium.  Elevated concentrations of soluble salts limit crop growth and sodium may impact water management.  Competent agricultural management of these soils is dependent on laboratory analysis of: soil soluble salts and there composition and the irrigation water soluble salt constituents.  Soil analysis based on the satura... R. Miller

23. Humic Products in Agriculture: Potential Benefits and Research Challenges

Humic products have been used in cropland agriculture for several decades, but lack of widespread credibility has restricted their use to small proportions of farmers. To improve the credibility of humic products, we propose future actions to close four knowledge gaps. First, while the capacity of humic products to improve plant growth has been proven in greenhouse and growth chambers, more such work is needed in field conditions, especially to determine the modifying effects on hum... D. Olk

24. Winning the Battle Against Environmental Stress by Better Understanding Biostimulant Responses

Biostimulants are increasingly being used by growers to manage environmental stress. Some examples of biostimulants include seaweeds, organic acids, plant based extracts, amino acids, fermentation products, algae, and reprocessed vegetative matter. Holden Research and Consulting (HRC), an independent agricultural research firm in California, has conducted over 500 trials with biostimulants over the last ten years. HRC’s findings indicate that they can be valuable too... D. Holden

25. A Science-based Approach to Trialing Biostimulants and Interpreting Trial Data

Whether you’re reviewing product technical bulletins, or preparing to ramp up your field trial program, this talk will help you avoid common pitfalls in interpreting product data, designing trials, and analyzing trial data. This user-friendlyintroduction will help you put key statistical and scientific principles into practice. Topics to be covered, loosely ordered from simple to more involved: (1) the effects of outliers on mean estimates, (2) the importance of cont... R. Hillmer

26. Overview of the Efficacy of Biostimulants

So-called “biostimulants” have been around a long time, but interest in these crop production products is growing exponentially. A survey of major fertilizer companies indicates it is one of the top three current trends in their businesses— with significant research, development, and investment. However, this major trend in agriculture is fraught with misperception, confusion, and generally lacking credentialed recommendations. Biostimulant is not listed as a ... B. Hopkins

27. Adopting Quinoa in Eastern Idaho – An Investigation of Agronomic Practices

Quinoa production area has been increasing rapidly in eastern Idaho in recent years. However, best management practices for quinoa production are yet to be determined in this area. Field experiments were thus conducted at two locations (e.g., Aberdeen and Tetonia) in eastern Idaho from 2016 to 2018 to evaluated agronomic practices for quinoa production. More successful quinoa production was demonstrated in Tetonia, where air temperature is mostly below 30oC during the summer. In co... X. Liang, R. Yang

28. Nutrient Management in Asian Leafy Vegetables

Asian leafy vegetables are grown intensively in open field and protected agricultural systems. In protected agricultural systems some of the vegetables are grown 6-7 times per year in continuous rotations with a 15-day gap between each rotation. Grown primarily in Fresno, Monterey, Riverside, San Bernardino, Santa Clara, San Luis Obispo, and Ventura counties on around 7026 acres, Asian vegetables are valued at $79 million. In Fresno and Santa Clara counties these crops are grown pri... A. Gazula

29. Evaluating and Revising Guidelines for Blueberry Tissue Nutrient Standards in Washington

Leaf tissue nutrient analysis is frequently used in perennial fruit crops to develop nutrient management plans. In blueberry, samples historically are collected between 15 July - 15 August and the results are used for planning nutrient management the next growing season. Northern highbush blueberry tissue nutrient standards were initially developed by Michigan State University and have recently been revised for western Oregon. However, the proliferation of blueberry p... J. Davenport, L. Devetter

30. Soil Acidification: Identification, Prevention, Adaptation and Restoration

Low soil pH is becoming far more common in Montana soils, with at least 23 counties having at least one field with pH less than 5.5. Soil pH levels in the top 6 inches as low as 3.8 have been measured, resulting in complete crop failure insome locations, yet the problem is highly variable across fields and within soil profiles. Nitrogen fertilizer rates applied above crop nitrogen needs are the largest cause of the acidification. Low soil pH should be verified before managementpract... C. Jones, R. Engel, S. Ewing, P. Miller, K. Olson-rutz

31. Soil Sodicity

Soil sodicity refers to the amount of sodium held on soil cation exchange sites. It is typically expressed either as the percentage of the soil cation exchange capacity filled with sodium ions (exchangeable sodium percentage or ESP), or as a ratio comparing exchangeable sodium to exchangeable calcium plus magnesium (sodium adsorption ratio or SAR). Our primary interest in soil sodium is its impact on soil structure. Sodium, like all soil cations, can flocculate clay particles if present in ad... J. Walworth

32. Managing Soils for CO2 Drawdown: Boon or Boondoggle?

Consensus is growing that meeting the goal of a two degree or less global warming will not only require aggressive greenhouse gas emission reductions across all sectors of the global economy, but also active measures to remove CO2from the atmosphere. Among the broader suite of CO2 removal (CDR) strategies, soil C sink approaches have been deemed as being among the most ready for early deployment and having the greatest net environmental benefits. A variety of exi... K. Paustian

33. Use of Biological Soil Tests to Assess Soil Health and Productivity

Crops require sufficient nitrogen (N) to attain maximum yield potential. The intrinsic N supplying potential of soils is both directly and indirectly related to soil health. Soil health can reliably be predicted with existing soil tests, however, the ability to predict soil N availability, an important proxy for soil health, remains problematic due to a lack of a robust soil tests. As a result, fertilizer recommendations are often made without an accurate assessment of the amount of N th... W. Horwath

34. Soil Diversity and Agricultural Adaptation Across Micronesia

Micronesia, a sub-region of Oceania, comprises approximately 2,100 small islands belonging to five sovereign nations scattered across 2.9 million square miles of the Western Pacific. A majority of the islands are low-lying, sandy coralatolls, but high volcanic islands and raised limestone islands are major population centers in the region. Palau, in the west, was first settled by seafaring peoples as early as 4000-4500 BP and the colonization of Marshall Islands at the eastern ... J. Deenik

35. Wastewater Reuse in the Arid West: Increased Water Supplies and New Paradigms for Nutrient Management

Irrigated agriculture in the western United States is one of the most productive systems in the world. However, in recent years the security of water supplies for agriculture have come into question. Currently states that use Colorado Riverwater are in the process of formalizing drought contingency plans to prevent reservoirs along the Colorado River from going dry. Competition for water with the agricultural sector include both urban and environmental uses. Treated municipal e... C. Williams

36. Biological and Chemical Drivers of Nutrient Dynamics in the Rhizosphere: Applications for Crop Management

The rhizosphere (soil volume around plant roots) is a "hot spot" of plant-microbe- soil interactions, and biological and chemical dynamics in this region play a large role in plant access and uptake of nutrients. Crop plants can influence these dynamics in the rhizosphere to facilitate availability and uptake of nutrients, and can form symbiotic or antagonistic relationships with rhizosphere soil microbes, who either facilitate or compete with plants for nutrient... N. Tautges

37. Paying Attention to Root Traits for the Effective Use of Water and Nutrients

Roots are the main organ for water and nutrient uptake, and more research on root responses to their surrounding environment would help develop novel management strategies to increase agricultural sustainability. Increasing the effective use of resources to reduce environmental impact as we meet the increasing demands for food, fiber and fuel is a priority. Root systems have a key role on this effort. In this session, we will explore how roots respond to abiotic stress, and how root... F. Barrios masias

38. Utilizing the 4Rs to Mitigate Ammonia Toxicity in Roots

The banding of nutrients below the seed row is a common practice in dryland agricultural settings. However, banding below the seed row has been shown to hamper stand establishment and damage seedling root growth in a number of studies. The research presented here uses a novel and inexpensive imaging technique to assess the rate and source management options for reducing root damage when banding N fertilizers below the seed at planting. Survival analysis was conducted ... I. Madsen, W. Pan

39. Belowground Ecological Interactions For Improved Plant Health, Nutrition And Environmental Quality In Agricultural Production

Plant roots are in constant interaction with the myriad of organisms that inhabit the soil. Microbe-root associations are important for a plant’s successful establishment in an environment as they directly or indirectly support nutrient cycling, nutrient uptake and defense from abiotic and biotic stressors. Therefore, managing these interactions offers a great opportunity for improving the efficiency and sustainability of agricultural production by improving plant nutrient upt... C. Lazcano, E. Boyd

40. Improving Nutrient Use Efficiency in Irrigated Areas of Western Agriculture

Much of Western US crop production requires irrigation for optimum performance. Irrigated cropping systems often include high-value crops grown with intensive nutrient management. Irrigation management is integral with nutrient management, especially for nitrogen. The predominant form of plant-available nitrogen in soils is nitrate, which is highly mobile and greatly affected by irrigation management. Irrigation, therefore, adds complexity to already intensive management and introduces c... A. Blaylock

41. Nutrient Management and Improved Efficiency of Drip Irrigated Processing Potatoes

Water availability may be the single greatest limiting factor for potato production in irrigated areas of the PNW and other parts of the world. Arid climates with warm temperatures during the day and cooler, drier nights produce some of the world’s largest potato yields with some the best processing quality. However this comes with a challenge and that is water use efficiency. While for many years there is an abundance or adequate water it will not always be the case. These concern... G. Mooso

42. Irrigated Cereal Response to Nitrogen Applications to Improve Efficiencies for Yield and Protein

High yielding and quality barley (hordeum vulgare L.) is critical for producing malt. Research trials investigating the impact of final irrigation timing cutoffs [i.e., late boot, soft dough, and soft dough + 7 days (SD7)] and nitrogen (N) rates (0 to 150 lb N/ac) at the Kimberly Research and Extension were conducted during the 2015 growing season. Our study measured yield and quality factors as well as N uptake and partitioning. Cutoff of irrigation at the boot stage severely stressed p... C. Rogers, B. Dari, H. Neibling

43. Phosphorus Efficiencies of Liquid P Fertilizers as Evidenced by P Adsorption Isotherms of Western Calcareous Soils

The high levels of free lime or calcium carbonate (CaCO3) in arid Western U.S.A. soils reacts with phosphorus (P) fertilizers to form Ca-P minerals that are not available to plants through P fixation. Enhanced efficiency P fertilizers may potential decrease P fixation. The objective of this study was to identify P fixations levels associated with several enhanced efficiency P fertilizers on a basic soil (pH 8.03) over a 1-, 3-, and 7-day time period, and to use that data to adjust P fertilize... J. Williams, S. Davis, K. Dabbs

44. Approaches to Nutrient Recommendations

Scientific based crop nitrogen (N) fertilizer recommendations are vital to guide N management within the agricultural sector. Accurate recommendations can maximize producer economic returns and minimize losses to the environment. Obtaining accurate recommendations is a dynamic process that requires constant research to update recommendations (within current scientific knowledge) and to better understand soil N cycle processes (develop new scientific knowledge) that can further ... D. Tarkalson

45. Effect of Management on Nitrogen Budgets and Implications for Air, Soil, and Water Quality

Nitrogen is a key nutrient for both national and global food security, and nitrogen inputs from organic and/or inorganic sources are essential to maintain sustainable and economically viable agricultural systems. The challenge with nitrogen is that it is very dynamic and mobile, and some forms are subject to biogeochemical transformations that contribute to atmospheric, surface and leaching losses. Although nitrogen provides important rural, national and global economic benefits, nitrogen los... J. Delgado

46. Nutrient Management in a Regulated Environment

Laws and regulations mandate nutrient management that good managers have long practiced or should have. Prior to governmental regulations, economics was a major regulator. However, high returns on nitrogen inputs led to over application, causing environmental issues and human health concerns, which led to legal regulation. The Federal Clean Water Act (CWA) and the California Porter-Cologne Act provide for regulation of pollution of surface waters, groundwaters, and wetlands. The statewide Wat... N. Dellavalle

47. Soil Water and Plant Canopy Sensor Technologies to Optimize Water and Nutrient Use

In many respects, agricultural technology is doing things now that were only imagined 20 to 30 years ago. Yet, grower tools that provide information and actionable knowledge on water and nutrient availability still remain a challenge. Clearly, rapid development of data transfer and processing platforms to date has provided rich maps of grower fields with overlays of location-specific information but their utility is still limited by our ability to accurately measure the parameters that are th... C. Campbell, N. Hansen, B. Hopkins, S. Evans, E. Campbell, A. Campbell, L. Rivera, D. Cobos

48. Interagency Cooperation to Improve Nitrogen Management for Water Quality Protection

Agriculture and water are inseparable in a semiarid region such as Colorado. Adequate clean water supplies for drinking, agriculture, industry, and recreation are critical for the lifestyle Coloradans enjoy. The Agricultural Chemicals and Groundwater Protection Program (ACGPP) was created by the Colorado legislature in 1990. The purpose of this unique program is to reduce the potential impairment of groundwater by agricultural chemicals have on groundwater and the environment by preventing gr... T. Bauder, E. Wardle, R. Wawrzynski, K. Mauch

49. Nitrogen and Water Interactions: Crop Production Systems Case Studies

Farmers and urban land managers have to strike a tenuous balance between achieving plant growth goals while responsibly managing natural resources. Water quality and scarcity issues are prominent concerns, along with soil quality preservation and conservation of fuel and fertilizer resources. The purpose of this presentation will be to highlight case studies where water and crop management practices were considered together to improve the efficiency of resource use. Evidences of water scarcit... B. Hopkins, N. Hansen

50. Groundwater Protection in California: Nitrogen Planning and Reporting

Concern over the environmental consequences of nitrogen released into the environment from agricultural operations goes back at least to the 1970s. Through the federal Clean Water Act (1972) and various state laws dating to that same time period, government has had the power to regulate nitrogen use for decades. However, only in recent years have serious attempts to restrict agricultural N usage become widespread. In California several Regional Water Quality Control Boards have recently ... D. Muck, T. Hartz

51. Estimating Non-Fertilizer Nitrogen Contributions

California growers are facing increasing pressure to reduce nitrogen (N) losses in crop production. However, growers also need to maintain high yield levels to remain competitive. This is only possible when N inputs from all sources can be quantified and fertilizer application rates can be adjusted accordingly. The major sources of non-fertilizer N include soil residual nitrate, nitrate in the irrigation water and N mineralized during the growing season from organic material, such as soil org... D. Geisseler

52. Irrigation Effects on N Availability

Irrigation is necessary for crop production in the western US where the climate ranges from Mediterranean to desert conditions. Management of irrigation can potentially have large effects on crop available N because nitrate-N readily moves with water and because soil moisture affects root activity and the uptake of N. Additionally, fertigation is commonly used to supply N to crops though the irrigation system. More efficient use of N can be achieved by assuring that an irrigation system has a... M. Cahn

53. Nitrogen Budgeting for Tree Crops

In recent years, nitrogen (N) budgets and the 4 R’s approach (right rate, right time, right placement and right source) to N fertilizer management has been gaining more acceptance. In the N budget and 4 R’s approach, fertilizers are applied in proportion to demand and timed with periods of N uptake. As a result, demand is satisfied in a timely fashion avoiding the application in excess of uptake capacity. While N is required for all plant processes, it is the specific growth and d... S. Khalsa, S. Muhammad, P. Brown

54. Nitrous Oxide Emissions: Assessment and Mitigation in Irrigated Cotton in the Western USA

Nitrogen from fertilizers is a major source of the potent greenhouse gas nitrous oxide (N2O) in irrigated cropping systems. To date, N2O emission data is scarce for row crops in the Western USA, especially, the desert southwest, where seasonal irrigation quantities can exceed 40 inches. The objective of these studies was to assess the effect of N fertilizer management on N2O emissions from furrow-, overhead sprinkler-, and subsurface drip-irrigated (SDI) cotton (Gossypium hirsutum L.) in... K. Bronson, D. Hunsaker, K. Thorp, C. Williams

55. Crop Genetic Variability for Nutrient Use Efficiency: Biological Foundation, and Case of Spring Wheat

Recent advances in plant molecular biology have elucidated the mechanisms by which plant species adapt to low-nitrogen and low-phosphorus environments. This has paved the way to new perspectives and strategies for breeding and genetic engineering: the design of low-nitrogen and low-phosphorus cultivars in order to optimize nutrients use efficiency and enhance economic and environmental sustainability. In this paper, we review the enzymatic activity of root hair-embedded transmembrane proteins... R. Nkoa ondoua, M. Etesami

56. Science and Stakeholder Engagement on 4R Nutrient Stewardship, Sustainability and Nutrient Performance Indicators: a Recent Central to Eastern U.S. and Global Perspective

Farmers and society are becoming more aware of the need to better protect water, air and soil resources. The focus of the International Plant Nutrition Institute (IPNI) is on responsible nutrient management and stewardship to support the needs of the growing human family. Since 2007, IPNI has been more actively engaged with university scientists, federal and state agencies, agribusiness associations, crop advisers, and nongovernmental partners to get more of the applied nutrients - especially... C. Snyder

57. Canola Roots of Water and Nitrogen Use Efficiency: New Lessons for PNW Wheat Growers

The semi-arid inland Pacific Northwest (iPNW) has primarily produced wheat for 125 years due to favorable climate, soils, economics and policy drivers. Shifting drivers over the past decade related to energy, climate change, regional and global markets have created new opportunities for the integration of canola into iPNW wheat-dominated rotations. Traditional wheat grower mindsets required an agronomic reboot, forged by an understanding of canola vs. wheat physio morphology, an explosion of ... W. Pan, T. Maaz, I. Madsen, W. Hammac, M. Reese

58. Nutrient Lessons from Long-term Cropping System Studies

The long-term efficiency of applied nutrients in agricultural soils depends not only on the efficiency of use by the immediate crop, but also on the efficiency of use for residual forms. However, determining this efficiency is difficult due to the slow turnover of residual forms, large soil nutrient reserves, and multiple processes controlling the fate and crop utilization of nutrients. Long-term cropping system studies are useful in this regard because they allow small changes to accumulate ... E. Bremer

59. Fine Tuning Nitrogen Management Soil Tests

Recent changes in environmental regulations have brought a renewed focus on residual soil nitrogen. Years ago when much of the N was broadcast or injected into cultivated fields there were relatively simple techniques to make reasonable estimates. In more recent times drip irrigation, fertilization, and non-till have complicated the techniques required to measure residual N. This is especially the case in deep rooted crops. This presentation will discuss using quantitative soil test... K. Backman

60. Nebraska Nitrogen Management Present and Future

University of Nebraska faculty have been refining their N rate recommendation procedure since the 1970s. At that time, they introduced a procedure for predicting soil nitrate-N availability and effect on subsequent corn N needs. In the 1990’s this procedure was refined based on 81 state wide N rate experiments. In 2003-2006 it was re-confirmed with 32 state wide irrigated corn trials. The current algorithm is the following: N need (lb/ac) = [35 + (1.2 x EY) - (8 x NO3- N ppm) - (0.14 x ... C. Shapiro, R. Ferguson, C. Wortmann, T. Shaver, B. Krienke, G. Hergert, B. Maharjan

61. Test Driving a New Nrcs Nutrient Budget Calculator for Nutrient Management Planning in California

In executing its mission to aid landowners in making conservation improvements, the USDA-Natural Resources Conservation Service (NRCS) assists landowners in identifying their operation’s potential risks to natural resources, if any. For assessing a cropland producer’s nutrient management, determining whether their nutrient applications rates might be considered excessive or has a potential to load up soil levels is key. However, NRCS does not make prescriptive ... B. Gale, Z. Kabir

62. N Management Tools for Desert Vegetables

Over the past two decades studies have been conducted to evaluate diagnostic tools and practices aimed at the development of more efficient N management in desert vegetable cropping systems. In all cases initial studies were conducted in small plots at University Research Farms. However, practices that were found to be promising were scaled up into large experiment-demonstration in commercial production fields. Studies show that while tissue tests were often reasonable diagnostic tools for N ... C. Sanchez

63. Application of Ion Exchange Resin Membranes to Nitrate Testing in the West

Resin membranes have been used since the 1960s to measure P supply from the soil. In the 1990’s the Plant Root Simulator (PRS®) probe was invented to further refine a method to measure N mineralization from soil organic matter. The functional measurement of soil N supply during incubation has been applied to both in situ measures and in lab research studies. Extending the PRS® measurements of N ‘intensity’ or flux to a meaningful number that a plant can utilize was a... K. Greer, E. Bremer, T. Sievers

64. Evaluation of Soil Tests for Potentially Mineralizable Soil Nitrogen in Snake River Plain Soils in Idaho

Soil testing is a critical component of fertilizer management strategies for ensuring optimal nutrient applications for agricultural crop production while minimizing potentially negative environmental impacts due to excess fertilizer applications. Research to determine accurate soil test methodologies dates back over 150 y; however, a rapid soil test for the determination of potentially mineralizable nitrogen (N) that consistently provides reliable results has alluded researchers. A recent re... C. Rogers

65. Measuring Ammonia Loss Using Field-scale and Laboratory Techniques

Following the surface application of urea to soil, there is the potential for nitrogen (N) loss from ammonia (NH3) volatilization until sufficient rain or irrigation has moved it into the soil. Many studies measuring NH3 loss have used laboratory and microplot field studies. The limitation of these techniques is that they do not represent NH3 loss under natural conditions because enclosures alter air movement, humidity, and soil and air temperature inside the chambers. However, they... A. Heinrich, D. Sullivan

66. Sustaining Agriculture and the Environment Through Healthy Soils

Soil health can be defined as the continued capacity of soil to function as a vital living ecosystems that sustains plants, animals, and humans. Land management practices that enhance soil health offer many opportunities to respond effectively to current challenges to agricultural sustainability and environmental quality. Practices such as cover crops and no-till can enrich mineral soils with organic carbon, enhance water infiltration, and increase the available water holding c... S. Shafer

67. Evolution and Utilization of the Smaf for Soil Health Assessments

Soil degradation remains a global problem caused by many diverse factors. In response to this global need, farmers, ranchers, soil scientists, ecologists and many other groups interested in protecting, restoring, and/or enhancing our soil resources have recently begun to embrace the concept of soil health to achieve those goals. This presentation will focus on three critical points: (1) the modern concept of soil health did not spring up overnight, (2) critical milestones regarding soil quali... D. Karlen

68. Soil Management Assessment Framework Use for Identifying Soil Quality Changes in Irrigated Agriculture

The 820 km2 Twin Falls (Idaho) irrigation tract is part of the Natural Resources Conservation Service (NRCS) - Conservation Effects Assessment Project (CEAP). Furrow irrigation was initiated in the early 1900s but, since the 1990s, the NRCS Environmental Quality Incentives Program (EQIP) and other specialty projects have resulted in conversion of approximately 40% of the irrigation tract area to sprinkler irrigation. Most past CEAP research has focused on water quantity and quality, effe... J. Ippolito, D. Bjorneberg, D. Stott, D. Karlen

69. Soil Biological Indicators of Soil Health for Soil Health Assessments

Soil is one of our nation's most valuable resources that provides life-sustaining functions. Billions of organisms live belowground and perform critical soil processes to support plant, animal, and human health aboveground. By shifting our view of soils from an inert growing material to a biologically diverse and active ecosystem, we can help create more sustainable farms, ranches, and forests to provide the food and fiber for our rapidly growing population while protecting land, air and ... J. Moore kucera

70. The Performance of the Soil Health Tool in Irrigated Calcareous Soils of the Western U.S.

The Soil Health Tool (SHT), utilizes an integrated approach to soil testing for quantification of soil health and estimation of available nutrients for crop growth. The SHT is designed to mimic nature’s approach, as closely as possible, in order to estimate soil nutrient availability in the laboratory. The test itself includes extraction with water to measure soluble nutrients (C, N, P), a soil microbiological measurement, and a weak organic acid extraction to mimic additional nutr... A. Leytem, A. Moore

71. Preliminary Assessment of the Solvita-CO2 Test in Characterizing Management Effects on Soil Biological Activity in Some Soils of Hawaii

The health of agricultural soils depends to a great degree on management practices that promote soil organic matter accumulation. While total soil organic carbon (C) is the standard measure of soil organic matter, it changes slowly and does not provide a sensitive enough test to assess short term management effects on soil health. However, a key indicator of healthy soil is potential biological activity, which can be measured rapidly with soil testing via short-term carbon (C) mineralization ... J. Deenik, M. Loo

72. Improving Nitrogen Use Efficiency of Cool Season Vegetable Production Systems with Broccoli Rotations

Nitrate leaching in leafy vegetable production in the Salinas Valley, CA is a continuing problem. Increased levels of nitrate in groundwater resources affects the ability of municipalities to access drinking water that meet federal water quality standards. Regulations by the Central Coast Regional Water Quality Control Board are now requiring growers to improve nitrogen use efficiency (NUE) in production fields. In prior studies we found that above ground biomass nitrogen (N) at crop maturity... R. Smith, M. Cahn, T. Hartz

73. Digital Tools to Improve Sustainable Agriculture Practices

Visualizations have been shown to promote learning and understanding and to aid in analysis and problem solving. Many concepts in agriculture are well suited to demonstrations that are used in classroom settings or part of training events. However, many demonstrations are difficult to seed in a large setting, or take more time than can be allotted. A series of demonstrations were either filmed or created in animation to provide a digital means by which trainers could more easily train their s... R. Flynn, J. Walworth, J. Davenport, A. Ulery, D. Bloedel, J. Gleason

74. Can the “Diviner” Probe Help Explain Water Use by Field Crops?

Farms in New Mexico rely on various methods of irrigation but primarily flood or sprinkler systems. Timing irrigations to meet crop water needs using regulated ditch systems is not based on the actual need of the crops. However, pressurized systems that utilize groundwater have the ability to be adjusted to deliver variable amounts of water. A survey of irrigation practices was done in the Pecos River Valley by installing tubes in fields of pecan, alfalfa, corn, chile, and cotton and scanning... R. Flynn

75. Do 1:1 Soil Extracts for Salinity Underestimate Leaching Fractions?

Soil test laboratories often include 1:1 pH and salinity measures as part of their routine analysis. The saturated paste method is also a choice but may not be selected due to a higher cost associated with the procedure. Historical crop response to salinity has been largely carried out using the saturated paste extract procedure. Plant response estimates to salinity are based on the saturated paste method. Leaching fractions are determined from the saturated paste extract as well. Recommendat... R. Flynn, A. Ulery

76. Amending Acidic Soils for Sustainable Wheat Production

Soils in the Inland Pacific Northwest region have been gradually declining in quality as the result of applications of nitrogen fertilizers, regardless of the nitrogen form. Soil test reports evaluated in the 1980’s and 90’s indicated this decline. Recent surveys have provided more extensive data that the pH decline is continuing. Soil test reports indicate that nearly 90% of soils have declined to below 5.2 pH (strong to very strongly acid) in the surface layer of the soil profil... P. Carter, G. Wegner

77. Cover Crops for Hop Production in Semi-arid Climates

Tilling interrows to control weeds is a common practice in hop production, especially in the Yakima Valley of Washington which receives 8 inches average annual precipitation and produces 74% of US hops. Dry, tilled interrows leaves topsoil prone to erosion and decreases soil organic matter over time. The goal of this three-year study is to determine cover crop species that would be profitable weed control alternatives to tillage for hop producers in semi-arid climates by providing ground cove... S. Del moro, J. Davenport, C. Jones

78. Effects of a One-time Compost Addition on Soil Health in a Rainfed Dryland Organic Wheat System

Maintaining adequate soil fertility and health is a challenge in dryland organic wheat systems. This research examines the short-term impact of a one-time addition of compost on the soil health in a rainfed dryland organic winter-wheat (Triticum aestivum L.) fallow system. Field plot experiments were established in 2015 in a semiarid dryland organic wheat field in Snowville, Utah with the following treatments: control (C), compost at 12.5 Mg/ha dry weight (CM1), 25 Mg/ha (CM2), 50 M... I. Atoloye, J. Reeve, A. Jacobson, E. Creech

79. Nitrogen Mineralization of Dairy Manure in a Calcareous Soil Under Field Conditions

Understanding N transformations in fields receiving dairy manure applications is an important component of managing this nutrient source to maximize crop profitability and reduce environmental damage. The objective of this study was to determine the net N mineralization from field applied dairy cow manure to a Portneuf silt loam as affected by application rate, application frequency, and naturally fluctuating temperatures throughout the growing season. This study was conducted in a field loca... D. Graybill

80. Nitrogen Availability and Use Efficiency in Corn Treated with Contrasting Nitrogen Sources

Nitrogen (N) is required in relatively large quantities for corn production and is often the limiting nutrient for growth and high yield. Improved understanding of N cycling in agroecosystems is essential for increasing N use efficiency (NUE) and sustainable food production. The transformations between organic N and inorganic N form a central part of the internal soil N cycle. Utah farmers grow approximately 990,000 tons of silage corn annually, which provides important forage in livestock an... A. Kakkar, J. Norton, Y. Ouyang

81. Accumulation and Partitioning of Nutrients by Irrigated Sugar Beets During the Growing Season in Southern Idaho

Amounts and rates of dry matter and nutrients for irrigated sugar beets (Beta vulgaris L.) during growing season have received limited attention. A study was conducted during the 2014, to evaluate amounts, rates, and partitioning dynamics of dry matter, macro- (N, P, K, Ca, Mg, S, and NA), and micro- (Fe, Mn, Zn, Cu, and B) nutrients accumulated by sugar beet in different growth stages under minimum-stress field environment on an irrigated Portneug silt loam soils of southern idaho. Urea, mon... M. De, A. Moore, R. Mikkelsen

82. Creating Prescription Variable Rate Irrigation and Fertilization Zones: Water and Nutrient Management Interactions

Variable rate irrigation (VRI) and variable rate fertilization (VRF) technologies allow irrigation and fertilization rates to be spatially customized. VRF is widely adopted, but VRI is an emerging technology with minimal adoption. As water is often the driving force in nutrient cycling, our overall objectives are to evaluate VRI influences on VRF and vice versa; and to combine these technologies to significantly increase crop yield and quality, conserve water, and minimize environmental impac... J. Svedin, N. Hansen, R. Kerry, R. Christensen, B. Hopkins

83. Improving Phosphorus Use Efficiency: Right Rate, Timing, and Placement and Enhanced Efficiency Fertilizer Sources: Research Summary

Phosphorus (P) fertilization is essential for societal sustainability. However, plant P uptake is inefficient due to poor soil P solubility, especially for crops such as potato (Solanum tuberosum L.) plant due to relatively poor rooting efficiency and high demand. Phosphorus use efficiency (PUE) improves with the right rate, timing, placement, and with using enhanced efficiency fertilizer products (EEF). We have conducted several dozen studies over nearly two decades showing PUE is impro... E. Shipp, T. Hopkins, B. Hopkins

84. Nitrogen and Irrigation Water Interactions in Drought Stressed Kentucky Bluegrass

There is increasing pressure in arid regions to conserve water, especially during drought. Turfgrass is the irrigated crop of greatest acreage in the United States and water use for irrigating turf is coming under scrutiny in urban ecosystems. The purpose of this study was to evaluate water use and growth of Kentucky bluegrass (Poa pratensis L.) under various irrigation and nitrogen (N) regimes. A study was conducted in an environmentally controlled growth chamber with established Kentuc... K. Russell, A. Hopkins, N. Hansen, B. Hopkins

85. Polymer Coated Urea: Meeting Plant Needs While Mitigating Environmental Impacts — Research Summary

Fertile soil is the foundation of food production and is maintained by replacing nutrients lost in harvest or to the atmosphere and hydrosphere. Nitrogen (N) accounts for approximately half of global fertilizer inputs. However, N recovery by plants is inherently inefficient due to “leaks” in the system, causing air and water pollution. Additionally, poor fertilizer efficiency is a waste of natural resources and potentially reduces yields, crop quality, and grower profits. Nitrogen... S. Bartholomew, T. Hopkins, B. Hopkins

86. Effect of Cover Crops and Compost on Soil Water Availability in Organic Dryland Wheat

In low input semi-arid regions, water is the major limiting factor in crop production. Cover crop biomass and compost are good source of organic matter, that improve biological activity and water holding capacity of soils. However, dryland organic wheat growers rarely apply soil amendments due to cost and cover crops can lead to the depletion of soil water which decreases the yield of subsequent winter wheat. This study investigates the potential for a synergy between compost addition and cov... K. Adeleke, J. Reeve, E. Creech, I. Atoloye

87. Nitrogen Management and Water Productivity of Grain Crops Under Drought or Limited Irrigation

The interactions of nitrogen management and water have been the subject of many studies that have improved crop management practices. Water scarcity however, has become a pressing contemporary challenge for agricultural and food sustainability, especially in many arid and semi-arid regions of the world. As the amount of available water for irrigation decreases, more studies must shift their focus to how nitrogen fertilizers influences water use efficiency. Numerous strategies are currently em... S. Evans, N. Hansen, A. Blaylock

88. Developing a Soil Test Kit for Extension Programming

Soil and horticulture Extension programs are enhanced by hands-on and interactive activities. Readily available and inexpensive soil test kits can be useful in Extension programming in the classroom and the field. With the addition of a few extra supplies and tools, a complete kit can be created for Extension educators to use in horticulture and soil management programming. Five soil test kits from different manufactures were evaluated for both ease of use and accuracy. All kits inc... C. Youngquist, J. Norton, J. Harsh

89. Precision Sensing for Improved Wheat Production

Improving nitrogen (N) use efficiency (NUE) from current 35-40% is important for growers’ sustainability and environmental quality. Unmanned Aerial Vehicles (UAVs) are proposed as an alternative to traditional field scouting for making crop management decisions. Precision sensors and cameras mounted on the UAVs provide high quality images which can be used to make fertilizer recommendations in-season based on crop nutrient status. A study was conducted at 5 locations in Southern Idaho i... O. Walsh, J. Marshall, J. Mcclintick-chess, S. Blanscet, C. Jackson

90. Plant Available Silicon Application in Winter Wheat

Many studies throughout the world has shown that various crops have positively responded to silicon (Si) application in terms of plant health, nutrient uptake, yield, and quality. The study’ objective was to evaluate the effect of Si application rate and time on winter wheat growth and development, grain yield and grain quality. Results suggest that application of plant available silicon at 50% rate at either emergence or Feekes 5 appears to be more advantageous in terms of winter wheat... O. Walsh, J. Mcclintick-chess, S. Blanscet

91. Response of Spring Wheat to Varied Nitrogen and Water Applications

This study’s objectives were to 1) determine the minimum N and water requirements for optimum wheat grain yield and quality; 2) develop a sensor- based system for identifying – and distinguishing between – N and water stress; 3) produce grower recommendations based on the developed model; and 4) improve grower adoption of efficient water and N application practices and enhance grower understanding of sensor-based technologies. This was the first year of the study, project wi... O. Walsh, J. Torrion, X. Liang, J. Mcclintick, S. Blanscet

92. Making N Budgets Work: a CCA View from the Field

Nitrogen budgets are the object of more research and discussion these days. Much more is known about crop N requirements than was available just a few years ago. The problem in the field is that the amount of nitrogen needed to produce the crop may need to be changed significantly depending on field, crop, and weather conditions. The Certified Crop Adviser (CCA) in the fields needs to take the basic nitrogen information and adapt it into a nutrient program designed for each specific field.... K. Backman

93. Drought and Nitrogen Stress Effects on Maize Canopy Temperature

Water scarcity is a major threat to the sustainability of irrigated agriculture. Management practices, such as limited irrigation, that seek to maximize the productivity of a limited water supply are critical. Remote sensing of crop canopy temperature is a useful tool for assessing crop water status and for more precise irrigation management. However, there is potential that nutrient deficiencies could compound the interpretation of water status from leaf temperature by altering leaf color an... A. Carroll, C. Lindsey, J. Baker, B. Hopkins, N. Hansen

94. Phosphorus and Organic Acid Bonding Impacts at Varying Soil pH

Phosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past six years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) mostly in calcareous, low OM soil. Studies comparing CBP to ammonium polyphosphate (APP) and monoammonium phosphate (MAP) applied to soil show season-long increases in... T. Blair, C. Ransom, P. Hosford, J. Svedin, L. Sutton, A. Winchester, K. Manning, T. Hopkins, B. Hopkins

95. Understanding Crop Response to Micronutrients

There are many factors that affect crop response to micronutrients, and response to micronutrients is often less predictable than response to N, P, and K. Responses to micronutrients may be dramatic if the nutrient is deficient, but more often, responses are incremental yield increases or even only maturity or quality improvements. Micronutrient chemistry in the soil is complex and there are numerous interactions with other nutrients and environmental conditions. While predictability of micro... A. Blaylock

96. Nitrogen Management and Budgets for Irrigated Cotton in the Western USA

We present research on new and improved and updated N fertilizer management recommendations for 4-bale/acre cotton based on a 36-inch NO3-N soil test for irrigated cotton from a 2-year study on surface/furrow irrigation study and a 1-year study under sprinkler irrigation. We also compared UAN with UAN plus the N loss inhibitor Agrotain Plus. Additionally, we compared reflectance- based N fertilizer management with soil test-based management. Nitrogen balances indicated that residual soil NO3&... K. Bronson, J. Mon, E. Bautista, D. Hunsaker

97. Minimizing Nitrogen Inputs While Optimizing Verdure and Growth of Kentucky Bluegrass with Polymer Coated Urea

Nitrogen (N) fertilizer increases turfgrass verdure but also increases maintenance costs due primary to mowing. A two-year fertilization study was initiated April 2014 at two established Kentucky bluegrass sites with sand and loamy sand constructed field soils in Provo, UT. A grower’s standard practice (GSP) of urea split applied monthly was compared to blend of uncoated and polymer coated urea (PCU). The PCU was applied in 1, 2, or 3 split applications. The dual application applied at ... J. Buss, J. Gish, B. Hopkins

98. Cropmanage: an Online Decision Support Tool for Irrigation and Nutrient Management

Vegetable and berry growers on the central coast of California are under growing regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of these crops are the soil nitrate quick test (SNQT) for monitoring soil residual N concentrations and evapotranspiration (ET)-based irrigation scheduling for estimating crop water requirements. We developed a web-based software application, called CropManage (http... M. Cahn, T. Hartz, R. Smith, B. Noel, L. Johnson, F. Melton

99. Stratified Soil pH Identification Project

Columbia County Washington is in the foothills of the Blue Mountain Range and the edge of the Palouse wheat country. The soils of the farming region are mostly a rich silt loam having a rainfall ranging from 12 inches to 25 inches north to south respectively with elevations from 1000 to 3200 feet. About 90% of the cropping systems have adopted conservation tillage, direct seeding or no-till, which has been good for the management of soil erosion. In April 2006, intense soil sampling (1 cm inc... P. Carter, T. Bruegman

100. Siderophores to Increase Iron Availability

Siderophores are biologically produced low molecular weight amino acids that act to chelate metals. These can be generated by soil microorganisms and some plants, most notably grasses, also produce siderophores. These compounds are associated with improved availability of iron in the soil. This manuscript presents a survey of microbial siderophores present in soils under chlorotic and non- chlorotic ‘Concord’ grapevines. ... J. Davenport, A. Pollard, T. Sullivan

101. Ammonia Volatilization from Urea Vs. Alternative Nitrogen Fertilizers

Substantial ammonia (NH3) volatilization can occur from surface application of urea on sandy soils with low pH buffering capacity such as those in the semi-arid Columbia Basin. Previous studies have reported loss of up to 60% of urea-N as ammonia on these soils. The objective of this study was to quantify ammonia loss per acre for urea and for alternative N fertilizer products, including: sulfur-coated urea (SCU), urea coated with NBPT urease inhibitor (urea + Agrotain), ammonium su... S. Del moro, D. Sullivan, D. Horneck

102. Response of Mesa Russet Potato to Potassium Fertilizer Source and Time of Application

Research studies have shown that the source of potassium (K) fertilizer can influence potato tuber yield and quality. Most of the K fertilizer studies conducted have focused on muriate of potash (MOP) and sulfate of potash (SOP). Potassium Acetate (Bio-K) has been introduced as a new source of K fertilizer. Field studies were conducted at the San Luis Valley Research Center, Colorado State University, to evaluate the yield and quality response of potato cultivar Mesa Russet to source and time... S.Y. Essah

103. Identifying Saline and Sodic Soils

Soil salinity can become a sever limitation to crop yields and soil quality. Routine evaluation of salinity often involves a 1:1 extract of water to soil. However, salinity tolerance has been defined from saturated paste extracts, not 1:1. Saturated extracts take more time to determine in the lab but is the best method to ascertain crop susceptibility to yield loss. Mathematical conversions from 1:1 to saturated paste are possible to do but may not translate across regions. In a similar way, ... R. Flynn

104. Pecan Response to Foliar Nickel Applications

New Mexico’s pecan industry is one of the state’s most important agricultural assets. In 2010, pecan growers in Dona Ana County produced 19,504 kg of pecans, on over 10,000 ha and was worth over $123 million dollars, making Dona Ana county the number one pecan producing county in the nation. Nickel (Ni) is a component of the enzyme urease which is critical for the mobilization of nitrogen within the pecan tree. Deficiency symptoms are often expressed in pecan as a “mouse-ear... R. Flynn, R. Heerema, S. Moran duran

105. Moving Toward Sustainable Cropping and Grazing Systems

During the 1980’s Burleigh County, North Dakota farmers and ranchers historically managed their operations in a traditional manner of tillage dependent cropping systems with simplified rotations, no cover crops, high input costs, and season long grazing. In the early 1990s, the Burleigh County Soil Conservation District Supervisors formed a team and began implementing no-till cropping systems with some crop diversification and simple cover crop mixtures. Native Rangeland was established... J. Fuhrer

106. Manganese Nutrition and Photosynthesis of ‘Pawnee’ Pecan

Southwestern pecan (Carya illinoinensis) orchard soils are alkaline and calcareous which negatively affects manganese (Mn) availability for root uptake. Mn is essential for photosynthesis because of its roles in the photosystem II complex and chlorophyll biosynthesis. Levels of leaf Mn for optimum photosynthesis (Pn) in pecan is not known. Our objective was to characterize the relationship of widely different leaf tissue Mn concentrations on Pn. The experiment was conducted from 2011 through ... R. Heerema, J. Sherman

107. Nitrogen Cycling and Fertilization in Legume Inclusive Cropping Systems

Among other benefits, legumes contribute nitrogen (N) to subsequent crops. However, predicting the impact on yield and the timing of the N release is difficult. Regardless, adjustments in the N recommendation need to be made to avoid yield and crop quality problems, as well as negative environmental and social issues. Ideally, a reduction of pre-plant/early season N fertilizer is made based on field research. Two possible approaches are used, namely the Fertilizer Replacement Value (FRV) or t... B. Hopkins, J. Stark

108. Soil Respiration Tests As Predictors of Nitrogen Mineralization Potential

Estimation of seasonal N availability via a soil test has proved difficult. This information gap has lead to fertilizer recommendations based upon soil inorganic N levels found before planting and or preside dress. Complicating matters, as famers adopt new irrigation technologies, the results from older fertilizer rate trails may also be less applicable. In general, most when not all recommendations do not account for the contribution of soil N mineralization during the growing season, which ... W. Horwath

109. Cover Cropping in the Semi-arid West: Effects of Termination Timing, Species, and Mixtures on Nitrogen Uptake, Yield, Soil Quality, and Economic Return

Summer fallow still dominates some areas of the northern Great Plains (NGP), providing an opportunity to grow a partial season cover crop for increased soil health or nutrient availability. Over 12 years of research on single species cover crops in semi-arid Montana have revealed the benefits of early termination and multiple cover crop cycles on N availability, subsequent crop yield, soil health, and economic return. Due to high N fixation, pea cover crops have fairly consistently increased ... C. Jones, P. Miller, S. Tallman, M. Housman, C. Zabinski, M. Burgess, J. O'dea, A. Bekkerman

110. Salt and Sediment Balances in an Irrigated Watershed in Southern Idaho

The quality of irrigation return flow in a 205,000 acre southern Idaho watershed has changed since 1970. Converting from furrow irrigation to sprinkler irrigation and installation of wetlands and sediment ponds have greatly reduced sediment loss. There is now more sediment in the irrigation water diverted into the watershed than returns to the Snake River (>100 lb a-1) compared to a net loss of 410 lb a-1 of sediment in 1971. There is also more soluble salt flowing into the watershed ... D. Bjorneberg, A. Koehn, J. Ippolito

111. Nitrogen Balances in Dairy Production Systems in Southern Idaho

Nitrogen (N) is essential for agricultural production, but excess quantities can be detrimental to both water and air quality. The increase in dairy cattle populations in the Magic Valley of southern Idaho has lead to concerns over the impact of N losses to the environment and the impact on both water and air in the region. This work examines the N flows and balances at the production facility, whole farm and regional scale. At the production facility, approximately 60% of N imported was lost... A. Leytem

112. Chloride Effects on Nitrogen Uptake in Potato Production

Potassium (K) can be supplied by potassium chloride (KCl) or sulfate (K2SO4) salts. Past research has shown that potatoes can take up and accumulate large amounts of chloride (Cl). Plant uptake of Cl can sometimes reduce petiole nitrate-N (NO3-N) concentration and it may have other effects on potato tuber yield and quality. In contrast, sulfate-S (SO4-S) typically does not compete strongly with NO3-N for plant uptake. This research was designed to evaluate the effect of Cl application on peti... D. Sullivan, S. Light, D. Horneck

113. Alfalfa Contributes More Nitrogen to Following Crop Than Previously Thought

Alfalfa in high-yielding environments fixes significant amounts of atmospheric N2, a portion of which benefits succeeding non-legume crops and reduces fertilizer N requirement by an amount sometimes called the “legume N credit”. Field research-based estimates of the legume N credit in California and other irrigated, semi-arid or arid environments are sparse in the literature. We conducted replicated plot experiments at three field station sites in California using wheat as an indi... S. Pettygrove, E. Lin, D. Putnam, M. Lundy, S. Orloff, S. Wright

114. Opportunities and Challenges: Using Soil Health Indicators to Guide On-farm Management

The USDA Natural Resources Conservation Service (NRCS) was founded in 1935 as the nation grappled with drastic depletion of soil resources in the Dust Bowl era. Initially called the Soil Conservation Service, the NRCS is a non-regulatory federal agency that offers technical and financial assistance to support conservation on private working lands. In August 2012, the agency rededicated itself to its roots in soil conservation by launching a Soil Health Initiative. ... K. Lowell

115. Utilizing Low Salt Liquid NPK Fertilizers to Establish Triticale As a Cover Crop

The use of cover crops in sustainable agricultural systems is receiving renewed attention. New initiatives in soil health promote cover crops as amanagement tool to improve soil quality and health. Successful establishment of cover crops depends on an adequate soil fertility program. Low salt NPK liquid fertilizers can improve cover crop establishment without concern of the impact of high salt index of some conventional fertilizers. This paper presents some of the success that have been obser... G. Mooso, T. Tindall

116. Nitrogen Nutrition Impact on Incidence of Rhizoctonia Infection of Agrostis Stolonifera

Creeping bentgrass (Agrostis stolonifera L.) is tolerant of short mowing and high traffic, but these conditions increase pathogen susceptibility. A prevalent disease on bentgrass golf course greens and tee boxes is Brown Patch (Rhizoctoniasolani). One potential component of integrated pathogen management is correct nitrogen (N) fertilization. Bentgrass was grown in a chamber hydroponically at deficient, optimum, and excessive levels of N (2.5, 10, and 80 mM; equivalent to 6.9, 27.5, and ... B. Hopkins, B. Black, B. Neville, C. Ewell, B. Geary

117. Applying a Phosphorus Risk Index in a Mixed-use Mountain Watershed

Surface waters in the Wallsburg, UT watershed have been identified as a relatively high contributor of phosphorus (P) to nearby Deer Creek Reservoir. Identifying the major contributors of P is critical for developing effective management practices. Phosphorus Risk Indices have been widely developed as a tool to identify areas with high risk of P movement, but these tools have mostly been applied to watersheds dominated by agricultural land use. While agriculture is often a source of nutrient ... A.W. Pearce, J. Johns, D. Robinson, N. Hansen

118. Summarization of 471 Field Comparisons of Avail®

Phosphorus (P) is a commonly deficient essential nutrient required for crop production. Economic, environmental, and conservation issues have motivated significant efforts to enhance fertilizer efficiency. AVAIL® is a specialty fertilizer product with claims of enhancing P use efficiency to potentially increase crop yield and quality. There have been at least 471 field comparisons to evaluate the effectiveness of AVAIL with a wide variety of crops. The objective of this summarization... B. Hopkins, K. Fernelius, M. Pryor

119. Effects of Post-fire Soil Hydrophobicity on Inorganic Soil Nitrogen and Sulfur Cycling

Fire plays an important role in many native ecosystems, and its suppression has increased woody encroachment across the globe. Restoring native herbaceous communities following fire in encroached systems is often challenging. Post-fire soil hydrophobicity is one factor that may further limit site restoration by limiting soil moisture, which may in turn affect soil nutrient dynamics. We conducted a field study in a burned pinion-juniper woodland to understand the effects of post- fire soil hyd... B. Hopkins, K. Fernelius, M. Madsen, K. Russell, B. Roundy

120. Turf Response to Reduced Rates of Polymer-coated Urea

Polymer-coated urea (PCU) is a controlled-release fertilizer which can enhance nitrogen (N) use efficiency (NUE), reduce N pollution, reduce the need for repeated fertilizer applications, and reduce turfgrass shoot growth and associated costs. A PCU fertilizer rated for 120 d was applied at 50, 75, and 100% of the recommended full rate and compared to an unfertilized control and urea, applied either all at once or split monthly at the full recommended rate. Spring applied PCU showed no initia... B. Hopkins, C. Ransom, M. Ruth, T. Blair, L. Sutton, D. Bradshaw, K. Campbell

121. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency and Yield Response in Crop Plants

Phosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past seven years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This paper will be a review of a portion of that data. Studies comparing CBP to ammonium polyphosphate (APP) and monoammonium phosphate (... B. Hopkins, T. Blair, J. Selman, C. Ransom, T. Hopkins

122. The Effect of Cyanobacteria Biofertilizer on Western Colorado Organic Peach Quality and Yield Characteristics

Nitrogen (N) is the nutrient needed by crops in the highest amounts and the production of synthetic N fertilizers contributes the highest proportion of carbon dioxide to the atmosphere, when compared to other sectors of agriculture. Cyanobacteria are naturally occurring in most ecosystems and fix nitrogen gas from the atmosphere into forms which are useable by plants. Cyanobacteria was applied along with irrigation water to organically farmed peach trees (Prunus persica cv. Suncrest) as ... D. Sterle, G. Litus, F. Stonaker, S. Ela, J. Davis

123. Effects of Commercial Organic and Cyanobacterial Fertilizers on Instantaneous Water Use Efficiency in Drip Irrigated Organic Sweet Corn

Water and fertilizers are applied to maintain crop growth, yield, and quality. Nitrogen (N) fertilizer plays a crucial role in crop growth and yield development of sweet corn (Zea mays). Organic growers often use commercial organic animal- based fertilizers which vary in nutrient composition, forms of available N (NH4+- N and NO3--N), and have high transportation costs. Alternatively, cyanobacteria can be grown on-site as a source of N. Cyanobacteria haves unique dual properties because ... J. G. davis, A. Sukor, C. Ramsey

124. Nitrogen Budgeting for Organic Production

Nitrogen management for high value vegetable crops under organic management is challenging. Organic systems rely on N mineralization processes in soil to deliver nitrate-N in adequate amounts with appropriate timing. The traditional nutrient management planning process (checkbook method: matching nutrient supply and demand over a production cycle) contains too many assumptions for accurate forecasting of plant-available N supply for organic systems. Organic fertilizers fall into thr... D. Sullivan

125. Evaluation of Nitrogen Gas Loss from Polymer Coated and Polymer Sulfur Coated Urea

Previous research showed reduced nitrogen (N) gas emissions from polymer coated (PCU) and polymer sulfur coated urea (PSCU) when surface applied to soil. To further verify and quantify (N) loss, experiments were conducted to measure N gas emissions. Fertilizer prills were surface applied in a semi enclosed system to allow atmospheric gases in but to prevent loss of N gases from the headspace. Nitrous oxide (N2O) and ammonia (NH3) emissions were continuously measured every 20 minutes using pho... B. Hopkins, J. Svedin, C. Ransom, J. Buss, T. Blair

126. Sensor-based Technologies for Nitrogen Management in Spring Wheat

Crop sensor-based systems with developed algorithms for making mid-season fertilizer nitrogen (N) recommendations are commercially available to producers in some parts of the world. Although there is growing interest in these technologies by grain producers in Montana, use is limited by the lack of local research under Montana’s semiarid conditions. A field study was carried out at two locations in 2011, three locations in 2012, and two locations in 2013 in North West Montana. The objec... O. Walsh, A. Pandey, R. Christiaens

127. Evaluation of Micro-carbon Technology-based P Fertilizer, Super Phos®, in Spring Wheat

Super Phos® (SP; 0-50-0) by Bio Huma Netics Inc. (Gilbert, AZ) is a Micro Carbon TechnologyTM – based phosphorus (P) fertilizer specifically formulated to resist “tie-up” with calcium (Ca) and magnesium (Mg) to remain water soluble and available to plant roots. The objective was to compare the efficiency and effectiveness of topdress and foliar application of SP, with traditional P fertilizers – ammonium polyphosphate (APP; 10-34-0), diammonium phosphate (DAP;... O. Walsh, A. Pandey, R. Christiaens

128. Environmentally Smart Nitrogen Performance in Northern Great Plains’ Spring Wheat Production Systems

Field trials were conducted at three locations in Montana to evaluate the efficacy of Environmentally Smart Nitrogen (ESN) (44-0-0) as a nitrogen (N) source for spring wheat. The ESN, urea (46-0-0), and a 50%-50% urea-ESN blend was applied at seeding at three rate levels - low, medium, and high - with actual rated dependent on the yield goal at each location, followed by urea application of 0 or 40 lb N/a at Feekes 5. Grain yield (GY) varied from 265 to 815 lb/a and grain protein (GP) content... O. Walsh, A. Pandey, R. Christiaens

129. Liquid N Fertilizer Evaluation in Spring Wheat

Several liquid N products are currently marketed for fertilization in various crops, including spring wheat. Urea ammonium nitrate (UAN) - the most commonly used liquid N fertilizer - is associated with crop damage due to corrosiveness. This study aimed to answer the following questions: (1) Are liquid urea (LU) and High NRG-N (HNRGN) superior to UAN in improving spring wheat grain yield and protein content? And (2) what is the optimum dilution ratio of foliar fertilizers and the threshold at... O. Walsh, A. Pandey, R. Christiaens

130. Soil Application of Zinc to Pecans in Calcareous Soils

Zinc deficiency is common in pecans outside their native range, especially in alkaline soils. Zinc-deficient pecan leaves have interveinal chlorosis or necrosis, decreased leaf thickness, and reduced photosynthetic capacity. Foliar Zn application is routine in Southwestern US pecan orchards. Soil Zn application has not been part of pecan management in high pH, calcareous soils because of the soils’ ability to adsorb soluble Zn. We are evaluating efficacy of fertigated chelated ZnEDTA in... J. Walworth, R. Heerema

131. Effects of Enhanced Mixing and Minimal Co2 Supplementation on Biomass and Nitrogen Concentration in a Nitrogen-fixing Anabaena Sp. Cyanobacteria Biofertilizer Production Culture

Nitrogen-fixing cyanobacteria are attractive as a nitrogen fertilizer because they are ubiquitous in nature and have minimal nutrient requirements. Our lab is scaling up production of a local strain of the nitrogen-fixing cyanobacterium Anabaena sp. in on-farm open raceways to determine its exonomic ppotential as a nitrogen fertilizer for horticultural crops. Our goal is to increase productivity in an organically certifiable growth medium above the current two week batch production l... J. G. davis, J. Wenz, H. Storteboom

132. Effect of Liquid Organic Fertilizers and Seaweed Extract on Daucus Carota Var. Sativus Growth Characteristics

Common N fertilizers used in organic production are often energy intensive to produce and expensive to transport. Cyanobacteria fertilizer produced on-farm could decrease impacts on the environment as well as production costs for organic farmers. In addition, cyanobacteria fertilizer could perform similarly to products marketed to increase production via plant growth hormones such as seaweed extract. The effects of common organic fertilizers as well as organic liquid cyanobacteria fertilizer ... J. G. davis, A. Wickham

133. Permanent Crops - Nutrient Management

In California, environmental regulations are rapidly expanding and moving into new areas of concern at a very rapid pace. Most recent requirements are based primarily on nitrogen and how it fits into a Nutrient Management Program (NMP). CCAs are being asked to assist growers in controlling nitrogen use to reduce/avoid its discharge to the environment. The Regional Water Quality Control Board of California classifies a discharge as lateral movement to surface waters or movement past the root s... K. Backman

134. Phytomanagement of Soluble Selenium and Production of Biofuel and Biofortified New Products

In many areas of the western US, excessive concentrations of soluble selenium (Se) in the environment can cause Se toxicity to biological organisms. The use of green plants to manage the soluble Se content in soils by plant uptake and biological volatilization has been considered as a cost-effective strategy. Importantly, the development of economically feasible remediation systems will encourage more widespread implementation of an integrated phytomanagement technology. The objective of this... G. Banuelos

135. Using Irrigation Nitrogen Credits for Grain Crops

Nitrogen contamination of surface and groundwater is not uncommon in many areas of the U.S. and Colorado is no exception. Nitrate-nitrogen (NO3-N) in groundwater is the most common form of plant available nitrogen (N), especially in shallow, alluvial aquifers in areas with intensive irrigated agriculture. When utilized as a primary irrigation water supply, this nitrate can contribute a significant portion of a crop’s N supply. Crediting water nitrate is part of Colorado N fertilizer rec... T. Bauder, R. Waskom

136. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency in Crop Plants

Phosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past five years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This presentation will be a review of that data. Studies comparing CBP to ammonium polyphosphate (APP) applied to soil show season-long in... B. Hopkins, T. Blair, M. Hill, C. Ransom

137. Advancing Nitrogen and Irrigation Management for Row Crops and Biofuel Crops in the Western US

Nitrogen, irrigation and N by irrigation studies from West Texas and central Arizona are discussed. In the first study with surface drip, deficit irrigation, N fertilizer rate response was observed with cotton (Gossypium hirsutum L.) in 50 and 75 % ET replacement, but not with dryland or 25 % ET. Irrigation level response was evident with LEPA in two of three years in Lamesa Texas, but not in a wet, third year. Variable-rate N showed a more consistent response than blanket-rate N in that... K. Bronson, J. Mon, D. Hunsaker, G. Wang

138. Development of Leaf Sampling and Interpretation Methods for Almond and Development of a Nutrient Budget Approach to Fertilizer Management in Almond

A five year research project on the use of N in orchards crops has been conducted to 1) to develop early season sampling protocols, and 2) to determine the response of Almond to various rates and sources of nitrogen (N) and potassium (K) fertilizers, 3) to develop nutrient demand curves and 4) to conduct a long term assessment of nutrient use efficiency with the goal of improving fertilizer management. Leaf and nut samples were taken at 5 stages of development throughout five seasons to deter... P.H. Brown, S. Saa, S. Muhammad, B. Sanden

139. Nitrogen Management in Blueberries

Three field trials were conducted in Corvallis, OR from 2006 to 2011 to evaluate nitrogen (N) fertilizer practices for establishment of highbush blueberry (Vaccinium corymbosum L.). In the first trial, planted in April 2006, we compared the effects of N fertigation (injection of fertilizer through a drip system) to conventional granular fertilizer application in ‘Bluecrop’ blueberry and found that fertigation produced more growth and less salt injury in young plants than gran... D. Bryla, O. Vargas

140. Irrigation and Nitrogen Management Web-based Software for Lettuce Production

Lettuce growers on the central coast of California are under increased regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of lettuce are the quick nitrate soil test (QNST) for monitoring soil mineral nitrogen levels and weather-based irrigation scheduling for estimating water needs of the crop. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage), to fa... M. Cahn, R. Smith, T. Hartz, B. Noel

141. Stratified Nutrient and Soil pH Education and Demonstration Project

Columbia County Washington is in the foothills of the Blue Mountain Range and the edge of the Palouse wheat country. The farming region soils are mostly a rich silt loam having a rainfall ranging from 10 inches in the north at the Snake River to 25 inches next to the Blue Mountains. About 90% of the cropping systems have migrated to some variation of conservation or reduced tillage. This has been good for the management of soil erosion but earlier intense soil sampling indicates that it may h... P. Carter

142. Inhibitors, Method and Time of Nitrogen Application for Improved Winter Wheat Production in Central Montana

The contribution of nitrogen (N) fertilizer to boost yield and improve quality is unquestionable. Inefficient use of applied N is economically significant and environmentally unsafe. Ammonia loss can exceed 40% of applied N. Nitrogen leaching is polluting wells. Use of urease and nitrification inhibitors along with appropriate timing and method of nitrogen application can reduce nitrogen loss, improve yield and quality of wheat. This experiment investigated the effect of timing and method of ... Y. Mohammed, T. Jensen, J. Heser, C. Chen

143. Nitrogen Transformations in Flooded Agroecosystems: a Case Study with Taro (Colocassia Esculenta)

Wetland agriculture covers an estimated 170 million ha and contributes significantly to global food supply. Nitrogen fertilizers are subject to numerous potential transformation pathways in flooded systems. The present research was focused on improving our understanding of N transformations in a flooded agricultural system by addressing the following two broad objectives: 1) determine whether the presence of anammox bacteria and its activity contribute significantly to N losses, and 2) evalua... J. Deenik, C. Penton, B. Popp, G. Bruland, P. Engstrom, J. Mueller, J. Tiedje

144. Use of Non-replicated Observations and Farm Trials for Guiding Nutrient Management Decisions

Replication or repetition is the means by which experimental error is estimated in replicated trials. In farm trials, it is sometimes not possible to replicate demonstration and test plots due to manageability and costs. In these situations, non-replicated observations and on-farm trials are used. In addition, nutrient response studies are often needed to calibrate the fertilizer requirement of a field. In this paper, we will define on-farm trials and observations, discuss the nature and unde... S. Machado, K. Girma

145. Exploring Controlled Release Nitrogen Fertilizers for Vegetable and Melon Crop Production in California and Arizona

Various forms of polymer coated urea (PCU) were examined as sources of controlled release nitrogen for production of cauliflower, watermelon, carrot, and spinach in Arizona or California. Studies were designed to demonstrate the effectiveness of PCU for supplying 100 percent of the fertilizer nitrogen needed for an entire growing season in a single pre-plant application. In each study, two or more N rates were tested. PCU having an appropriate release time for a given set of growing condition... R. Smith, A. Blaylock, E. Ellison, C. Sanchez

146. Nitrogen Dynamics in Conventional, Reduced Tillage and Organic Irrigated Systems: Results of a Four-year Experiment in Wyoming

Soil nitrogen (N) is critically important for crop production. A field experiment was conducted in eastern Wyoming to evaluate soil mineralizable (mineralized in 14 days incubation) and inorganic N contents as influenced by conventional, organic and reduced-tillage management approaches for cash-crop and forage production in eastern Wyoming. Soil samples were collected from all treatments (2 production systems x 3 management approaches) during 2009-2012 and analyzed for soil mineralizable and... R. Ghimire, J. Norton

147. Efficient N Fertility and Irrigation Management in Vegetable and Berry Production

Nitrogen (N) fertility and irrigation management for vegetable and berry production has historically been done on an ‘agronomic’ basis, with the sole focus on producing the optimal crop. For these crops N fertilizer and water costs are a small portion of overall production costs, and an even smaller portion of crop value; consequently, these inputs have not been scrutinized as closely as they have been for lower value crops. However, throughout the West concern over environmental ... T. Hartz, R. Smith, M. Cahn

148. Nitrogen Management in Wheat

Yields for current wheat varieties are quickly approaching 200 bu/a in high yielding environments. There are many approaches to managing nitrogen in wheat production systems using a variety of products on the market today. Urea, ESN, Agrotain, Arborite, DCD and many other nitrogen products are available for making sound agronomic decisions. Once the wheat plant is grown at about Fekes 7.0 there is the quandary of making protein when hard red winters or DNS types are grown. Choices become endl... D. Howneck

149. Soil Phosphorus Availability Differences Between Sprinkler and Furrow Irrigation

Water flowing in irrigation furrows detaches and transports soil particles and subsequently nutrients such as phosphorus (P). To reduce the risk of erosion and offsite P transport, producers in south-central Idaho have been converting from furrow to sprinkler irrigation. We completed research on soil P dynamics in furrow versus sprinkler irrigated soils from four paired-fields in the region. Surface soils (0-2.5 inches) were obtained from fields in September following barley harvest. Furrow i... J. Ippolito, D. Bjorneberg

150. Effect of Nitrogen Rate and Cropping System on Soil Nutrient Levels in a Long-term Study

Diversified continuous cropping systems in semi-arid regions of the northern Great Plains may enhance sustainability. A study initiated in 2000 in southwest Montana was designed to evaluate crop productivity and economic returns for no- till and organic rotations that included small grains, pulses, and oilseeds. Our specific objective presented here was to compare soil nutrient differences from 2004 to 2012, to learn if economically superior rotations were building or depleting soil nutrients... C. Jones, P. Miller, T. Rick, A. Mccauley

151. Reducing Nutrient Losses in Runoff from Furrow Irrigation

Few studies have comprehensively examined nutrient losses in runoff from furrow-irrigated fields, but the rising cost of fertilizer and finite nature of the resource encourages further research. A 2-yr experiment measured runoff losses of sediment, particulate P and N, and dissolved NO3-N, NH4-N, K, and reactive P (DRP) from fertilized, manured, or non-amended fields. Average nutrient losses were substantial, including 15.6 lbs ac-1 yr-1 dissolved N, P, and K and 73.6 lbs ac- 1 ... R. Lentz, D. Westermann, G. Lehrsch

152. Sidedress Nitrogen Management in Lima Beans

Different rates of sidedress nitrogen were applied to bush baby lima beans, with and without starter fertilizer and rhizobia inoculant in Yolo County, CA in 2012. Results documented that the use of starter fertilizer (nitrogen, phosphorus, and zinc) significantly enhanced yields compared to control plots without starter fertilizer. Use of rhizobia inoculant at planting did not result in enhanced yields compared with no inoculant. Sidedressing with ammonium sulfate at 20, 40, 60 and 80 lbs/acr... R. Long, R. Meyer

153. Differences in How Late Season Soil Vs. Foliar Nitrogen Fertilizer Supplements Affects Riesling Yan

During the 2011 and 2012 growing seasons, 0, 15, or 30 lbs/A N was applied in split applications as either soil (simulated drip) or foliar applications to a commercial Riesling vineyard with a history of low vine N. Each treatment was replicated 4 times. To assess the impact of the supplemental N applications on vine vigor, shoot lengths were measured weekly and pruning weights collected during the dormant season (2012/2013 pruning not yet conducted). Fruit was harvested within 2 days of comm... J. Davenport, M. Mccoy

154. Impact of an Enhanced Nitrogen Fertilizer (ESN) on Irrigated Crop Production in South Central Montana

Trials were conducted at the Montana State University Southern Agricultural Research Center in Huntley, MT using ESN (44% N, Agrium Advanced Technologies) in combination with urea (45% N) on three different irrigated crops: spring wheat, corn, and sugar beet. Each experiment was a randomized complete block with 4 replications using either 4 or 6 nitrogen rates in combination with 6 or 4 mixing ratios of ESN:urea, plus one unfertilized check for a total of 25 treatments. Urea and ESN were weig... K. Mcvay, K. Kephart, Q. Khan

155. Reliability of Soil and Plant Analyses for Making Nutrient Recommendations

Nutrient management is dependent on the collection of soil and plant samples for analytical testing and assessment. The quality of the analytical test are subject to bias and precision of the measurements made by the testing laboratory. Failure to understand lab analyses uncertainty can lead to over confidence in the management recommendation. Test uncertainty varies by soil and plant test methods utilized and by performance capability of the testing laboratory. Generally soil methods that pr... R. Miller

156. Integrating Fertilizer and Manure Nitrogen Sources in Irrigated Agriculture

Sharp increases in fertilizer prices are pushing growers to consider alternative nutrient sources for their crops. For growers in the western U.S. who produce crops in regions that also contain intensive animal production, manure can be a very affordable alternative nutrient source to chemical fertilizers. However, manure does not have the appropriate balance of nitrogen (N), phosphorus (P), potassium (K), and other nutrients to meet the nutrient needs of most crops. The goal of this article ... A. Moore

157. Soil Copper Thresholds for Potato Production

A rising concern with the application of dairy wastes to agricultural fields is the accumulation of copper (Cu) in the soil. Copper sulfate (CuSO4) from cattle footbaths is washed out of dairy barns and into wastewater lagoons. The addition of CuSO4 baths on dairies can increase Cu concentration significantly in manure slurry. The Cu-enriched dairy waste is then applied to agricultural crops, thus raising concerns about how soils and plants are impacted by these Cu additions. Repeated applica... A. Moore, M. Satterwhite, J. Ippolito

158. Phosphorus Use Efficiency in Crop Production

The limited availability of phosphorus (P) in calcareous and acidic soils can be a major factor that limits crop production. The objectives of this study were to investigate the mobility and availability of P from monoammonium phosphate (MAP), diammonium phosphate (DAP) and ammonium polyphosphate (APP) fertilizers alone and with AVAIL, a fertilizer enhancement product. Two different soil types were used to examine the relationship between P reaction products and available P. Soils were incuba... G. Mooso, T. Tindall, G. Hettiarachchi

159. Nutrient Efficiency Concepts for Phosphorus and Potassium

Two measures of phosphorus (P) and potassium (K) efficiency that are of interest to producers are agronomic efficiency (AE) and partial nutrient balance (PNB). Agronomic efficiency considers crop response to a nutrient addition while PNBmeasures nutrient removal to nutrient use. Proper evaluation of AE requires long term monitoring. A single, large application of P or K can, over many years, result in an AE similar to smaller, annual applications. A larger initial dose will inc... T. Murrell

160. On-farm Trials and Statistics

New technologies have made on-farm research easier to do. On-farm research networks exist in several states and are also being run by some national programs. These networks are becoming more common. University and/or government agency scientists and educators typically provide statistical expertise. Historical guidance for experimental design has focused on the randomized complete block design (RCBD). Statistical analyses that can be run easily are for an RCBD conducted in one site and one ye... T. Murrell

161. Climate Change and Nutrient Management

Climate change models for the intermountain region of eastern Oregon and Washington project warmer and wetter winters with warmer and drier summers. Crop response to the projected climate change conditions were estimated using CropSyst. The anticipated climate changes and increasing CO2 levels are projected to result in greater yields of winter wheat with relatively small changes in yields of spring wheat, potatoes and apples. Greater yields will require increased nutrient supply and inc... S. Petrie

162. Drinking Water Nitrate and Irrigated Agriculture in California

Nitrate contamination of groundwater in California has led to new government regulation of agricultural practices in the state’s Central Valley (CV) and Central Coast Regions (CC, which includes the Salinas Valley). Regulations in 2007 were imposed on dairies in the Central Valley, but more recently, all irrigated farming in both regions has been targeted. These regulations require monitoring and reporting (e.g., of fertilizer and manure applications), nutrient management plans, and adh... S. Pettygrove

163. Polymer Coated Urea (ESN): Impacts on Potato Crop and N Losses

Potato (Solanum tuberosum L.) production is sensitive to a steady, adequate supply of nitrogen (N). Synergistically optimizing grower profits while maximizing N use efficiency (NUE) is critical to conserve nonrenewable natural resources used to manufacture N fertilizer and minimize N pollution to water and the atmosphere. Polymer coated urea (PCU, Environmentally Smart N or ESN®) is one type of N fertilizer which uses temperature-controlled diffusion to control N release to better match p... B. Hopkins, C. Ransom, T. Taysom, J. Lemonte

164. Seasonal Water Distribution in a Drip-irrigated Cabernet Sauvignon Vineyard

Seasonal irrigation is vital to sustainable production of wine grapes in inland Washington. Without supplemental irrigation there is not enough rainfall during summer months to sustain plant health and productivity. Our 5 year project evaluates the effects of several regulated deficit irrigation treatments on soil water distribution throughout the growing season and the subsequent effects on yield and fruit quality in both Cabernet Sauvignon (CS) and Concord grapes; with a focus on wine grape... J. Davenport, J. Stout

165. Polymer Coated Urea (Duration) in Turfgrass: Impacts on Mowing, Visual, and Loss to Environment

Fall and spring applied N fertilizer trials were conducted over two years in an effort to determine if various slow and controlled release N fertilizers were equivalent to traditional urea and to determine if a reduced rate of controlled release N could be used for improved N use efficiency. An unfertilized control was compared to sulfur coated urea (SCU), polymer and sulfur coated urea (XCU), polymer coated urea (Duration 75 or 125; DR) at 50, 75, and 100% (full) rate, and urea either applie... B. Hopkins, L. Sutton, C. Ransom, T. Blair, J. Moody, K. Manning, S. Bergsten

166. Nutrient Management in Pecans

In the desert southwest, commercial pecan growers routinely apply supplemental nitrogen and zinc. Only 40% routinely apply phosphorus, and fewer use boron, iron, and copper. To evaluate nitrogen requirement, rates ranging from 130 to 390 lbs N/a were applied for three seasons in a mature orchard. Nitrogen treatments had little effect on leaf nitrogen concentrations, tree growth, or nut yield. The lower rate of nitrogen application was sufficient to keep leaf nitrogen levels in the sufficient ... J. Walworth

167. Development and Use of the OSU Organic Fertilizer and Cover Crop Calculator

Farm advisory visits in Oregon highlighted the need for decision tools to help farmers and agricultural professionals estimate nitrogen (N) mineralization from organic fertilizers and cover crops, design balanced fertilizer plans and identify the most cost effective nutrient management options. Laboratory and field research was conducted to develop N mineralization models for organic fertilizers and compost based on the total percent N. Field methods for estimating cover crop biomass and tota... N. Andrews, D. Sullivan, J. Julian, K. Pool

168. Soil and Plant Analysis: How They Fit into a “Green” Nutrient Management Program

Environmental concerns are changing the face of agricultural fertilization across the nation and world. Both nitrogen and phosphorus have become the major concerns in this area with other nutrients, salts, and chemicals being discussed for future regulations. The focus of environmental regulation depends on the characteristics of different geographical regions. Soil, water, and tissue analyses are needed to meet application requirements as regulatory documents are being drafted and implemente... K. Backman

169. Evaluation of Soil Salinity Conditions in California Central Coast Winegrape Vineyards

Soil salinity conditions in the winegrape vineyard areas of the California Central Coast were assessed by regional surveys of surface soils over multiple years, and by comprehensive evaluations of deeper salinity profiles at select locations. The multiple-year survey indicated that salinity conditions were increasing significantly, during a period characterized by below-average rainfall for the region. The survey also indicated that salinity conditions were at levels which would be expected t... M. Battany

170. Organic Management Improves Soil Health and Strawberry Nutritive Value

Soils and strawberries from 13 matched pairs of organically and conventionally managed fields were assessed over two years. Available plant nutrients were generally similar under organic and conventional management except that organically managed soils contained more available Zn and B. Soil C, N, and biological parameters were much greater under organic management. Organically produced strawberries matched by variety were smaller and had greater dry matter content than conventionally produce... L. Carpenter-boggs, J. Reganold, J. Reeve, P. Andrews

171. Boron Fertilization of Chile Pepper Under Greenhouse Conditions

Many chile (Capsicum annuum) growers apply boron (B) without knowing if B is actually needed. The application of B has been suggested to improve specific conditions that limit chile productivity such as alleviating blossom-end rot. Two varieties of chile were grown (159 days) under greenhouse conditions in silica sand and irrigated with seven levels of B (no B, 0.025 mg L-1, 0.05 mg L-1, 0.1 mg L-1, 0.25 mg L-1, 0.5 mg L-1, 1.0 mg L-1) and complete nutrient solution. Leaf B increased linearly... W. Lindemann, R. Flynn, C. Carr, R. Steiner

172. Highbush Blueberry Response to Compost and Sulfur

Highbush blueberry is adapted to soils with high organic matter and acidic pH, and it is often grown in Oregon with coniferous sawdust as a soil amendment or mulch. Composts could provide an alternative to sawdust, but acidification is needed to overcome high pH. Our objectives were to (i) predict the quantity of acidity needed to reduce compost pH to 4.8 (ideal for blueberry), (ii) determine compost characteristics suited for blueberry, and (iii) evaluate plant growth response and soil pH re... D. Sullivan, R. Costello, D. Bryla, B. Strik, J. Owens

173. Cover Crops for Nitrogen Management in Irrigated Cropping System

In perennial fruit cropping systems, the inter-row offers on opportunity to grow a cover crop that then can be used to supply nitrogen (N) to the fruit crop. We conducted research in both Concord grape and Gala apple to evaluate the potential of cover crops to supply N to the crop. Based on continuous monitoring of plant available NO3-N by using PRSTM ion exchange resin probes, we found that in Concord grape, while both hairy vetch and yellow sweet clover did not release quite as much N ... J. Davenport, K. Bair, D. Granastein

174. The Use of Biochar As a Fertility Amendment in Tropical Soils

Biochars made from modern pyrolysis methods have attracted widespread attention as potential soil amendments to improve plant productivity in the infertile soils of the tropics. Feedstock and pyrolysis conditions affect the physico-chemical properties of biochar with important implications for soil fertility and plant growth. Specifically, biochar volatile matter (VM) significantly affect soil inorganic nitrogen (N) status and ash content impacts soil elemental composition and pH. This paper ... J. Deenik, T. Mcclellan

175. An Excel Based Workbook for Assisting with Water Quality Interpretations

Clientele using the NMSU Soil, Water, and Agricultural Testing laboratory, as well other commercial labs, are usually given an irrigation water interpretation guideline in the form of a table with acceptable ranges. This approach, while helpful, does not quickly identify areas of concern to the client nor does it assist with estimating leaching fractions when salinity levels are high enough to warrant reclamation. A Microsoft Excel based workbook was developed to assist professionals and clie... R. Flynn

176. Forecasting Crop Nutrition Needs Using the Plant Root Simulator (PRStm) Technology

Conventional soil testing is based on the premise that a chemical extraction will reflect the soil nutrient supply to plants. The shortfalls of this approach have been evidenced by the numerous studies conducted over the past 50 years aimed at improving soil test methods. Radiotracer studies in the 1960’s where pivotal in shifting thinking away from nutrient concentration and toward mechanisms of nutrient supply. Barber (1995) first coined the term soil nutrient bioavailability&nbs... K. Greer

177. Crop Management Effects on Nitrous Oxide Emissions from Irrigated Systems1

The paper objective is to present an overview of the greenhouse gas research results from tillage and N fertility studies conducted by USDA-ARS on irrigated cropping systems near Fort Collins, Colorado from 2002–2010. Within agronomic N rates needed to optimize irrigated crop yields in the Central Great Plains, a linear increase in growing season nitrous oxide (N2O-N) emissions was observed from a clay loam soil with increasing fertilizer N rate. Averaged over a 5 yr period (2002-2006),... A. Halvorson

178. Regional Water Board Impacts on Vegetable Production in California

More than 300,000 ha of vegetable crops are produced annually in the coastal valleys of central California. In these valleys vegetable production dominates the landscape, and since most fields produce two or more crops per year the annual fertilizer input is very high. Not surprisingly, environmentally problematic levels of soluble phosphorus in surface waters, and nitrate-nitrogen (NO3-N) in both surface- and groundwater, are common. The Central Coast Regional Water Quality Control Board (WQ... T. Hartz

179. Efficient N Management for High-yield Vegetable Production

Vegetable production is an N-intensive industry; rates of N fertilization can be very high, particularly where multiple crops per year are produced. In vegetable production areas across the country high nitrate-nitrogen (NO3-N) concentration in surface water and groundwater is focusing regulatory scrutiny on fertilization practices. Furthermore, escalating energy prices mean higher N fertilizer costs, making efficient N management an economic as well as an environmental necessity. The basic p... T. Hartz

180. Evaluation of Soil-applied Eddha-chelated Iron Fertilizer for Use in Correcting Iron Deficiency Symptoms in Mature Pecan Trees in the Pecos Basin, New Mexico

Soils in the Pecos Basin of New Mexico are characterized by pH 7.5-8.5 and lime content 15-30%. Under these conditions pecan trees are prone to micronutrient deficiencies; pecan trees throughout the basin exhibit interveinal leaf chlorosis symptoms characteristic of iron (Fe) deficiency. In orchards where the Fe chlorosis symptoms occur, affected trees are typically scattered through the orchard in no apparent pattern. Foliar application of ferrous sulfate fertilizer sprays (as well as other ... R. Heerema, R. Flynn

181. Improving Phosphorus Use Efficiency with Carbond P

Phosphorus (P) fertilizer is integral for maximizing crop production and is used abundantly to achieve desired yields. However, reduction of P fertilizer is warranted, as it is the primary source of nutrient pollution in surface waters (eutrophication leading to hypoxia) and is derived from non-renewable mineral resources. Two research studies were conducted in 2009 to evaluate a new fertilizer product, Carbond® P against traditional fertilizers ammonium polyphosphate (APP) and monoammoni... B. Hopkins, B. Webb, M. Hill, C. Ransom

182. Advances in Nutrient Use Efficiency

The improvement of fertilizer efficiency is driven by narrow profit margins, environmental concerns, and resource conservation. Fertile soil is the foundation for food production and successful civilizations; it is developed and maintained through the addition of nutrients lost through harvest. However, nutrient uptake by plants is inherently inefficient and the nutrients remaining in the soil after uptake can cause negative air and water resource impacts. In addition, poor fertilizer efficie... B. Hopkins

183. Choosing Your Nitrogen Fertilizers Based on Ammonia Volatilization

Until recently we have not been able to measure ammonia volatilization without impacting the surrounding environment. In the past we have used closed chambers with acid traps. These closed chambers did not reflect surrounding weather conditions, at the minimum both temperature and wind were influenced. The use of the vertical flux method allows ammonia in the air to be monitored and modeled to reflect ammonia loss without any interference of the surrounding environment. ... D. Sullivan, D. Horneck, J. Holcomb, G. Clough

184. Ammonia Volatilization

Little work has been reported on the loss of ammonia from soils where fertilizers have been applied in an undisturbed environment. There are a multitude of studies that have used a chamber of some sort to estimate ammonia loss. The use of a chamber of some sort means that the environment has to be altered making the data derived suspect when translated into a loss number such as kg/ha. The advent of passive vertical flux method by Wood et al., 2000 at Aubrn University in Alabama, allows for t... J. Holcomb, D. Horneck, G. Clough, D. Sullivan

185. Biochar Usage: Pros and Cons

Soil fertility benefits of charcoal application have been reported as early as 1847 indicating that plant nutrients are sorbed within charcoal pores. The use of biomass-derived black carbon or biochar, the solid byproduct from the pyrolysis processing of any organic feedstock, has garnered recent attention as a potential vehicle for carbon sequestration and a beneficial soil conditioner. However, most of the past biochar research has focused on improving the physico-chemical properties of tro... R. Lentz, J. Ippolito, K. Spokas, J. Novak, H. Collins, J. Sterubel

186. Measured and Predicted Temporal Changes in Soil Nitrate-n Levels from Late Summer to Early Spring in Montana

Most soil sampling is conducted from August to November in Montana because of better soil sampling conditions and because it provides more time for growers to make fertilizer decisions prior to application. Fertilizer guidelines in Montana are based on spring nitrate-N levels in the upper 2 ft because they are more indicative of growing season available N than fall nitrate-N levels. It is not known how much nitrate-N levels change between late summer and spring, nor is it known what factors a... C. Jones, A. Lenssen, C. Chen, K. Mcvay, B. Stougaard, M. Westcott, J. Eckhoff, J. Weeding, M. Greenwood

187. Managing Alfalfa Under Low Water or Drought Conditions

There are several aspects to managing alfalfa during drought, or periods of limited irrigation, all of which apply whether or not the alfalfa is drought stressed (Lauriault et al., 2009). Most of these will be more related to stand longevity – helping the alfalfa to ride out the drought and still likely be productive once water is available again. The points covered in this session are: 1) Harvest Management; 2) Variety Selection; 3) Fertility; 4) Weed Management; 5) Water Management... L. Lauriault

188. Emissions of Ammonia and Greenhouse Gasses from Dairy Production Facilities in Southern Idaho

Idaho is one of the top three milk producing states in the United States. While this commodity group is a very valuable part of the economy, there is concern over the impact of these production facilities on the generation of ammonia (NH3) and greenhouse gases (methane, CH4 and nitrous oxide, N2O) which are linked to air quality degradation and global warming. To gain a better understanding of the on-farm emissions from these production facilities, we monitored both cattle housing and ma... A.B. Leytem, D. Bjorneberg, R.S. Dungan

189. The Dos and Don’ts of High Residue Farming in the Irrigated Far West

... A. Mcguire

190. Influence of Dairy Manure Applications on Corn Nutrient Uptake

Corn silage is the predominant crop in Idaho used for recovering phosphorus (P) that has accumulated in soils from dairy manure applications. However, little is known about how much phosphorus and other nutrients are being recovered under Idaho conditions. The objective of the study is to estimate phosphorus removal by irrigated corn silage crops cultivated throughout Southern Idaho with variable soil test P concentrations, and to identify effects of increasing soil test P on potassium (K), c... A. Moore, B. Brown, J. Ippolito, S. Hines, M. De haro marti, C. Falen, M. Chahine, T. Fife, R. Norell

191. Nitrogen and Phosphorus: Mechanisms of Loss from the Soil System and Effects to Slow Those Losses and Increase Plant Availability

Nutrient management issues associated with production agriculture are becoming more of a concern and a focal point of discussion. Management considerations are no longer focused on just meeting yield goals or improved crop performance, but now include questions on how their use on agriculture lands impacts surface water, watersheds, soil quality, long-term health benefits and economic viability for the producer. ... T. Tindall, G. Mooso

192. Utilizing Food Processing By-products As a Soil Amendment: Soil Nutrient Availability

We studied the impact of food processing by-products which contain high moisture content, low pH, high total dissolved salts, and trace elements. The primary goal of this project was to develop best management practices for sustainable reuse of food processing by-products as a soil amendment on California farmlands. Quantifying soil nutrient availability from these by-products is critical to growers to carefully establish fertilizer replacement value to improve their crop nutrient use efficie... S. Pasakdee, N. Dellavalle

193. K Fixation and Significance for Crop Production

Some cultivated soils in California found on the east side of the San Joaquin Valley (SJV) and derived from granitic parent material have the capacity to fix added K, making it unavailable or less available to crops. The main soil mineral responsible for K fixation is vermiculite, which is a weathering product of mica, and which can occur in the clay, silt, and fine-sand size fractions. We have developed a model that predicts the location of K-fixing soils in the region and a practical soil t... S. Pettygrove, T. O'geen, R. Southard

194. Dicarboxylic Acid Polymer (Avail®) Phosphorus Fertilizer Additive: Review

Improving P use efficiency (PUE) is desirable but difficult due to poor P solubility in soils. A dicarboxylic acid copolymer (AVAIL®) fertilizer additive may enhance PUE due to increased P solubility as a result of sequestering of interfering cations. Field trials have been conducted on a wide variety of crops, with results to AVAIL addition to P fertilizer mixed—seemingly related primarily to soil test P concentrations and fertilizer P rate. Positive results were seen in many of th... B. Hopkins, C. Ransom

195. Deficit Irrigation in Vineyards of Washington State

In Washington State the primary wine grape producing areas lie within the rainshadow of the Cascade Range and receive little precipitation throughout the year and especially during the summer. Wine grape producers take advantage of the arid conditions and use irrigation management to control vine growth and vigor. The precise control of irrigation timing and amount also affects the wine making characteristics of the fruit produced. A Cabernet Sauvignon (Vitis vinifera L) vineyard was use... B. Riley, R. Smithyman, J. Harbertson

196. Sheep Grazing Effect on Dryland Soil Carbon and Nitrogen in the Wheat-fallow System

Weed control by sheep grazing during fallow periods in the dryland wheat-fallow system may influence soil C and N levels. The effects of fallow management for weed control and soil water conservation [sheep grazing (grazing), herbicide application (chemical), and tillage (mechanical)] and cropping sequence [continuous spring wheat (CSW), spring wheat-fallow (SW-F), and winter wheat- fallow (WW-F)] on wheat biomass (stems + leaves) yield and soil organic C (SOC) and total N (STN) at the 0-120 ... A. Lenssen, U. Sainju, H. Goosey, E. Snyder, P. Hatfield

197. Predicting Plant-available Nitrogen Release from Cover Crop Residues

Improved methods are needed to estimate the timing and amount of plant- available N (PAN) release from cover crops. The OSU Organic Fertilizer and Cover Crop Calculator, a downloadable spreadsheet tool, assists agricultural professionals in estimating N fertilizer replacement value of organic inputs. We conducted a series of laboratory incubations with cover crop biomass incorporated into soil to determine: (i) speed of PAN release, (ii) amount of PAN release, and (iii) robustness of the OSU ... D. Sullivan, N. Andrews, R. Datta, K. Pool

198. Polymer Coated Urea: Impacts on Water/air Quality with Surface Applicaton to Permanent Sod

Nitrogen (N) is the most commonly used fertilizer and is essential to sustain the world’s populations. However, inherent inefficiencies in the soil-plant system result in losses of N to air and water, which can result in environmental quality problems. Two permanent sod turfgrass sites were fertilized with coated and uncoated urea and compared to an unfertilized control at 224 lb-N/ac. The polymer coated urea (PCU) was Duration 45 CR®. Fertilization resulted in increased growth and ... B. Hopkins, J. Lemonte, J. Summerhays, V. Jolley

199. Effectiveness of Soil-applied Zinc for Pecans

Pecan trees [Carya illinoinensis (Wangenh.) K. Koch] are very sensitive to Zn deficiency when grown in alkaline soils due to the formation of insoluble Zn hydroxides and carbonates which have low availability to pecan roots. We tested the efficacy of soil applied Zn-EDTA, Zn-Avail®, and ZnSO4 plus animal manure for supplying Zn to young pecans. Zn-EDTA supplied adequate Zn to potted pecan trees for one season only. The other soil Zn treatments had no appreciable effect. A soil s... J. Walworth, H. Nunez moreno, K. Stevens

200. Evaluation of Irrigation Application Management Practices to Protect Groundwater Quality

Agricultural management practices relative to irrigation application and type and frequency of nitrogen fertilizer application can impact levels of nitrates in groundwater. In recent history, high levels of nitrates were reported in public water supply wells in Goshen County, WY. Subsequent research efforts concluded that likely sources of nitrate were organic soil nitrogen and ammonium or nitrate fertilizer. Some focus was then turned to agricultural production higher up in the watershed. Be... K. Reddy, A. Wann, C. Wenzel

201. Delivery of Soil Science to Farmers Using Advanced Simulation Tools: a 10 Year Case Study

Technologies that aid in farm management and input application can increase profitability only if they readily show an advantage that the farmer can measure (Walton 2010). Western Ag Labs Ltd. (WAL) is a soil science laboratory which provides an educational soil service to producers of Western Canada using the PRSTM Technology. The service provides their customers access to advanced simulation tools that serves as a decision support system for Crop Nutrition Planning (CNP). The PRSTM technolo... K. Greer, D. Wildfong, D. Hicks, E. Hammermeister

202. Comparison of Three Buffer Methods to Determine Lime Requirement in Columbia Basin Region of Washington State

Weakly buffered soils of Washington State that have seen considerable pH change over the years due to use of ammonia based fertilizer products. Because these soils are weakly buffered and lime (CaCO3) requirement (LR) tests commonly report no lime is needed, a test that is sensitive enough for these conditions is preferred. Also, reagents used in some lime buffer methods are carcinogenic and/or toxic. A new buffer (Sikora) has been developed to work similarly to the commonly used SMP, but wit... K. Bair

203. Alfalfa Tissue and Seed Yield Response to Applied Boron

Alfalfa seed production can be limited by low boron (B) and information on tissue tests used for indicating B needs is lacking. Alfalfa seed trials were conducted in 2007 and 2008 in a silt loam to compare B concentrations in reproductive tissues (buds and flowers) with more traditional upper stems for reflecting available B. Factorial combinations of mid April knifed-in B (main plots) at three rates and four subplot foliar B timing treatments (non-treatment or 0.4 lb B/A at bud, flowering, a... B. Brown

204. Nitrogen Timing for Boot Stage Triticale Forage Yield and Phosphorus Uptake

Optimal N timing for boot stage winter triticale forage production and phosphorus (P) removal is not well established. Irrigated winter triticale in low and relatively high Olsen P soil was treated with six rates of fall pre-plant N and two rates of late winter N at Parma in 2006 and 2007. Triticale boot stage biomass, protein, nitrate-N, P concentrations, and P uptake and were determined. Fall preplant N increased forage production and frequently produced more boot stage triticale biomass. I... B. Brown

205. Phytosiderophore Exudation from the Roots of Iron Stressed Kentucky Bluegrass

Some Kentucky bluegrass (Poa pratensis L., KBG) cultivars are susceptible to iron (Fe) deficiency chlorosis when grown on calcareous soils and are routinely treated with Fe fertilizers. Aesthetics could be improved and this costly practice could potentially be eliminated with the use of cultivars resistant to Fe deficiency. Grasses are known to release phytosiderophore into the rhizosphere to dissolve Fe for plant use, and this characteristic has been used to screen for resistan... B. Hopkins, E. Buxton, V. Jolley, R. Christensen

206. Micro-nutrients in Alfalfa Production: is There Need/opportunity for Cost Effective Management?

The management of soil fertility for optimum alfalfa productivity requires that all nutrient-related limitations be manipulated where warranted and cost-effective. It has been the policy of the Utah State University Analytical Laboratory to not promote soil testing for micronutrient sufficiency based on a lack of general need, historically, for nutrients such as sulfur, boron, zinc and others. This study undertook to accomplish two things, 1) to provide an initial inventory of micro... G. Cardon, J. Barnhill, M. Pace, C. Israelsen, D. Miner, L. Greenhalgh, S. Banks, M. Shao, D. Rothlisberger, S. Olsen, P. Hole

207. Demonstration of Veris Nir Soil Carbon Mapping Technology

The new VERIS Technologies Near Infra Red (NIR) Spectrophotometer compares soil spectral measurements with soil carbon (C) and other properties. These data can be utilized to generate maps of soil characteristics across the landscape. This potentially useful system may simplify the measurement of important soil properties, provide a new tool for evaluation of residue conservation management practices, and guide farmers in soil management decisions based on data heretofore unavailable. While g... P. Carter, S. Van vleet, E. Perry, S. Young, F. Pierce

208. Biochar Volatile Matter Content Effects on Plant Growth and Nitrogen Transformations in a Tropical Soil

Biochars made from modern pyrolysis methods have attracted widespread attention as potential soil amendments with agronomic value. A series of greenhouse experiments and laboratory incubations were conducted to assess the effects of biochar volatile matter (VM) content on plant growth, nitrogen (N) transformations, and microbial activities in an acid tropical soil. High VM biochar inhibited plant growth and reduced N uptake with and without the addition of fertilizers. Low VM charcoal supplem... J. Deenik, A. Mcclellan, G. Uehara

209. Comparison of Induced Sludge Bed (Blanket) Anaerobic Reactor to Vertical Plug Flow Technology for Animal Manure Digestion1

The purpose of this study was to compare Induced Sludge Bed Anaerobic Reactor (IBR) (Hansen, Hansen, 2005) animal manure digestion technology to Vertical Plug Flow (VPF). In 2008 an IBR system at Sunderland Dairy Farm in Chester, Utah was repaired and retrofitted by Utah State University (USU), Extension, Utah Science, Technology and Research Initiative (USTAR), and Sunderland Dairy Farm. This was the first time research has compared IBR and VPF digester performance at a single site in a side... J. Gale, P. Zemke, B. Wood, S. Sunderland, S. Weeks

210. Phosphorus Dynamics in Organic Matter-amended Soils

Generally, phosphorus (P) is considered immobile in calcareous soils. Yet, numerous studies have found that the addition of organic wastes (e.g. manures) can enhance P mobility in these soils. We believe that the soluble organic matter present in these wastes increases P solubility by inhibiting the sorption of inorganic P on soil colloidal surfaces and subsequently preventing the formation of insoluble calcium phosphates. This results in increased P bioavailability. Likewise, tests used to a... P. Grossl, R. Koenig, C. Jones, S. Trolove

211. A Low Volume Continuous Gradient Dosing System for Rapid Plant Response Screening

Early tolerance experiments required a tedious and time consuming delivery process that additionally limited the number of replications and treatments performed (DeMalach et al., 1996). Many treatment delivery systems have been used in tolerance screening experiments, the more flexible of these being a trickle irrigation system known as the double emitter source (DES), or double drip line system. The techniques of the DES were adapted in this study by providing for a larger number of treatmen... A. Hawks, G. Cardon

212. Ammonia in the Columbia River Gorge

Air in the Columbia River Gorge (CRG), a national monument, is impacting vegetation, haze and even rock hieroglyphs. Air quality in the CRG is derived from three geographical locations, the Gorge itself, West of the Cascades and East of the Cascade Mountains. Paper mills, power plants, wood burning stoves, forest fires, combustion engines, agriculture... all contribute to CRG haze. Ammonia is an important player in CRG haze. Ammonia combines with NOx and SOx to form ammonium sulfate and ammon... D. Horneck

213. Economic Model to Determine Optimum Nitrogen Rates for Small Grains

Nitrogen (N) fertilizer is generally the highest input cost for Montana grain growers; therefore, it has become imperative that a tool be developed to assist crop advisers and farmers in determining economically optimum N rates (EONR). Data from all available MSU-conducted N fertility trials were gathered for spring wheat, winter wheat, and barley. Only the data sets for dryland fields following fallow were deemed large enough to have confidence in any resulting models, and all other data wer... C. Jones, D. Griffith, G. Jackson

214. Economics of Fertilization Under Site-specific Management Zones

Site-specific management of crop fields using variable rate application of inputs to manage in-field variability has now been around for over 15 years. However, the degree to which site-specific management strategies increase farm profitability is not well established. The objectives of this study were: to compare uniform and variable-rate Nitrogen (N) management strategies across productivity level site-specific management zones and to identify the most profitable N management strategy. This... R. Khosla, D. Westfall, W. Frasier, B. Koch

215. Residual Soil Nitrate and Potato Yield with Polymer Coated Urea

Potato (Solanum tuberosum L.) requires steady, but not excessive nitrogen (N) supply for maximum tuber yield, size, and solids, as well as minimal internal and external defects. Although more costly and labor intensive than dry broadcast applications, growers typically apply a majority of N via fertigation. A controlled release N fertilizer, polymer coated urea (PCU), is a possible alternative to this growers’ standard practice. A newly formulated PCU may meet plant demand... B. Webb, B. Hopkins, J. Lemonte, T. Taysom, V. Jolley

216. Elemental Sulfur with Iron: Kentucky Bluegrass

Iron (Fe) is known to improve greenness of Kentucky bluegrass (KBG; Poa pratensis L.), although applications are relatively costly and labor intensive. A new fertilizer material, elemental sulfur impregnated with Fe (ES-Fe), may provide an alternative source of Fe for KBG. The effects of ES-Fe on KBG was evaluated comparing 55 lb-Fe ac-1 ES-Fe to ferrous sulfate (FS) at the same rate and chelated Fe as a foliar (CF) or soil applied (CS) in a glasshouse study. A separat... B. Hopkins, B. Webb, K. Marcroft, R. Christenson, V. Jolley

217. Biofuel Byproducts As Nitrogen Sources for Crops

The new development of ethanol and biodiesel plants in the United States is creating a large, and potentially excessive, quantity of byproducts in the forms of distillers grains and oilseed meals. The organic nitrogen (N) compounds in these byproducts rapidly mineralize in soils, showing the potential to be used as a N fertilizer source to plants. The objective of this research is to evaluate the application of biofuel byproducts on yield, size distribution, and nutrient uptake for Russet Uma... A. Moore, A. Alva, H. Collins, R. Boydston

218. An Evaluation of the Effects of Diversified Cropping Systems on Soil Organic Matter, Nutrient Dynamics, Yield and Economics of Dry Land Winter Wheat and Irrigated Sugar Beet in Wyoming

The overall objective of this study is to evaluate the effects of different cropping systems and irrigation methods used by Wyoming farmers on soil chemical, biological and physical properties, yield, economic returns and long term ecological sustainability of dryland and irrigated crop production. The Project, which is being carried out on dryland winter wheat systems in the Albin and Slater areas and on irrigated sugar beet systems in the Big Horn basin near Powell, will ... J. Norton, E. Mukhwana

219. Waxy Barley: N Applications for Yield, Beta-glucan, and Protein

Nitrogen fertilizer (N) management was evaluated for growing irrigated waxy barley for higher protein and beta-glucan soluble fiber content. A local company has proposed the building of a barley fractionation plant to capitalize on these value-added traits. Salute and Merlin, two spring waxy barley cultivars, were fall-planted to compare yield and quality under different N treatments applied in late winter and at heading and to evaluate ethephon to reduce lodging. Fairly normal winter weather... S. Norberg, B. Brown, C. Shock, A. Ross, P. Hayes, J. Rey

220. Dig It! the Secrets of Soil a Primer on the Smithsonian Soils Exhibit

This past summer the Soil Science Society of America (SSSA) opened an exhibition entitled, “Dig It! The Secrets of Soil”. It resides at the Smithsonian Museum of Natural History in Washington D.C., and represents a huge step forward in our Society’s efforts to educate youth about soils and to pique their interest in studying soils. ... G. Peterson

221. Comparing Nutrient Availability in Low Fertility Soils Using Ion Exchange Resin Capsules and Plant Bioavailability Under Greenhouse Conditions

Commonly used soil resin analysis procedures have generally been developed to determine nutrient levels in agriculture soils. The purpose of the resin capsule procedure is to determine the amount of nutrient that correlates to that which is plant available. Desert soils contain lower levels of nutrients than agricultural soils, thus the validity of using resin capsules for desert soils is uncertain. In a previous incubation study it was determined that ion exchange resin capsules can be used ... B. Webb, B. Hopkins, M. Pletsch, D. Cook, M. Vickery, V. Jolley

222. Irrigated Small Grain Residue Management Effects on Soil Properties and Nutrient Cycling

The effects of straw removal from irrigated wheat and barley fields on soil properties and nutrient cycling is a concern due to its potential impact on the sustainability of agricultural production. The demand for animal bedding and the potential development of cellulosic ethanol production will likely increase straw demand in the future. Previous reviews addressing changes in soil properties when crop residues are removed focused primarily on rain-fed systems. This paper reviews published re... D. Tarkalson, B. Brown, D. Bjorneberg, H. Kok

223. Phosphorus and Zinc Interactions in Potato

Potato production requires high soil phosphorus (P) application with potential negative environmental and nutrient uptake effects. Impacts of high available P on species in potato cropping rotations are not adequately understood, nor have the causes of reduced yield and quality from excess P been fully explored. Antagonistic interactions with cationic micronutrients such as zinc (Zn) are plausible explanations. Two hydroponic experiments were conducted with Burbank potato to elucidate P and Z... B. Webb, B. Hopkins, J. Ellsworth, S. Barben, B. Nichols, V. Jolley

224. Agronomic Biosolids Application Rates for Dryland Wheat Across a Range of Northwest Climate Zones

Predicting agronomic rates is important to derive optimum economic and environmental benefits from biosolids fertilizer applications. We conducted this research to 1) evaluate dryland wheat response to biosolids applications over a range of climate zones in the Pacific Northwest and 2) compare agronomic application rates predicted from yield curves with those predicted from published extension guidance. We applied a range of biosolids rates during the fallow year in ten on-farm dryland wheat ... A. Bary, D. Sullivan, C. Cogger

225. Slow Release N for Irrigated Hard Red Spring Wheat Yield and Protein

Producing furrow irrigated hard red wheat with acceptable protein is challenging because of limited N management options for increasing protein. Slow release N has potential for improving N use efficiency in furrow irrigated hard wheat by avoiding the effects of excessive early season N yet providing later N for protein enhancement. A two year study (2005 and 2006) was conducted at Parma, ID to evaluate different N rates (120, 180 and 240 lb/A) of ESN and dry urea preplant N sources for furro... B. Brown, R. Gibson

226. Residual Phosphorus Effects on Alfalfa Seed Pollination and Production

Higher available P that increases alfalfa biomass reportedly reduces alfalfa seed yield due to poorer pollinator visitation. Available P effects were evaluated in a three year (2004-06) study with in-row plant spacing (12”, 24”, 36” and 48”) at Parma, ID to investigate the mechanism for the yield decline. Plots differing in residual P from previously applied P were further enriched with 0, 25, 50, 75, or 100 lb P/A. Plots were split in the last year and a mix of foliar... B. Brown, J. Barbour

227. New Tools in Soil and Manure Test Information Interpretation in Utah

An effort is underway to update the USU Analytical Laboratory’s (USUAL) procedures and data presentation/interpretation capabilities. Modern database management tools and analytical instruments have, in many cases, gone under-exploited in reducing sample turn-around time, in improving data dissemination and interpretation, and in providing research and extension personnel with access to comprehensive historical and current trend data on soil fertility, and manure and plant analysis.... G. Cardon, J. Kotuby-amacher

228. Spatial and Temporal Variability in Wine Grape Nutrients

Little work has been done to address the extent of spatial and temporal variability in nutrients in wine grape vineyards. In this study, we assessed soil and plant nutrient distribution on a per vine basis, both spatially and temporally across two vineyards, a Ruby Cabernet vineyard in Sunraysia and a Cabernet Sauvignon vineyard in Coonawarra. Petiole tissue was collected at two growth stages: flowering and veraison. Berry tissue was collected at harvest. All samples were analyzed for the pla... J. Davenport, R. Bramley

229. Non-destructive Measurement of Perennial Crop N Status

Little research has been conducted to evaluate the use on hand-held leaf meters as tools to assess plant N status in perennial crops. In this study, using replicated N rate plots in place for up to four years, we used two hand-held leaf meters (the Minolta SPAD meter and the Field Spec CM1000) to monitor tissue N status in apple and one meter (CM1000 only) in wine grape. In both crops, relationships were found between leaf meter readings and both fertilizer N rate as well as tissue N concentr... J. Davenport, R. Stevens, E. Perry

230. Variability of Manure Nutrient Content and Implications for Manure Sampling Protocol

The variability of manure nutrient levels within and across farms makes manure sampling and development of reliable tabular values challenging. The chemical characteristics of beef, dairy, horse, sheep, and chicken solid manures in Colorado were evaluated by sampling six to ten different livestock operations for each manure type and comparing the results to values found in the literature. Due to the semi-arid climate of Colorado, manure tends to be drier and have lower ammonium (NH4-N) levels... J. G. davis, K. Iversen, M. Vigil

231. Soil Testing to Improve Phosphorus Management on Intensive Vegetable Farms in Hawaii

According to a recent survey of soil samples sent to the Agricultural Diagnostic Service Center (ADSC) at the University of Hawaii between October 2002 and September 2003, a majority of the samples showed soil test P (STP) levels in the high or excessive categories. Despite high soil test P, many farmers in Hawaii continue to apply P fertilizers. We began a project to evaluate soil P status on a range of vegetable farms throughout the state, to determine crop response to P fertilizers on soil... J. Deenik, S. Fukuda, R. Hamasaki, R. Shimabuku, R. Uchida

232. Evaluating Potential Impacts of Land-applied Food Processing By-products on Soil Quality and Plant Nutrients

Food processing canneries, especially those using raw fruit, nut, and vegetable- base materials, generate various types of by-products or non-hazardous wastes. The constituents of these wastes are dependent on the source of raw material and the substances associated with the canning processes. The use of land-applied non-hazardous wastes as an agricultural soil amendment is projected to rise because of public concerns regarding environmental impact and economic restraints of their disposal to... S. Pasakdee, N. Dellavalle

233. Determining Plant Available Nitrogen from Manure and Compost Topdressed on an Irrigated Pasture

Composting manure is a practice that is gaining acceptance as an environmentally sound manure management practice at large animal production operations. Composting produces a value-added product that enhances the fertility and physical properties of soil. During the composting process, nitrogen and phosphorus in the original feedstocks are converted through microbial activity into predominantly stable organic compounds, lessening the risk of loss of these nutrients into the environment. Compo... J. G. davis, T. Bauder, K. Corwin doesken, A. Elliott

234. Best Management Practices (Bmps) for Ammonia Emissions Reduction from Animal Feeding Operations: a Colorado Case Study

Ammonia emissions from agriculture are a growing concern, in particular, in Colorado where nitrogen deposition in Rocky Mountain National Park has highlighted public concerns. Due to the high level of political pressure on agriculture to reduce its emissions, the agricultural community in Colorado has recently developed a Rocky Mountain National Park Ag Strategy for decreasing ammonia emissions from agriculture and nitrogen deposition in the park. The strategy includes the completion of a tho... J. G. davis, A. Elliott, N. Marcillac, J. Pritchett, C. Stewart, A. Mink

235. Soil Characteristics of New Mexico Vineyards: Management Implications

A growing viticulture industry in New Mexico has sparked a need to establish best management practices for the climate and soil conditions present across the state. A survey of soil and water characteristics in established New Mexico vineyards was performed so that appropriate management strategies could be developed and limitations could be identified. Soil nitrogen levels varied from low to high indicating potential problems. Plant tissue testing needs to be included in a phosphorus nutriti... R. Flynn

236. Cover Crops and Compost Amendments for Organic Grape Production

Increased costs of fertilizers that rely on petroleum products coupled with increased pest control and transportation costs has prompted more management practices that can make use of local waste products and utilize cover crops to reduce purchased inputs. A burgeoning wine industry could benefit from organic production techniques; however, their effects on vine growth and grape quality have not been explored in New Mexico. Alternative vineyard floor management systems were evaluated for orga... A. Ulery, R. Flynn, R. Walser, M. Weiss, S. Guldan

237. Nitrogen Cycling and Partitioning Under Alternative Organic Orchard Floor Management Strategies

Organic orchard systems are a significant and growing component of Washington State agriculture, yet sustainable methods of nitrogen (N) fertility and weed management remain a challenge. Nutrient supply is dependent on decomposition and mineralization of organic matter, yet intensive cultivation commonly used to control weeds can disrupt biological processes and cause loss of organic matter. To address the often-competing goals of organic fertility and weed control, a number of alternative or... L. Carpenter-boggs, D. Granatstein, J. Reganold, L. Hoagland, M. Mazzola, F. Peryea, J. Smith

238. Optical Sensing for Nitrogen Management

Although nitrogen (N) nutrition is as or more important than other nutrients, it has been largely ignored by those applying variable rate fertilizer (VRF) due to its loss potential for VRF applications that occur many weeks prior to crop need. Applications of N are best applied as close to crop uptake as possible in order to avoid leaching, denitrification, and other losses. Spatial variability for crop N need is often considerable due to differences in yield potential and, to a lesser degree... B. Hopkins, S. Stephens, A. Shiffler

239. Boron Fertilization in Potato

The high value of potato (Solanum tuberosum L.), its inefficient rooting system and the low organic matter content of sandy soils on which potatoes are cultivated result in widespread application of boron (B) and other micronutrients. However, in times of cost trimming, B may become an omitted input regardless of soil test values. Further, soil tests for B may need to be updated for higher yields, better management or improved soil test methods. Russet Burbank potato was grown a... B. Webb, B. Hopkins, J. Ellsworth, V. Jolley, R. Callahan

240. Precision N Management: Field-scale Application of N Efficiency Indices in Wheat

Preliminary evaluation of precision agricultural technologies showed that on-combine grain yield and protein monitors show promise as useful tools to characterize site- specific variations in crop performance. Variable rate applicators were shown to be proficient at achieving targeted site-specific application goals. First year comparisons of uniform versus precision N management in hard red winter wheat showed that similar yield and protein goals were met with 20% less applied N in the field... D. Huggins

241. Tillage Effects on Phosphorus Availability

Vertical stratification of phosphorus (P) has been documented in both no-till and reduced tillage systems, yet very few studies have determined if this stratification has affected P uptake, and none of these studies have been conducted in Montana. Stratification of P was compared in 1.2 in layers in a small plot study composed of four tillage systems: long-term conventional (sweep) till (CT), 10-yr no-till (NT), 1-yr NT and 1-yr CT. Olsen P was measured in the upper 12 in., and a sequential e... C. Jones, K. Neill, C. Chen, E. Allison

242. Urea and Ammonia Volatilization in Dryland Grass Seed Systems1

The purpose of this study was to evaluate the influence of grass seed production conditions and management practices on NH3 volatilization, Kentucky bluegrass seed yields and N recovery from urea. Laboratory incubations suggest the potential for NH3 volatilization is greater from stands in which post-harvest residue is baled and removed than from stands in which residue is burned. Both burned and unburned stands have a surface pH > 7.9, although pH declined with time in the burne... R. Koenig, C. Proctor, W. Johnston, C. Golob

243. Phosphorus Dynamics and Wheat Response to Applied P in a Spatially Variable Environment1

Considerable spatial and temporal variability exists in soil chemical and physical properties across farm landscapes in eastern Washington State. The purpose of this research is to investigate changes in P mineralogy across the Palouse landscape and ultimately to determine the influence of mineralogy on plant-available P and fertilizer P responses at different landscape positions. Soil samples were collected from landscape positions with varying soil pH and soil test P concentrations. Mineral... R. Koenig

244. Reducing Dairy Effluent Phosphorus Content Through Struvite Production

Forced precipitation of struvite (magnesium ammonium phosphate hexahydrate, MgNH4PO46H2O) in wastewater treatment has recently received increased attention as a method of phosphorus (P) recycling. Dairy lagoon P concentrations can be lowered, and the recovered struvite has the potential to be marketed and used as a fertilizer. Struvite may even be useful in organic production on calcareous soils, where rock P (PR) is not an option. A new organic treatment method, based on an exis... J. G. davis, J. Ippolito, M. Massey, R. Sheffield

245. Managing Potassium for Organic Crop Production

An adequate potassium (K) supply is essential for both organic and conventional crop production. Various organic certification agencies have different regulations governing allowable sources of K. The release of K from soil minerals is discussed along with the behavior of various allowed K sources for organic crop production. ... R. Mikkelsen

246. Cool Season Mineralization of Recalcitrant Organic N in Undisturbed Cores of Manured Soils

The objectives of this study were to (1) quantify cool season N mineralization from recalcitrant organic N in soils with a long history of manure application and (2) examine the relationship between cool season recalcitrant organic N mineralization and a fall mineralizable N index. “Cool season” was defined as October to February for fields with winter crops and October to May for fields with no winter crops. Two in situ trials were conducted with undisturbed so... D. Moberg, D. Sullivan, R. Johnson

247. No-till Grain Production in Wyoming: Status and Potential

In dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, or continuously, without fallow, but water and nutrient needs are much more closely balanced wi... J. Norton

248. Removing Nitrogen, Phosphate, and Fecal Coliform from Dairy Effluent Using Multi-soil-layer (Msl) Systems

Dairy effluent disposal has long been a concern in Hawaii. Dairies often establish multiple lagoons to accumulate and store effluent. Occasionally, the lagoons overflow leading to the transfer of nutrients, such as nitrogen (N) and phosphorus (P), and other contaminants such as pathogenic bacteria to surface, subsurface, and coastal waters. The objective of this study was to quantify the effectiveness of MSL systems in removing inorganic nitrogen, phosphate, and fecal indicator organisms (Fec... R. Yost, R. Pattnaik, G. Porter

249. Agronomic and Economic Comparison of Conventional and Direct-seeding in the Intermediate Rainfall Zone

The predominant dryland cropping system in the low (<12 inch) and intermediate (12- 18 inch) rainfall areas of the Pacific Northwest (PNW) is winter wheat (Triticum aestivum L.) summer-fallow using conventional tillage. Tillage increases the rate of soil organic matter oxidation which has an adverse effect on soil physical, biological and chemical properties. A field experiment comparing conventional tillage-based summer- fallow with chemical summer-fallow and direct-seeding ... S. Petrie, S. Albrecht, D. Long

250. Manure Treatments Change Nitrogen Cycling in Soils Receiving Repeated Applications of Dairy-wastes

Our objective was to assess effects of treated dairy-waste on soil N pools, nitrification, plant N availability, and yield in a silage cornfield treated with ammonium sulfate (AS), dairy-waste compost (DC) or liquid dairy-waste (LW) as N sources at two levels of application over 5 years. Increases in soil C and N, nitrate and available P and K were observed for the DC treated soils throughout the 5-year period. Soil organic C increases for the high-level DC treated soil doubled the C pool res... J. Norton, M. Habteselassie, J. Stark, B. Miller

251. Is Protein Enough for Assessing Wheat Flour Quality?

The quality of wheat products such as bread, bagels, noodles or pizza that consumers purchase is based on the flour quality used in production. Flours with different characteristcs are needed to produce different products and flour quality is important to produce a quality end product. However, at the initial stage of flour production, wheat is sold on a grain protein premium basis by farmers to elevators and eventually millers. In many years, higher protein (> 15% protein) wheat can bring... C. Reese, D. Clay, D. Beck, R. Englund

252. Grain Protein Content and Composition of Winter Wheat Cultivars Under Different Levels of N and Water Stress

This study investigated the combined influences and interactions of N fertilization and moisture deficit during grain-fill on wheat grain protein content and grain protein composition of nine white winter wheat cultivars. Grain was obtained from seven HWW wheat cultivars and two soft white winter (SWW) wheat cultivars grown under line-source irrigation systems at two Oregon locations during two years. The low N level treatment consisted in a single fertilization of 150 lb N/a in Mar... A. Ross, C. Saint pierre, C. Peterson, J. Ohm, M. Verhoeven, M. Larson, B. Hoefer

253. Predicting Phosphorus Runoff from Calcareous Soils

Studies have shown that as extractable soil P levels increase, runoff P levels also increase. This relationship has been found on many different soils, but tends to be unique for each soil series. Very little research exists evaluating this relationship in calcareous soils. The objectives of this study were to determine soil series specific relationships between soil test phosphorus (STP) and runoff P for three calcareous soils, to compare the use of different soil extractants for runoff P pr... J. G. davis, R. Schierer, J. Zumbrunnen

254. Remote Sensing of Grape K Deficiency Symptoms Using Leaf Level Hyperspectral Reflectance

Potassium (K) is an important nutrient for grape because it sustains charge neutrality during organic acid transport, is a major ion involved in osmoregulation and stomatal function and contributes to pH status in grapes and wines. We assessed the utility of a number of vegetation indexes for detection of K deficiency symptoms in a commercial vineyard of Vitis vinifera cv Pinot Noir. A hyperspectral field spectroradiometer for the 350-2500 nm spectral region was used to measure light reflecta... D. Smart, M. Whiting, C. Stockert

255. Evaluation of N Uptake Analysis As a Tool for Determing Potato N Status

Plant tissue testing has become the primary method for evaluating nitrogen availability for potatoes during the growing season. This study was conducted to determine if plant N uptake rates referenced to absorbed solar radiation could also be used as a tool to quantitatively assess plant N status of different potato varieties. Nitrogen fertilizer, as NH4NO3 (34-0-0), was applied to Russet Burbank, Gem Russet, Bannock Russet and Summit Russet at three rates (0, 100, or 300 kg N/ha) using ... J. Stark, S. Love, C. Mcintosh

256. Developing Extension Guidance for Management Effects on Ammonia Loss: a Computer Simulation Modeling Approach

Computer simulation models provide insight into ammonia loss processes and the sensitivity of ammonia loss predictions to environmental and management variables. As an example of how a simple computer simulation model can inform the Extension guideline development process, the ALFAM (Ammonia Volatilization from Field-Applied Animal Slurry) model was used to estimate NH3 loss from surface- applied municipal biosolids: liquid (3% dry matter) and dewatered (22% dry matter). Model ... D. Sullivan

257. Polymer Coated Urea in Potato Production

Nitrogen (N) is the most important mineral nutrient in potato (Solanum tuberosum) production. Studies show a steady, but not excessive, supply of N is important for maximum tuber yield, size, and solids, as well as minimal internal and external defects. Although more costly and labor intensive dry broadcast applications, growers typically apply the majority of N through the irrigation water in-season in order to maximize yield components. A controlled release N fertilizer, in the form of poly... B. Hopkins, T. Taysom, A. Shiffler, S. Stephens

258. Recent Advances in P Fertilizer Technologies—polymer Coatings and Avail Technology

Phosphorus fertilizers are an essential part of plant production and have been recognized as such for well over 100 years. Phosphorus utilization by crops is related to both soil availability as well as an individual plants metabolic process that allows P to be taken up by a plant as well as utilized for a wide variety of developmental processes. ... T. Tindall

259. Nutrient Cycling in Effluent-irrigated Soil (Mollisol) Planted to Tropical Grasses in a Tropical Island Environment

Dairy producers accumulate large quantities of effluent in lagoons. Lagoons occasionally overflow causing the nutrients and other contaminants in effluent to pollute the land and water bodies. Alternative uses of effluent are, therefore, urgently needed for a sustainable and environment-friendly dairy production. This study determined the sustainable effluent application rate and assessed the effects of effluent irrigation on plant and soil (Cumulic Haplustoll) properties. Five tropical grass... R. Valencia-gica, R. Yost, G. Porter, R. Pattnaik

260. Soil Zinc Application for Southwestern Pecan

Pecan trees grown in the alkaline soils of the southwestern United States are prone to zinc deficiency unless supplemental zinc is regularly applied. Standard treatment involves multiple foliar zinc applications. Soil zinc application would provide several advantages. A field study was initiated in 2005 with three soil zinc treatments: no zinc (control), ZnSO4 (74 kg.ha-1 Zn), or ZnEDTA (19 kg.ha-1 Zn) were applied one time in March, 2005 in bands 18 cm deep and 1.2 m on both s... J. Walworth, A. Pond, H. Nunez, B. Wood, M. Kilby

261. Remote Sensing of Corn N Status with Active Sensors

Determining in-season corn (Zea mays L.) nitrogen (N) variability has been a research focus of agronomists for quite some time. One of the methods currently available to determine N variability in corn is remote sensing. Studies have shown that remotely sensed imagery can detect N variability in corn. However, this method can have some limitations, such as the timeliness in which this imagery can be acquired. Hand-held active remote sensing devices may overcome these limitations... D. Westfall, R. Khosla, T. Shaver

262. Nitrogen and Phosphorus Fertigation on Pears

Avoiding over-application of nitrogen (N) and phosphorus (P) fertilizers and increasing N and P use efficiency on pear orchards have significant benefits on pear productivity and the environment. Split fertigation of N and P fertilizers and banding application of N and P fertilizers may increase the use efficiency of applied N and P fertilizers compared with our current N and P management system -- single broadcasting application of dry N and P fertilizers to the soil surface. A field experim... F. Yin, C. Seavert, J. Bai

263. Economics of Alfalfa Fertilization Under Inflated Hay and Fertilizer Prices

Knowing critical alfalfa nutrient levels in-season improves recommendations and applications, while at the same time saves producers time, expense and effort since many growers take samples for hay quality.  Inflation has doubled hay and fertilizer prices which brings into question how current fertility decisions are made. From 2019-2020 detail information on phosphorus and potassium response was conducted. Two experiments were designed as follows: 1) Phosphorus (P) rate study with diffe... S. Norberg, D. Llewellyn, J.P. Driver, S. Fransen, J. Harrison

264. Nitrogen Availability from Organic Amendments

Organic fertilizers and composts are valuable sources of nutrients. However, their nutrient availability is often not known and can be variable. How much nitrogen (N) becomes plant available depends on environmental factors, including temperature and so moisture, as well as the properties of the decomposing organic material. We investigated the effects of the carbon to N (C:N) ratio of different commercially available organic fertilizers and composts in a study where we mixed the materials wi... D. Geisseler

265. Variable Rate Fertilization: Soil Moisture Impacts

Variable Rate Fertilization (VRF) fertilization is a means of potentially applying nutrients more efficiently. Variable Rate Irrigation (VRI) is increasingly evaluated. However, these are generally studied in isolation, which seems contrary to the principles on which each are founded. Potential benefits of VRF, especially for N, are often confounded or repressed as a result of soil moisture variability due to runoff losses/accumulation and/or total water applied. Similarly, VRI results are im... B.G. Hopkins

266. Improved Small Grain Nitrogen Use Efficiency with California Site-specific Decision Support

Small grains are grown throughout the state of California (CA) on approximately 500,000 acres annually. They are generally fall-sown and grown during the winter months when most precipitation occurs. Because precipitation and irrigation patterns vary across CA and there is a strong interaction between total water and plant available nitrogen (N), determining fertilizer N application recommendations is particularly challenging in this cropping system. With recent fertilizer price vol... N. Clark, M. Lundy, T. Nelsen, M. Leinfelder-miles, S. Light, G. Galdi, T. Getts, K. Mathesius

267. Spoon-fed Nitrogen and Phosphorus Management for Subsurface Drip Irrigated Cotton (Gossypium hirsutum)

Subsurface drip irrigation (SDI) is becoming a popular option for maximizing the water use efficiency of cotton (Gossypium hirsutum), especially in semi-arid environments of the Midsouth and Western United States. Applying fertilizers through SDI provides an opportunity to prescriptively apply nutrients at peak nutrient demand which could minimize loss and increase uptake, but the application timing is poorly understood. The objective of this study was to develop nitrogen (N) an... J.A. Burke, K.L. Lewis

268. Monitoring Soil Nitrate to Estimate Cover Crop N Contribution in Organic Vegetable Production Fields

Organic vegetable growers rely on legume cover crops as an economical source of plant-available N. This research evaluated N contributions to summer vegetable crops by cover crops (CC) residues by monitoring soil nitrate (NO3-N) concentrations during the summer crop growing season. Replicated field plots were established with three CC mixes: solo common vetch (V),  phacelia + V (PV), and cereal rye + V (RV), plus a winter fallow (F) control in grower fields in the north Willamette V... D. Sullivan, N. Andrews

269. Performance of Public and Private Fertilizer Recommendations for Corn, Alfalfa, and Small Grains

There are many sources that growers utilize to determine fertilizer needs for crops such as private and public labs, crop advisors, and fertilizer dealers. In many cases, these sources provide recommendations for a specific crop that can vary greatly, and the resulting fertilizer and application rates recommended can lead to large differences in costs for the grower. Evaluating the effectiveness and economics of current fertilizer guidelines and recommendations will help growers to make bette... M. Yost, M. Baker, J. Gale, E. Creech, G. Cardon

270. Biosolids-based Fertilizers as a Nitrogen Source in California Small Grains Systems

Situation/ conditions In response to regulatory and economic pressure, California growers are becoming more familiar with nitrogen budgets. In addition to seeking out ways to improve nitrogen management strategies, growers can possibly benefit by incorporating alternative sources of nitrogen to feed their crops. Liquid injected or pelletized biosolids-based fertilizers from local waste streams and processing facilities are one source that growers are beginning to explore. ... K. Mathesius, D. Geisseler, M. Savidge, M. Lundy, T. Nelson, N. Andersen

271. Impact of Variable-Rate Nitrogen on Potato Yield, Quality, and Profit

Nitrogen application in agriculture is a vital process for optimal plant growth and yield outcomes. Factors such as: topography, soil properties, historical yield, and crop stress variably affect nitrogen (N) needs within a field. Applying variable N within a field could improve yields and nitrogen use efficiency (NUE). Optimal N management is a system that involves applying a conservative variable base rate at or shortly after planting followed by in-season assessment and, if needed, variabl... E.A. Flint, M. Yost, B. Hopkins

272. The Ammonia Rainbow

Agriculture has been identified as a major contributor to atmospheric carbon dioxide with nitrogen fertilizer production as a key component. Recent scrutiny of nitrogen production processes has identified ammonia production processes to reduce carbon output from traditional Haber-Bosch processes.  These different ammonia production processes are often described with color descriptions to designate the processes used and qualitatively identify their carbon footprint, such as “green ... A. Blaylock

273. Crystal Green® – the Most Efficient Granular Phosphate Fertilizer

Over 80% of applied conventional phosphate can be lost to soil fixation or the environment and leaves crops hungry for nutrients when they need them the most. Overapplying conventional phosphate fertilizers, produced from a finite resource, to overcome significant inefficiencies does not align well with industry goals of sustainability. Not only are crops missing out on proper plant nutrition of a critical nutrient, these nutrients are lost to the environment and are responsible for harmful a... G. Mooso

274. Helpful or Not?- Biostimulant Use in Corn Silage Production

There has been a recent increase in both the availability and marketing of biostimulant products to local producers, particularly to dairymen, in southern Idaho. These products claim to increase yield and nutrient use efficiency while improving soil health on agricultural fields. If these claims are true, the use of these products would ultimately aid in promoting the overall sustainability of Idaho farms. However, there is a lack of objective data to support these claims, leaving producers u... L.R. Schott, S. Hines, J. Packham, G. Loomis, M. De haro marti, C. Willmore

275. Variable Rate N and P Management for High-value Vegetable Cropping Systems

The Lower Colorado River Region (LCRR) of Arizona and California and their environs produce more than 90% of the nation’s cool season vegetables during the fall-winter-spring period. Large amounts of N and P fertilizers are currently utilized for maximum yield and quality.  Phosphorus fertilizers are applied pre-plant based on a soil test of a composite field sample.  Nitrogen is applied by side-dress based on a plant midrib or petiole N analysis, or soil nitrate-N test, from ... C.A. Sanchez, P. Andrade

276. Floral Hemp Responses to Nitrogen Fertilization in the High Desert

The performance of floral hemp under N fertilization is influenced by environmental conditions, management and cultivar selection. This field study evaluated the effect of no supplemental N and N fertilization at 90 kg ha-1 on three hemp cultivars (Berry Blossom, Red Bordeaux, and Tahoe Cinco) in Northern Nevada. Nitrogen increased plant height, canopy cover, stem diameter and shoot biomass, but other physiological parameters were dependent on cultivar. We evaluated the u... F. Barrios masias, M. Farnisa, J. Solomon, G. Miller

277. Effects of Long-term Biosolids Applications in Two Dryland Agroecosystems on Physical, Biological, and Chemical Soil Health Properties

Biosolids can be important sources of organic matter to semi-arid dryland grain systems and have the potential to mitigate some of the soil health challenges specific to these areas while providing an alternative to synthetic fertilizers. Biosolids are an important avenue for beneficially reusing and redistributing nutrients from high population urban areas to more rural agricultural areas. We explored how long-term (20+ year) applications of biosolids at two field sites affected physical, bi... M. Desjardins, A. Bary, J. Ippolito, S. Cappellazzi, D. Liptzin, D. Griffin-lahue

278. Optimizing Fertigation for High Value Crops

In irrigated farming systems, soluble and mobile fertilizers, such as sources of nitrogen, are often applied to crops through fertigation. Fertigation presents both opportunities and challenges. Potential opportunities include better synchronization of nutrient availability with crop demand through the growing season and potential energy savings. Challenges include the need for additional investment on infrastructure for nutrient injection into the irrigation conveyance and distribution syste... C.A. Sanchez, D. Zerihun

279. ManureDB: Creating a Nationwide Manure Test Database

Manure nutrients serve an important role in crop production, however compared with commercial fertilizers there is a lack of standardized information. When exact manure values are not known, manure book values have been referenced. Recent data from midwestern United States (US) labs indicates manure nutrient levels have changed from book values published by Midwest Plan Service (2004) and American Society of Agricultural and Biological Engineers (2005). Manure laboratory analysis has improved... N.L. Bohl bormann, M.L. Wilson, E.L. Cortus, K. Janni, K. Silverstein, L. Gunderson

280. CropManage Decision Support Tool for Improving Irrigation and Nutrient Efficiency of Cool Season Vegetables in California: a Decade of Field Demonstrations and Outreach

Vegetable growers on the central coast of California are under regulatory pressure to reduce nitrate loading to ground and surface water supplies.  California is also implementing the Sustainable Groundwater Management Act (SGMA) which may limit agricultural pumping in regions such as the central coast where the aquifer has been over-extracted for irrigation of crops.  Growers could potentially use less N fertilizer, address water quality concerns, and conserve water by improving wa... M. Cahn, R. Smith, L. Johnson, F. Melton

281. How Variable is Variable for Production Fields in Southern Idaho?

Idaho ranks in the top 10 in the US for dairy, potato, barley, hay, sugar beet, corn silage, and dry bean production. The highest producing areas in the state for these commodities are in Southern Idaho. Agricultural producers in this region, just like many other regions, are tasked with managing irrigation water and soil fertility on large fields with spatial heterogeneity in a way that results in homogeneous crop production.  ... L. Schott, C. Robison, E. Brooks, D. Bjorneberg, K. Nouwakpo

282. Flushed Liquid Dairy Manure Solid Particle and Nutrient Distributions

Large dairies often use liquid manure handling systems because of their ease of mechanization and low labor requirements. Some of Idaho Magic Valley dairies use flushing systems that result in large amounts of liquid dairy manure that are applied via irrigation systems to adjacent cropland during the growing season. Solids and nutrients found in liquid dairy manure pose challenges to manure handling processes and cause environmental concerns. Separating solids and nutrients from liquid dairy ... L. Chen, K. Kruger