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Collins, C
Pattnaik, R
Olsen, D
Sukor, A
Norton, J
Kerry, R
Pritchett, J
Ippolito, J
Kephart, K
Thurgood, G
Hansen, N
Hopkins, B
Zabinski, C
Mink, A
Burke, J.A
Tallman, S
Bronson, K.F
Andrews, N
Marcillac, N
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Authors
Miller, P
Jones, C
Zabinski, C
D'Agati, K
Housman, M
Tallman, S
Stapley, S
Hopkins, B
Ippolito, J
Shawver, C
Brummer, J
Ahola, J
Rhoades, R
Bronson, K.F
Bjorneberg, D
Olsen, D
Tarkalson, D
Rogers, C
Thurgood, G
Dari, B
Marshall, J
Walsh, O.S
Schroeder, K
Loomis, G
Norton, J
Rodgers, H
van Diepen, L
Bush, T.V
Crowe, V
Norton, J
Webb, B
Hopkins, B
Ellsworth, J
Barben, S
Nichols, B
Jolley, V
G. Davis, J
Elliott, A
Marcillac, N
Pritchett, J
Stewart, C
Mink, A
Hopkins, B
Stephens, S
Shiffler, A
Webb, B
Hopkins, B
Ellsworth, J
Jolley, V
Callahan, R
G. Davis, J
Ippolito, J
Massey, M
Sheffield, R
Norton, J
Yost, R
Pattnaik, R
Porter, G
Hopkins, B
Taysom, T
Shiffler, A
Stephens, S
Valencia-Gica, R
Yost, R
Porter, G
Pattnaik, R
Hopkins, B
Buxton, E
Jolley, V
Christensen, R
Webb, B
Hopkins, B
LeMonte, J
Taysom, T
Jolley, V
Hopkins, B
Webb, B
Marcroft, K
Christenson, R
Jolley, V
Norton, J
Mukhwana, E
Webb, B
Hopkins, B
Pletsch, M
Cook, D
Vickery, M
Jolley, V
Andrews, N
Sullivan, D
Julian, J
Pool, K
Hopkins, B
Webb, B
Hill, M
Ransom, C
Hopkins, B
Lentz, R
Ippolito, J
Spokas, K
Novak, J
Collins, H
Sterubel, J
Moore, A
Brown, B
Ippolito, J
Hines, S
de Haro Marti, M
Falen, C
Chahine, M
Fife, T
Norell, R
Hopkins, B
Ransom, C
Sullivan, D
Andrews, N
Datta, R
Pool, K
Hopkins, B
leMonte, J
Summerhays, J
Jolley, V
Hopkins, B
Blair, T
Hill, M
Ransom, C
Ghimire, R
Norton, J
Ippolito, J
Bjorneberg, D
McVay, K
Kephart, K
Khan, Q
Moore, A
Satterwhite, M
Ippolito, J
Hopkins, B
Ransom, C
Taysom, T
LeMonte, J
Hopkins, B
Sutton, L
Ransom, C
Blair, T
Moody, J
Manning, K
Bergsten, S
Carroll, A
Lindsey, C
Baker, J
Hopkins, B
Hansen, N
Blair, T
Ransom, C
Hosford, P
Svedin, J
Sutton, L
Winchester, A
Manning, K
Hopkins, T
Hopkins, B
Buss, J
Gish, J
Hopkins, B
Hopkins, B
Stark, J
Jones, C
Miller, P
Tallman, S
Housman, M
Zabinski, C
Burgess, M
O'Dea, J
Bekkerman, A
Bjorneberg, D
Koehn, A
Ippolito, J
Hopkins, B
Black, B
Neville, B
Ewell, C
Geary, B
Pearce, A.W
Johns, J
Robinson, D
Hansen, N
Hopkins, B
Fernelius, K
Pryor, M
Hopkins, B
Fernelius, K
Madsen, M
Russell, K
Roundy, B
Hopkins, B
Ransom, C
Ruth, M
Blair, T
Sutton, L
Bradshaw, D
Campbell, K
Hopkins, B
Blair, T
Selman, J
Ransom, C
Hopkins, T
G. Davis, J
Sukor, A
Ramsey, C
Hopkins, B
Svedin, J
Ransom, C
Buss, J
Blair, T
Campbell, C
Hansen, N
Hopkins, B
Evans, S
Campbell, E
Campbell, A
Rivera, L
Cobos, D
Hopkins, B
Hansen, N
Ippolito, J
Bjorneberg, D
Stott, D
Karlen, D
Svedin, J
Hansen, N
Kerry, R
Christensen, R
Hopkins, B
Shipp, E
Hopkins, T
Hopkins, B
Russell, K
Hopkins, A
Hansen, N
Hopkins, B
Bartholomew, S
Hopkins, T
Hopkins, B
Evans, S
Hansen, N
Blaylock, A
Youngquist, C
Norton, J
Harsh, J
Hopkins, B
Carlock, E
Weigel, A
Searle, T
Hopkins, T
Williams, J
Hopkins, B
Fahning, S
Searle, T
Weigel, A
Buck, R
Hopkins, T
Hopkins, B
Fisher, J
Woolley, E
Svedin, J
Hopkins, B
Hopkins, A
Campbell, C
Hopkins, B
Hansen, N
Norris, A
Hopkins, B
Stapley, S
Buss, J
Hopkins, B
Valencia, M
Nelson, S
Hopkins, B
Woolley, R
Svedin, J
Woolley, E
Hopkins, B
Woolley, E
Searle, T
Hopkins, T
Williams, J
Hopkins, B
Cole, D
Woolley, R
Buck, R
Hopkins, B
Burke, J.A
Lewis, K.L
Sullivan, D
Andrews, N
Collins, C
Loera, E
Reid, R
Spackman, J
Seely , C
Hopkins, B
Ioannou, J.D
Hopkins, B
Burke, J.A
Lewis, K.L
Foster-Malone, J.L
Flint, E.A
Yost, M
Hopkins, B
Desjardins, M
Bary, A
Ippolito, J
Cappellazzi, S
Liptzin, D
Griffin-LaHue, D
Topics
Soil Fertility and Soil Health Testing
Crop Nutrient Management
Organic Amendments, Cover Crops, and Soil Health
Nutrient Management of Agronomic Crops
Fertilizer Evaluations
4R's for N, P, K, S
Nutrient Cycling in Regenerative Agriculture
General
Environmental and Agricultural Nutrient Management
Type
Oral
Poster
Year
2021
2007
2009
2011
2013
2015
2017
2019
2023
Home » Authors » Results

Authors

Filter results79 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 health... P. Miller, C. Jones, C. Zabinski, K. D'agati, M. Housman, S. Tallman

2. Stacking and Intersecting Nutrient 4Rs and Using In-Season Canopy Health and Petiole Nitrate Analysis on Russet Burbank Potatoes

The 4Rs of nutrient management is a global outreach with an aim to improve the sustainability of major cropping systems and the environment. The objective for this project is to evaluate individual and stacked 4R management practices and how they intersect in Russet Burbank potato at a field near Grace, Idaho in 2020. Nitrogen (N) fertilizer treatments included all combinations of two sources [urea vs polymer coated urea (PCU)], two rates (207 vs. 247 kg ha-1), and two timing/placements... S. Stapley, B. Hopkins

3. Soil Health Changes Following Transition from an Annual Cropping to Perennial Management-Intensive Grazing Agroecosystem

Management-intensive Grazing (MiG) on irrigated, perennial pastures has steadily increased in the western US due to pressure for reducing public lands grazing, overall declining land available for pasture, and decreasing commodity prices. However, there are still many unknowns regarding MiG and its environmental impact, especially with regards to soil health. Over a two-year period, we studied changes in soil health under a full-scale, 82 ha pivot-irrigated perennial pasture system grazed with... J. Ippolito, C. Shawver, J. Brummer, J. Ahola, R. Rhoades

4. 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

5. Static Range Nitrogen Management in Northwest U.S. Sugarbeet Production

Nitrogen (N) management is important in sugarbeet production. This paper presents data to support a shift from a yield-based N management approach to a static range N management approach in the Northwest U.S. Production data and research show that yield-based N management can result in over application of N. Past research has been critical to improving and understanding sugarbeet N nutrition. However continued research is needed so cumulative data can be evaluated to improve management practices.... D. Bjorneberg, D. Tarkalson, D. Olsen

6. 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 optimizing... C. Rogers, G. Thurgood, B. Dari, J. Marshall, O.S. Walsh, K. Schroeder, G. Loomis

7. Effects of Semiarid Wheat Agriculture on Soil Microbial Properties: A Review

Agricultural management decisions on factors such as tillage, fertilization, and cropping system determine the fate of much of the world’s soils, and soil... J. Norton, H. Rodgers, L. Van diepen

8. Impact of Soil Health Practices in an Irrigated Agroecosystem

Regional farming practices in cold semiarid irrigated agroecosystems with short growing seasons are shifting to reduced tillage and overhead irrigation to stay economically viable, but more research is needed on the impact of soil health practices such as crop diversification, reduced tillage, and livestock integration on soil physical and chemical properties in these systems. A multi-year study from 2014-2020 in the Bighorn Basin of Northwest Wyoming used a three-crop rotation (diversification... T. Vance, V. Crowe, J. Norton

9. 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 word... B. Hopkins

10. Polymer Coated Urea and Urea Blends on Potato

Potato (Solanum tuberosum L.) is a globally important crop with significant economic and environmental impacts. Nitrogen (N) has a large impact in both instances. Polymer coated urea (PCU) is a N source with the ability of improving production and the environment. Environmentally Smart Nitrogen (ESN) is a PCU that may reduce the need for continual N application throughout the season. The objective of this research was to evaluate the impacts on potato tuber yield and quality with uncoated... E. Carlock, A. Weigel, T. Searle, T. Hopkins, J. Williams, B. Hopkins

11. Polymer Coated Urea Impact on Barley Yield and Protein

Polymer coated urea (PCU) is an enhanced efficiency nitrogen (N) fertilizer shown to regulate N release over a season benefiting production and reducing nutrient pollution. The purpose of this study was testing the effect of uncoated and coated urea blends on irrigated barley yield and protein. The study consisted of three N rates applied as all urea or a 50-50 blend of PCU and urea. As expected, N rates increased yields and protein. In general, urea resulted in increased yields with... S. Fahning, T. Searle, A. Weigel, R. Buck, T. Hopkins, B. Hopkins

12. Struvite Phosphorous Fertilizer on Sugar Beet

Sugar beet is very sensitive to P deficiency early in the growing season. Crystal Green is a struvite phosphorus (P) fertilizer source that may uniquely enhance uptake in sugar beet. In this study, we examine the effect of struvite applied to sugar beet and compare the results against the use of traditional monoammonium (MAP) fertilizer and a control. There was a significant increase in response to MAP over the control for both total and sugar yield. The struvite based fertilizer had an additional... J. Fisher, E. Woolley, J. Svedin, B. Hopkins

13. Water and Nitrogen Interactions in Kentucky Bluegrass

Pressure is increasing in arid regions to conserve water, especially during drought. Turfgrass is the irrigated crop of greatest acreage in the United States and is coming under scrutiny in urban ecosystems. The purpose of this study was evaluating water use by Kentucky bluegrass (​Poa pratensis​ L.) under various irrigation and nitrogen (N) regimes. A study was conducted in an established stand of Kentucky bluegrass in Provo, UT, USA. The turfgrass was split equally into 27 plots (11... A. Hopkins, C. Campbell, B. Hopkins, N. Hansen

14. Source and Rate Interactions for Enhanced Efficiency Phosphorus Fertilizers

Phosphorus (P) is an essential plant nutrient and plays a major role in the health and wellbeing of ecosystems. Deficient P is detrimental to plants. Excessive P is also detrimental to plants and is potentially harmful environmentally. Soil testing is an effective tool to help growers determine if fertilizer P is needed and, if so, the rate that is needed to be applied. Rates higher than the recommended amount can be detrimental to plant health and decrease yield. In addition to applying the right... A. Norris, B. Hopkins

15. Polymer Coated Urea in Kentucky Bluegrass

Nitrogen (N) is a commonly over-applied nutrient in urban environments. This over-application has led to nutrient pollution of the atmosphere and hydrosphere. The losses of N to the environment can be mitigated with the use of enhanced efficiency fertilizers, such as polymer coated urea (PCU). Some PCU labels state that a single annual application is a best management practice. The objective of this study was to evaluate a PCU compared to monthly applications of ammonium sulfate/urea.... S. Stapley, J. Buss, B. Hopkins

16. Phosphorus Fertilizer and Hydrogel for Rangeland Seeding

The US Air Force uses live munitions at Hill Air Force Base, a desert testing range west of Salt Lake City, Utah, USA. Resultant fire has disturbed rangeland vegetation. Revegetation of the area is impeded by low average precipitation rates of approximately 0.025 m per year, and opportunistic invasive species. Previous studies indicated hydrogel increases soil water content and the longevity of bottlebrush squirrel tail seedlings. In this glasshouse study, the effects... M. Valencia, S. Nelson, B. Hopkins

17. Struvite Phosphorus Fertilizer on Potato

Potato (Solanum tuberosum L.) is a staple in the global economy and on the dinner table. It has an unusually high demand for phosphorus (P) due to its shallow, inefficient root system. Most P fertilizers are water soluble, but then precipitate quickly—potentially resulting in poor plant uptake. Crystal Green (a struvite based fertilizer) is acid soluble, but not water soluble. In theory, it remains undissolved until plant roots exude acids— potentially avoiding the precipitation... R. Woolley, J. Svedin, E. Woolley, B. Hopkins

18. Boron Fertilization with Aspire® in Alfalfa and Potato

Potassium (K) and boron (B) are essential nutrients. The spatially even distribution of applying K fertilizer is typically not a problem, but for B fertilizer application, it is a problem. This is especially difficult for crops such as alfalfa (Medicago sativa L.) and potato (Solanum tuberosum L.) due to low B rate and limited soil exploration by roots. Fertilizer with K and B fused into a single granule could result in even distribution. Trials were performed to evaluate the performance... E. Woolley, T. Searle, T. Hopkins, J. Williams, B. Hopkins

19. New Hydroponic System for Testing Mineral Nutrient Deficiencies and its Application to Quinoa

Correlating plant tissue nutrient concentrations with visual symptoms is valuable in combating mineral nutrient deficiencies and toxicities. Major crops tend to have large amounts of information regarding nutrient concentrations and visual symptoms of deficiencies, but this information is often lacking for minor crops, including quinoa (Chenopodium quinoa L.) Because nutrient concentrations can be easily controlled, hydroponics effectively demonstrate isolated specific nutrient related symptoms.... D. Cole, R. Woolley, R. Buck, B. Hopkins

20. 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 the... C. Campbell, N. Hansen, B. Hopkins, S. Evans, E. Campbell, A. Campbell, L. Rivera, D. Cobos

21. 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 scarcity... B. Hopkins, N. Hansen

22. 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, effects... J. Ippolito, D. Bjorneberg, D. Stott, D. Karlen

23. 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 impacts... J. Svedin, N. Hansen, R. Kerry, R. Christensen, B. Hopkins

24. 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 improved... E. Shipp, T. Hopkins, B. Hopkins

25. 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 Kentucky... K. Russell, A. Hopkins, N. Hansen, B. Hopkins

26. 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-use... S. Bartholomew, T. Hopkins, B. Hopkins

27. 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 employed... S. Evans, N. Hansen, A. Blaylock

28. 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 included... C. Youngquist, J. Norton, J. Harsh

29. 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 and... A. Carroll, C. Lindsey, J. Baker, B. Hopkins, N. Hansen

30. 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

31. 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 50,... J. Buss, J. Gish, B. Hopkins

32. 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 the... B. Hopkins, J. Stark

33. 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 subsequent... C. Jones, P. Miller, S. Tallman, M. Housman, C. Zabinski, M. Burgess, J. O'dea, A. Bekkerman

34. 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 than... D. Bjorneberg, A. Koehn, J. Ippolito

35. 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 220... B. Hopkins, B. Black, B. Neville, C. Ewell, B. Geary

36. 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 pollution,... A.W. Pearce, J. Johns, D. Robinson, N. Hansen

37. 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

38. 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 hydrophobicity... B. Hopkins, K. Fernelius, M. Madsen, K. Russell, B. Roundy

39. 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 initial... B. Hopkins, C. Ransom, M. Ruth, T. Blair, L. Sutton, D. Bradshaw, K. Campbell

40. 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 (MAP)... B. Hopkins, T. Blair, J. Selman, C. Ransom, T. Hopkins

41. 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 they... J. G. davis, A. Sukor, C. Ramsey

42. 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 photoacoustic... B. Hopkins, J. Svedin, C. Ransom, J. Buss, T. Blair

43. 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 increases... B. Hopkins, T. Blair, M. Hill, C. Ransom

44. 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

45. 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 irrigated... J. Ippolito, D. Bjorneberg

46. 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 weighed... K. Mcvay, K. Kephart, Q. Khan

47. 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 applications... A. Moore, M. Satterwhite, J. Ippolito

48. 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 plant... B. Hopkins, C. Ransom, T. Taysom, J. Lemonte

49. 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 applied... B. Hopkins, L. Sutton, C. Ransom, T. Blair, J. Moody, K. Manning, S. Bergsten

50. 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 total... N. Andrews, D. Sullivan, J. Julian, K. Pool

51. 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 monoammonium... B. Hopkins, B. Webb, M. Hill, C. Ransom

52. 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 efficiency... B. Hopkins

53. 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 tropical... R. Lentz, J. Ippolito, K. Spokas, J. Novak, H. Collins, J. Sterubel

54. 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), calcium... A. Moore, B. Brown, J. Ippolito, S. Hines, M. De haro marti, C. Falen, M. Chahine, T. Fife, R. Norell

55. 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 these... B. Hopkins, C. Ransom

56. 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 Calculator... D. Sullivan, N. Andrews, R. Datta, K. Pool

57. 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 verdure... B. Hopkins, J. Lemonte, J. Summerhays, V. Jolley

58. 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 resistant... B. Hopkins, E. Buxton, V. Jolley, R. Christensen

59. 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

60. 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 separate... B. Hopkins, B. Webb, K. Marcroft, R. Christenson, V. Jolley

61. 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 go... J. Norton, E. Mukhwana

62. 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 as... B. Webb, B. Hopkins, M. Pletsch, D. Cook, M. Vickery, V. Jolley

63. 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 Zn... B. Webb, B. Hopkins, J. Ellsworth, S. Barben, B. Nichols, V. Jolley

64. 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 thorough... J. G. davis, A. Elliott, N. Marcillac, J. Pritchett, C. Stewart, A. Mink

65. 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

66. 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 at... B. Webb, B. Hopkins, J. Ellsworth, V. Jolley, R. Callahan

67. Reducing Dairy Effluent Phosphorus Content Through Struvite Production

Forced precipitation of struvite (magnesium ammonium phosphate hexahydrate, MgNH4PO4ď‚·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 existing... J. G. davis, J. Ippolito, M. Massey, R. Sheffield

68. 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 with... J. Norton

69. 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 (Fecal... R. Yost, R. Pattnaik, G. Porter

70. 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 polymer-coated... B. Hopkins, T. Taysom, A. Shiffler, S. Stephens

71. 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 grasses—... R. Valencia-gica, R. Yost, G. Porter, R. Pattnaik

72. 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) and... J.A. Burke, K.L. Lewis

73. 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 Valley... D. Sullivan, N. Andrews

74. Using Calcium Hydroxide for Lime Incubation Studies and Moisture Effects on Liming

Plant health and productivity are negatively affected by soil acidity. Soil physical properties such as soil texture, soil organic matter, and nutrient content help soils resist changes in their acidity (buffering capacity). Soils have different buffering capacities; agricultural producers need to know how responsive a soil is to lime and how much lime is required to modify a soil to a certain pH (lime requirement). One method to evaluate soil liming requirements and buffering capacity is to add... C. Collins, E. Loera, R. Reid, J. Spackman

75. Polymer Coated Urea: Microplastics in the Urban Landscape

Polymer Coated Urea (PCU) in urban landscapes has recently become a controversial practice as some fear the repercussions of the polymer coatings left behind in soils and the environment to potentially be detrimental to land and water ecosystem health. The use of PCU has been beneficial in effectively supplying nitrogen (N) to plants with less leaching, denitrification, and volatilization losses to the environment. However, the pollution of microplastics may outweigh these benefits. The purpose... C. Seely , B. Hopkins

76. A Single Nutrient Source Hydroponic Solution: pH Buffering

MES (2-[N-morpholino]ethanesulfonic acid) is a biological buffer that can be used to stabilize pH in a hydroponic system. It can, however, be toxic to plants, including soybeans. Hydroponic systems are efficient for studying plant nutrition. It is often desirable to adjust individual nutrients for unique species’ needs and/or to create multiple nutrient deficiencies within the same study. However, this is challenging to do with traditional solutions as nutrients are generally... J.D. Ioannou, B. Hopkins

77. Nitrogen Management to Increase Cotton Production in Conservation Cropping Systems

The use of conservation management practices, like cover crops and no-tillage, is common in semi-arid cropping systems to reduce wind erosion. However, the use of these practices can also reduce cotton lint yield. The purpose of this study was to determine the impact of nitrogen (N) management in conservation cropping systems to increase cotton lint yield. Two experiments were conducted at the Agricultural Complex for Advanced Research and Extension Systems in Lamesa, TX, USA. The first experiment... J.A. Burke, K.L. Lewis, J.L. Foster-malone

78. 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, variable... E.A. Flint, M. Yost, B. Hopkins

79. 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, biological... M. Desjardins, A. Bary, J. Ippolito, S. Cappellazzi, D. Liptzin, D. Griffin-lahue