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1. A Science-based Approach to Trialing Biostimulants and Interpreting Trial DataWhether 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 |
2. Accumulation and Partitioning of Nutrients by Irrigated Sugar Beets During the Growing Season in Southern IdahoAmounts 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 |
3. Adopting Quinoa in Eastern Idaho – An Investigation of Agronomic PracticesQuinoa 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 |
4. Aggregate Size, C, N and P Dynamics in Different Dryland Organic Wheat SoilsUtah is one of the largest producers of dryland organic wheat in the US. Previous research indicates that a single application of compost can mitigate low and variable yields and improve soil properties over the long-term. Compost carryover is thought to be greater in high pH and highly calcareous soils compared with neutral, low calcareous soils. However, the mechanisms responsible are unclear. We evaluated the effect of a one-time compost addition on the formation, stability and carbon... I. Atoloye |
5. Amending Acidic Soils for Sustainable Wheat ProductionSoils 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 |
6. Application of Ion Exchange Resin Membranes to Nitrate Testing in the WestResin 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 |
7. Approaches to Nutrient RecommendationsScientific 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 |
8. Belowground Ecological Interactions For Improved Plant Health, Nutrition And Environmental Quality In Agricultural ProductionPlant 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 |
9. Biological and Chemical Drivers of Nutrient Dynamics in the Rhizosphere: Applications for Crop ManagementThe 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 |
10. Boron Fertilization with Aspire® in Alfalfa and PotatoPotassium (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 perfor... E. Woolley, T. Searle, T. Hopkins, J. Williams, B. Hopkins |
11. 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 |
12. Canola Roots of Water and Nitrogen Use Efficiency: New Lessons for PNW Wheat GrowersThe 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 |
13. Cover Crops As A Source Of Plant-Available Nitrogen: Effect Of Residual Soil N And Cover Crop SpeciesFall-planted brassica and small grain cover crops have the potential to serve as catch crops by taking up residual soil nitrogen (N) in the soil. While plant species is often considered when estimating N release rates from cover crop residues, variation in residual soil N is rarely considered. The first objective of this study was to quantify the effect of N fertilizer application rate (to simulate varying residual soil N levels) on tissue N concentrations of several cover... J. Neuman, D. Sullivan, A. Moore |
14. Cover Crops for Hop Production in Semi-arid ClimatesTilling 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 |
15. Creating Prescription Variable Rate Irrigation and Fertilization Zones: Water and Nutrient Management InteractionsVariable 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 |
16. Crop Genetic Variability for Nutrient Use Efficiency: Biological Foundation, and Case of Spring WheatRecent 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 |
17. Developing a Soil Test Kit for Extension ProgrammingSoil 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 |
18. Developing Practical Phosphorus and Potassium Tissue Test Recommendations and Utilizing Struvite in Modern Alfalfa SystemsTissue testing whole alfalfa plants at harvest provides opportunities to direct nutrient decision making more accurately. Critical levels developed allow in- season recommendations and applications and would save producers time and effort since growers are already taking samples for hay quality. Three experiments were designed including: P Study with differing rates of P2O5 using monoammonium phosphate (MAP); including: 0, 30, 60, 120, 240 lbs./acre on an 8.1 ppm P soil (Olson P method);... S. Norberg, E. Mackey, S. Fransen, J. Harrison, D. Llewellyn, L. Whitefield |
19. Digital Tools to Improve Sustainable Agriculture PracticesVisualizations 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 |
20. 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 |
21. Dry Bean Production in CaliforniaThere are four species and eight market classes of dry beans grown in California. These include lima beans (baby and large, Phaseolus lunatus), common beans (kidney, pink, white, cranberry, black turtle, P. vulgaris), blackeye (cowpea, Vigna unguiculata), and garbanzo beans (chickpea, Cicer arietinum). Dry beans are an important specialty market for California. In 2017, growers harvested 50,000 acres of dry beans valued at $60 million. Lima beans accounted for ab... R. Long |
22. Effect of Cover Crops and Compost on Soil Water Availability in Organic Dryland WheatIn 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 |
23. Effect of Management on Nitrogen Budgets and Implications for Air, Soil, and Water QualityNitrogen 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 |
24. Effects of a One-time Compost Addition on Soil Health in a Rainfed Dryland Organic Wheat SystemMaintaining 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 |
25. Estimating Non-Fertilizer Nitrogen ContributionsCalifornia 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 |
26. Evaluating and Revising Guidelines for Blueberry Tissue Nutrient Standards in WashingtonLeaf 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 |
27. Evaluation of Nitrogen Fertilization and Drip Irrigation Levels on Yields of San Joaquin Valley, California, Forage Corn and Sorghum CultivarsIn California (CA), approximately 500,000 acres of corn are grown annually, with most grown for dairy forage. Under reduced irrigation water (IW) supply conditions, forage sorghum acreage can increase to 90,000 acres annually. Corn nitrogen (N) demand is well documented in studies conducted outside of CA, but little research on forage corn and sorghum N use efficiency (NUE) under varying levels of IW has been conducted. With such a large statewide acreage, it is important to ... R. Hutmacher, N. Clark, J. Dahlberg, J. Angeles |
28. Evaluation of Soil Tests for Potentially Mineralizable Soil Nitrogen in Snake River Plain Soils in IdahoSoil 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 |
29. Evolution and Utilization of the Smaf for Soil Health AssessmentsSoil 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 |
30. Fine Tuning Nitrogen Management Soil TestsRecent 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 |
31. Groundwater Protection in California: Nitrogen Planning and ReportingConcern 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 |
32. Humic Products in Agriculture: Potential Benefits and Research ChallengesHumic 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 |
33. Improving Nitrogen Use Efficiency of Cool Season Vegetable Production Systems with Broccoli RotationsNitrate 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 |
34. Improving Nutrient Use Efficiency in Irrigated Areas of Western AgricultureMuch 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 |
35. Improving Phosphorus Use Efficiency: Right Rate, Timing, and Placement and Enhanced Efficiency Fertilizer Sources: Research SummaryPhosphorus (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 |
36. Integrating Cover Crops and Livestock into Irrigated Cropping SystemsIntensive annual cropping consisting of barley-sugar beet rotations in irrigated systems could benefit from integration of cover crops and livestock. This research is being conducted on the University of Wyoming Research Station in Powell, WY, and on six farms in the surrounding area. This area has a short growing season and integrating cover crops into the cropping system is difficult. This study examines the implementation of cover crops after mid-summer barley harvest a... T. Bush |
37. Interagency Cooperation to Improve Nitrogen Management for Water Quality ProtectionAgriculture 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 |
38. Interpreting Compost AnalysesThis outreach publication is designed for wholesale buyers of compost for resale, nursery managers, public/private landscape managers, farm advisors, and farmers. The publication provides guidance on how to select a laboratory, based on intended compost end use (field application vs. potting soil). Interpretations are provided for laboratory tests available from commercial laboratories, including chemical tests (pH, soluble salt, macro- and micro-nutrients), physical ... D. Sullivan |
39. Irrigated Cereal Response to Nitrogen Applications to Improve Efficiencies for Yield and ProteinHigh 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 |
40. Irrigation Effects on N AvailabilityIrrigation 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 |
41. 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 |
42. Measuring Ammonia Loss Using Field-scale and Laboratory TechniquesFollowing 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 |
43. N Management Tools for Desert VegetablesOver 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 |
44. Nebraska Nitrogen Management Present and FutureUniversity 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 |
45. New Hydroponic System for Testing Mineral Nutrient Deficiencies and its Application to QuinoaCorrelating 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 s... D. Cole, R. Woolley, R. Buck, B. Hopkins |
46. Nitrogen and Irrigation Water Interactions in Drought Stressed Kentucky BluegrassThere 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 |
47. Nitrogen and Water Interactions: Crop Production Systems Case StudiesFarmers 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 |
48. Nitrogen Availability and Use Efficiency in Corn Treated with Contrasting Nitrogen SourcesNitrogen (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 |
49. Nitrogen Budgeting for Tree CropsIn 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 |
50. Nitrogen Management and Water Productivity of Grain Crops Under Drought or Limited IrrigationThe 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 |
51. Nitrogen Management in Small Grains After AlfalfaSmall grains are commonly grown following alfalfa in Utah and the Intermountain West, especially during drought years as small grains require less irrigation than corn. Several studies across the country have shown that corn following alfalfa rarely needs N fertilizer, yet relatively few have evaluated the N needs of small grains. Furthermore, research on the N needs of small grains grown as forage vs. grain are even more sparse. The objectives of this research are to quantify ... C. Pound, M. Yost, E. Creech, G. Cardon, K. Russell, D. Despain, J. Gale, K. Heaton, B. Kitchen, M. Pace, S. Price, C. Reid, M. Palmer, M. Nelson |
52. Nitrogen Mineralization of Dairy Manure in a Calcareous Soil Under Field ConditionsUnderstanding 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 |
53. Nitrous Oxide Emissions: Assessment and Mitigation in Irrigated Cotton in the Western USANitrogen 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 |
54. Nutrient Lessons from Long-term Cropping System StudiesThe 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 |
55. Nutrient Management and Improved Efficiency of Drip Irrigated Processing PotatoesWater 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 |
56. Nutrient Management in a Regulated EnvironmentLaws 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 |
57. Nutrient Management in Asian Leafy VegetablesAsian 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 |
58. Overview of the Efficacy of BiostimulantsSo-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 |
59. Paying Attention to Root Traits for the Effective Use of Water and NutrientsRoots 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 |
60. Pecan Rootstock Genotype Effects on Micronutrient Uptake in Alkaline, Calcareous SoilsAlkaline pH and lime content of soils in arid or semi-arid production regions often result in severe micronutrient deficiencies in pecan (Carya illinoinensis). Producers routinely manage micronutrients, especially zinc, through repeated foliar fertilizer sprays. Nevertheless, limited phloem mobility of micronutrients creates some challenges with this practice in pecan, including difficulty achieving adequate canopy spray coverage (e.g., due to large tree size or prolonged ... R. Heerema |
61. Phosphorus Efficiencies of Liquid P Fertilizers as Evidenced by P Adsorption Isotherms of Western Calcareous SoilsThe 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 |
62. Phosphorus Fertilizer and Hydrogel for Rangeland SeedingThe 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 |
63. Phosphorus Rate Effects with and without AVAIL on Dryland Winter Wheat in an Eroded Calcareous SoilSoluble phosphorus fertilizer precipitates rapidly after application on alkaline, calcareous soils. A fertilizer additive known as AVAIL® (J.R. Simplot Company) is purported to keep applied phosphorus fertilizer more available to plants by binding soil cations, thereby reducing precipitation reactions. In a soil high in base cations, this could prove useful due to the attraction of AVAIL® with cations such as Ca2+, but is fairly unstudied for dryland wheat production on... R. Hodges |
64. Plant Available Silicon Application in Winter WheatMany 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 |
65. Polymer Coated Urea and Urea Blends on PotatoPotato (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 uncoate... E. Carlock, A. Weigel, T. Searle, T. Hopkins, J. Williams, B. Hopkins |
66. Polymer Coated Urea Impact on Barley Yield and ProteinPolymer 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 wit... S. Fahning, T. Searle, A. Weigel, R. Buck, T. Hopkins, B. Hopkins |
67. Polymer Coated Urea in Kentucky BluegrassNitrogen (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 sulfat... S. Stapley, J. Buss, B. Hopkins |
68. Polymer Coated Urea: Meeting Plant Needs While Mitigating Environmental Impacts — Research SummaryFertile 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 |
69. Precision Sensing for Improved Wheat ProductionImproving 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 |
70. Preliminary Assessment of the Solvita-CO2 Test in Characterizing Management Effects on Soil Biological Activity in Some Soils of HawaiiThe 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 |
71. Response of Spring Wheat to Varied Nitrogen and Water ApplicationsThis 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 |
72. Science and Stakeholder Engagement on 4R Nutrient Stewardship, Sustainability and Nutrient Performance Indicators: a Recent Central to Eastern U.S. and Global PerspectiveFarmers 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 |
73. Soil Acidification: Identification, Prevention, Adaptation and RestorationLow 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 |
74. Soil Biological Indicators of Soil Health for Soil Health AssessmentsSoil 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 |
75. Soil Diversity and Agricultural Adaptation Across MicronesiaMicronesia, 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 |
76. Soil Management Assessment Framework Use for Identifying Soil Quality Changes in Irrigated AgricultureThe 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 |
77. Soil SodicitySoil 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 |
78. Soil Water and Plant Canopy Sensor Technologies to Optimize Water and Nutrient UseIn 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 |
79. Source and Rate Interactions for Enhanced Efficiency Phosphorus FertilizersPhosphorus (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 ... A. Norris, B. Hopkins |
80. Struvite Phosphorous Fertilizer on Sugar BeetSugar 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 addit... J. Fisher, E. Woolley, J. Svedin, B. Hopkins |
81. Struvite Phosphorus Fertilizer on PotatoPotato (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 precipitat... R. Woolley, J. Svedin, E. Woolley, B. Hopkins |
82. Sustaining Agriculture and the Environment Through Healthy SoilsSoil 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 |
83. Test Driving a New Nrcs Nutrient Budget Calculator for Nutrient Management Planning in CaliforniaIn 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 |
84. 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 |
85. Use of Biological Soil Tests to Assess Soil Health and ProductivityCrops 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 |
86. Utilizing the 4Rs to Mitigate Ammonia Toxicity in RootsThe 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 |
87. Wastewater Reuse in the Arid West: Increased Water Supplies and New Paradigms for Nutrient ManagementIrrigated 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 |
88. Water and Nitrogen Interactions in Kentucky BluegrassPressure 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 (1... A. Hopkins, C. Campbell, B. Hopkins, N. Hansen |
89. Winning the Battle Against Environmental Stress by Better Understanding Biostimulant ResponsesBiostimulants 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 |