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Fife, T
Falen, C
Hammermeister, E
Israelsen, C
Buxton, E
Wildfong, D
Barben, S
Buck, R
Zhu-Barker, X
Okorie, B
Bremer, E
Foster, M.J
Hergert, G
Beck, D
Wood, B
Westfall, D
Hines, S
Olsen, S
Wiebe, J
Heidenreich, D.T
Habteselassie, M
O'Geen, T
Hicks, D
Heinrich, A
Hutmacher, R
Wang, G
Zumbrunnen, J
Hillmer, R
Hopkins, B.G
Bush, T.V
Weisshaar, E.M
Walsh, O
Fahning, S.R
Fernandez, F.G
Black, B
Black, B
Harrison, J
Bloedel, D
Wilson, T
Winchester, A
Ioannou, J.D
Hosford, P
Hopkins, B
Foster-Malone, J.L
Hortin, J
Barnhill, J
Add filter to result:
Authors
Greer, K
Wiebe, J
Bremer, E
Fernandez, F.G
Spackman, J.A
Bremer, E
Cole, D.L
Heidenreich, D.T
Stapley, S.H
Lambert, A.M
Buck, R.L
Hopkins, B.G
Deakin, J.W
Potter, M
Cartwright, A
Hortin, J
Sparks, D
McLean, J.E
Britt, D.W
Anderson, A.J
Jacobson, A.R
Jeliazkova, E
Moore, A
Spring, J
Wilson, T
Weisshaar, E.M
Geary, B.T
Fahning, S.R
Hopkins, B.G
Stapley, S
Hopkins, B
Norberg, S
Fransen, S
Harrison, J
Llewellyn, D
Whitefield, L
Yi, Q
Horwath, W
Haas, S
Zhu-Barker, X
Zapata, D
Zhu-Barker, X
Steenwerth, K
Horwath, W
Bush, T.V
Crowe, V
Norton, J
Webb, B
Hopkins, B
Ellsworth, J
Barben, S
Nichols, B
Jolley, V
Hopkins, B
Stephens, S
Shiffler, A
Webb, B
Hopkins, B
Ellsworth, J
Jolley, V
Callahan, R
Norton, J
Habteselassie, M
Stark, J
Miller, B
Reese, C
Clay, D
Beck, D
Englund, R
G. Davis, J
Schierer, R
Zumbrunnen, J
Hopkins, B
Taysom, T
Shiffler, A
Stephens, S
Walworth, J
Pond, A
Nunez, H
Wood, B
Kilby, M
Westfall, D
Khosla, R
Shaver, T
Hopkins, B
Buxton, E
Jolley, V
Christensen, R
Cardon, G
Barnhill, J
Pace, M
Israelsen, C
Miner, D
Greenhalgh, L
Banks, S
Shao, M
Rothlisberger, D
Olsen, S
Hole, P
Khosla, R
Westfall, D
Frasier, W
Koch, B
Webb, B
Hopkins, B
LeMonte, J
Taysom, T
Jolley, V
Hopkins, B
Webb, B
Marcroft, K
Christenson, R
Jolley, V
Webb, B
Hopkins, B
Pletsch, M
Cook, D
Vickery, M
Jolley, V
Hopkins, B
Webb, B
Hill, M
Ransom, C
Hopkins, B
Moore, A
Brown, B
Ippolito, J
Hines, S
de Haro Marti, M
Falen, C
Chahine, M
Fife, T
Norell, R
Pettygrove, S
O'Geen, T
Southard, R
Hopkins, B
Ransom, C
Hopkins, B
leMonte, J
Summerhays, J
Jolley, V
Greer, K
Wildfong, D
Hicks, D
Hammermeister, E
Hopkins, B
Blair, T
Hill, M
Ransom, C
Bronson, K
Mon, J
Hunsaker, D
Wang, G
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
Hopkins, B
Black, B
Neville, B
Ewell, C
Geary, B
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
Hopkins, B
Svedin, J
Ransom, C
Buss, J
Blair, T
Walsh, O
Pandey, A
Christiaens, R
Walsh, O
Pandey, A
Christiaens, R
Walsh, O
Pandey, A
Christiaens, R
Walsh, O
Pandey, A
Christiaens, R
Campbell, C
Hansen, N
Hopkins, B
Evans, S
Campbell, E
Campbell, A
Rivera, L
Cobos, D
Hopkins, B
Hansen, N
Bremer, E
Shapiro, C
Ferguson, R
Wortmann, C
Shaver, T
Krienke, B
Hergert, G
Maharjan, B
Greer, K
Bremer, E
Sievers, T
Heinrich, A
Sullivan, D
Flynn, R
Walworth, J
Davenport, J
Ulery, A
Bloedel, D
Gleason, J
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
Walsh, O
Marshall, J
McClintick-Chess, J
Blanscet, S
Jackson, C
Walsh, O
McClintick-Chess, J
Blanscet, S
Walsh, O
Torrion, J
Liang, X
McClintick, J
Blanscet, S
Hillmer, R
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
Hutmacher, R
Clark, N
Dahlberg, J
Angeles, J
Norberg, S
Mackey, E
Fransen, S
Harrison, J
Llewellyn, D
Whitefield, L
Norberg, S
Llewellyn, D
Driver, J.P
Fransen, S
Harrison, J
Hopkins, B.G
Bremer, E
Madsen, I
Greer, K
Stapley, S.H
Whitaker, C.C
Hansen, N.C
Christensen, R.C
Jensen, R.R
Yost, M.A
Hopkins, B.G
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
Spackman, J
Walsh, O
Adjesiwor, A
Adeyemi, O
Sagers, J
Findlay, R
Bevan, J
Okorie, B
Yost, M
Deep, K
Howard , N
Deep, K
Yost, M
Williams, J
Hopkins, B
Cardon, G
Black, B
Hopkins, B
Foster, M.J
Nelson, S.V
Sannar, R.E
Bremer, E
Greer, K
Hopkins, B
Topics
Recycled and Repurposed Nutrient Sources
Fertilizer Evaluations
Crop Nutrient Management
Manure and Compost Management
Nutrient Management of Agronomic Crops
Nutrient Management of Horticultural Crops
Organic Amendments, Cover Crops, and Soil Health
4R's for N, P, K, S
Nutrient Cycling in Regenerative Agriculture
Environmental and Agricultural Nutrient Management
Student Posters
Type
Oral
Poster
Year
2021
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2009
2011
2013
2015
2017
2019
2023
2025
Home » Authors » Results

Authors

Filter results94 paper(s) found.

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

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

2. 15Nitrogen Uptake and Use Efficiency in Corn in Response to Fertilizer Rate and Timing

Urea fertilizer applications at planting are becoming increasingly common for U.S. upper Midwest corn (Zea mays L.) production but wet spring conditions may result in significant nitrogen (N) fertilizer loss. Split-applications may avoid wet conditions and improve fertilizer uptake and use efficiency. Six field studies were performed to determine the effect of urea fertilizer rate and application timing on fertilizer-derived N (FDN) and soil-derived N (SDN) plant uptake over two consecutive... F. Fernandez, J. Spackman

3. Factors Influencing Efficacy of Elemental Sulphur Fertilizers

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

4. New Hydroponic System for Testing Mineral Nutrient Deficiencies: Quinoa

Correlating plant tissue nutrient concentrations with visual symptoms is valuable in combating mineral nutrient deficiencies and toxicities. Major crops tend to have adequate information regarding nutrient concentrations and visual symptoms of deficiencies, but this 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. However,... D.L. Cole, D.T. Heidenreich, S.H. Stapley, A.M. Lambert, R.L. Buck, B.G. Hopkins

5. Is Mitigation of Drought Stress By Zinc Oxide Nanoparticles Driven By a Nano-Specific Mechanism or Alleviation of Micronutrient Deficiency?

It has been reported that zinc oxide (ZnO) nanoparticles (NPs) can promote drought tolerance in crops when used as soil amendments. However, many of these experiments were conducted in Zn-deficient growth media with no comparison to currently available Zn fertilization methods, making it unclear if the benefits from adding ZnO NPs were caused by a nano-specifc mechanism or simply by the mitigation of a micronutrient deficiency. A review of the literature shows that of 12 published experiments... J.W. Deakin, M. Potter, A. Cartwright, J. Hortin, D. Sparks, J.E. Mclean, D.W. Britt, A.J. Anderson, A.R. Jacobson, L. Yen

6. Evaluating Nutrient Uptake and Partitioning for Hybrid Carrot Seed Production in Central Oregon

Hybrid carrot seed production is prominent in Central Oregon, however plant nutrient uptake dynamics in this crop are not well understood. The aim of this research was to evaluate nutrient uptake and partitioning during the production cycle of a modern Nantes-type hybrid carrot. Trials were conducted in two commercial carrot seed production fields planted to ‘Nantes 969’. Below- and above-ground plant biomass was destructively sampled and separated into roots, tops, and umbels throughout... E. Jeliazkova, A. Moore, J. Spring, T. Wilson

7. Denitrifying Woodchip Bioreactor Performance in the Pacific Northwest

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

8. Enhanced Efficiency Nitrogen Fertilizer: Coated Urea

Nitrogen is the most common fertilizer applied to crops, as it is typically the limiting nutrient in plants. However, about half of the nitrogen added to soil as fertilizer is either emitted to the atmosphere as ammonia, nitrous oxide or other gaseous forms, or finds its way into surface or ground waters as nitrate (Kibblewhite, 2007). The inefficient use of fertilizers depletes natural resources, and increases atmospheric emissions and environmental pollutants. With the use of enhanced efficiency... B. Geary, S.R. Fahning, B.G. Hopkins

9. 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

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

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

11. Compost Application in California Tomato Cropping Systems

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

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

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

13. 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

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

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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. Evaluation of Nitrogen Fertilization and Drip Irrigation Levels on Yields of San Joaquin Valley, California, Forage Corn and Sorghum Cultivars

In 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 improve... R. Hutmacher, N. Clark, J. Dahlberg, J. Angeles

27. Developing Practical Phosphorus and Potassium Tissue Test Recommendations and Utilizing Struvite in Modern Alfalfa Systems

Tissue 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

28. 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

29. 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

30. Nutrient Lessons from Long-term Cropping System Studies

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

31. Nebraska Nitrogen Management Present and Future

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

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

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

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

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

34. Digital Tools to Improve Sustainable Agriculture Practices

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

35. 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

36. 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

37. 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

38. 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

39. Precision Sensing for Improved Wheat Production

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

40. Plant Available Silicon Application in Winter Wheat

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

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

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

42. 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

43. 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

44. 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

45. 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

46. 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

47. 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

48. 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

49. 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

50. 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

51. 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

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

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

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

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

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

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

55. Liquid N Fertilizer Evaluation in Spring Wheat

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

56. 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

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

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

58. 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

59. 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

60. 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

61. 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

62. 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

63. K Fixation and Significance for Crop Production

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

64. 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

65. 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

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

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

67. 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

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

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

69. Economics of Fertilization Under Site-specific Management Zones

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

70. 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

71. 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

72. 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

73. 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

74. 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

75. 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

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

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

77. Is Protein Enough for Assessing Wheat Flour Quality?

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

78. Predicting Phosphorus Runoff from Calcareous Soils

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

79. 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

80. Soil Zinc Application for Southwestern Pecan

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

81. Remote Sensing of Corn N Status with Active Sensors

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

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

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

83. Variable Rate Fertilization: Soil Moisture Impacts

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

84. Development of a Constrained Resource Model to Support Intercropping Decisions

Crop producers are interested in intercropping due to its’ potential to increase profitability, yield stability and sustainability. Our objective was to extend a simulation model to forecast crop yields (PRS® CropCaster®) to pulse-oilseed intercrops.  This tool would provide crop producers with forecasts of yields of each crop component under different management and environmental conditions. Based on competition for fertilizer 15N... E. Bremer, I. Madsen, K. Greer

85. Stacking 4R Nutrient Management: Potato

The 4Rs of nutrient management are research-based guidelines with the aim to improve the sustainability of major cropping systems and the environment without compromising crop yield and quality. The term “4R” represents fertilizer applied at the Right rate with the Right source, Right timing, and Right placement. The objective of this project is to evaluate the interactions of individual and combined 4R management practices. In 2020, potato (Solanum tuberosum L.) was grown... S.H. Stapley, C.C. Whitaker, N.C. Hansen, R.C. Christensen, R.R. Jensen, M.A. Yost, B.G. Hopkins

86. 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

87. 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

88. 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

89. 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

90. Nitrogen Fertilizer Rate and Timing Implications for Malt, Food, and Feed Barley Production in Southern Idaho

Nitrogen is an essential nutrient required to produce high-yielding barley. Nitrogen strongly impacts barley yield, grain protein, tillering, and lodging potential. Unlike other crops such as corn, available nitrogen must be carefully managed for producers to achieve both optimal yield and grain quality for malt, food, and feed barley. Exessive nitrogen availability increases grain protein concentration that may be unsuitable for malting but may be ideal for feed or food barley. The objective... J. Spackman, O. Walsh, A. Adjesiwor, O. Adeyemi, J. Sagers, R. Findlay, J. Bevan

91. 4R Nitrogen Management Effects on Silage Corn Production

The 4R nutrient stewardship framework aims to improve fertilizer management through four core principles: right source, rate, time, and place. Nitrogen is one of the most important and costly inputs for silage corn production. Excessive or inefficient N applications rapidly decrease profits for growers and can cause environmental concerns. Nitrogen loss can occur through leaching, runoff, and denitrification. Most previous studies evaluating N management for silage corn have only examined one... B. Okorie, M. Yost, K. Deep, N. Howard

92. Effect of 4R Nitrogen Management on Residual Soil Nitrate and Soil Health

Nitrogen is one of the most important and expensive inputs for forage, grain, vegetable, and fruit crops. Excessive fertilizer reduces profit for farmers and can cause environmental harm. Nitrate leaching is the main factor contributing to rising nitrate levels in groundwater, leading to water quality degradation. The 4R nutrient stewardship framework aims to optimize fertilizer management. The Right rate matches the amount of fertilizer to the crop needs, the Right source matches fertilizer type... K. Deep, M. Yost, J. Williams, B. Hopkins, G. Cardon, B. Black

93. Banana Fiber as a Soil Amendment in Potato and Corn

Banana (Musa spp. L.) pseudostem fiber has unique properties that may prove helpful in plant and soil management, including a high water holding capacity. Increased capacity could be useful in water conservation efforts in areas experiencing long-term drought. In the agricultural space, banana fiber could be used to maintain soil moisture, thus lowering the frequency and/or amount of irrigation. The objectives of irrigated field studies in Provo, UT, USA were to measure the impact of... B. Hopkins, M.J. Foster, S.V. Nelson

94. Recovered Carbon Black from Pyrolyzed Tires as a Zinc Fertilizer for Field Corn in Calcareous Soils

Waste tires exist in immense quantities, representing a substantial pollution source containing a variety of environmentally concerning components, including the heavy metal zinc (Zn) added as Zn oxide (ZnO) during tire manufacture. Pyrolysis under high vacuum is a potential disposal solution. One of the by-products of this process is recovered Carbon Black (CB) that is enriched in Zn, an essential plant nutrient. Our objective was to determine if recovered CB from can serve as a fertilizer Zn... R.E. Sannar, E. Bremer, K. Greer, B. Hopkins