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1. 4R Nitrogen Management Effects on Silage Corn ProductionThe 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 |
2. A Classification System for Assessing Applied N Performance in Dryland Wheat Crops of the Inland PNWWheat crops in the inland Pacific Northwest demand nitrogen (N) fertilizers at high levels to achieve yield and grain protein objectives. Inefficiencies in N use can accelerate soil acidification, contribute to N2O emissions and result in unnecessary input costs. More precise applications, using wheat performance maps at the field-scale, could lead to increased N use efficiency but requires a multidimensional assessment of performance including grain protein, yield, and N effic... D. Huggins, J. Casanova, C. Phillips |
3. Agronomic and Economic Comparison of Conventional and Direct-seeding in the Intermediate Rainfall ZoneThe predominant dryland cropping system in the low (<12 inch) and intermediate (12- 18 inch) rainfall areas of the Pacific Northwest (PNW) is winter wheat (Triticum aestivum L.) summer-fallow using conventional tillage. Tillage increases the rate of soil organic matter oxidation which has an adverse effect on soil physical, biological and chemical properties. A field experiment comparing conventional tillage-based summer- fallow with chemical summer-fallow and direct-seeding ... S. Petrie, S. Albrecht, D. Long |
4. Agronomic Biosolids Application Rates for Dryland Wheat Across a Range of Northwest Climate ZonesPredicting agronomic rates is important to derive optimum economic and environmental benefits from biosolids fertilizer applications. We conducted this research to 1) evaluate dryland wheat response to biosolids applications over a range of climate zones in the Pacific Northwest and 2) compare agronomic application rates predicted from yield curves with those predicted from published extension guidance. We applied a range of biosolids rates during the fallow year in ten on-farm dryland wheat ... A. Bary, D. Sullivan, C. Cogger |
5. Ammonia Recovery from Anaerobically Digested Dairy Wastewater Facilitated by In-situ Acid and Base Generation in a Transmembrane Electro-chemisorption SystemNitrogen (N) is essential for living organisms and is a critical element in agricultural production. Ammonia (NH₃), a vital component in the nitrogen cycle, can be produced naturally by nitrogen-fixing bacteria or artificially through the energy-intensive Haber-Bosch process. Anaerobically digested dairy wastewater (ADDW) could contain high concentrations of ammonia nitrogen (NH3-N) due to the conversion of organic N into NH3-N during the anaerobic digestion process. A... A.K. Das, L. Chen |
6. Ammonia Volatilization from Surface-applied Dairy Manure Anaerobic DigestateAnaerobic digesters are becoming increasingly common in the dairy industry as a more environmentally sustainable method to manage manure. However, the impact of the anaerobic digestion process on manure ammonium (NH4-N) composition and ammonia (NH3) volatilization potential are not well understood. The objectives of this study were to compare NH4-N concentrations and cumulative loss of NH3 by volatilization between influent, or raw manure, and ... C. Butler, A. Moore, S.B. Kulesza |
7. Application Timing, Soil Type, and Source Effects on Elemental S AvailabilityThe reduction in acid rain due to increased regulation of manufacturers in the U.S. has led to S deficiencies in agricultural crops. In response, elemental sulfur (S) fertilizer products are becoming more widely available to growers, but have not been evaluated for their S availability and S oxidation characteristics. The objective of our research was to evaluate the S availability and S oxidation rates of five elemental S fertilizer products. The evaluation was done using two Oregon soil typ... A. Cox, A. Moore |
8. Banana Fiber as a Soil Amendment in Potato and CornBanana (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 |
9. Best Management Practices (Bmps) for Ammonia Emissions Reduction from Animal Feeding Operations: a Colorado Case StudyAmmonia emissions from agriculture are a growing concern, in particular, in Colorado where nitrogen deposition in Rocky Mountain National Park has highlighted public concerns. Due to the high level of political pressure on agriculture to reduce its emissions, the agricultural community in Colorado has recently developed a Rocky Mountain National Park Ag Strategy for decreasing ammonia emissions from agriculture and nitrogen deposition in the park. The strategy includes the completion of a tho... J. G. davis, A. Elliott, N. Marcillac, J. Pritchett, C. Stewart, A. Mink |
10. Boron Fertilization in PotatoThe high value of potato (Solanum tuberosum L.), its inefficient rooting system and the low organic matter content of sandy soils on which potatoes are cultivated result in widespread application of boron (B) and other micronutrients. However, in times of cost trimming, B may become an omitted input regardless of soil test values. Further, soil tests for B may need to be updated for higher yields, better management or improved soil test methods. Russet Burbank potato was grown a... B. Webb, B. Hopkins, J. Ellsworth, V. Jolley, R. Callahan |
11. Collaborative Water Quality Monitoring in AgricultureThis presentation will focus on the importance of protecting water quality, the active role our ag partners play. Additionally, water quality monitoring technologies and methodologies including our use of not only industry tech, but also instruments developed by the Agricultural Water Quality Program at CSU. The importance of outreach and getting knowledge back into the hands of producers will be highlighted. ... E. Wardle |
12. Converting Between Mehlich-3P and Olsen-P Soil Tests: What Can Go Wrong?Varying methodologies for extracting plant-available phosphorus (P) have been proposed since the initiation of soil test development in the early 1900s. Two tests that were developed and are still used widely in both the United States and Europe are the Olsen and Mehlich-3 test. Olsen P is predominately used in high-pH soils and Mehlich-3 is more common in neutral to acidic soils due to the nature of the extracting solutions. Many Western US soils are high pH and, thus, have used Olsen ... C. Rogers, Z. Simpson, J. Mott, P. Kleinman |
13. Cool Season Mineralization of Recalcitrant Organic N in Undisturbed Cores of Manured SoilsThe objectives of this study were to (1) quantify cool season N mineralization from recalcitrant organic N in soils with a long history of manure application and (2) examine the relationship between cool season recalcitrant organic N mineralization and a fall mineralizable N index. “Cool season” was defined as October to February for fields with winter crops and October to May for fields with no winter crops. Two in situ trials were conducted with undisturbed so... D. Moberg, D. Sullivan, R. Johnson |
14. Cover Crops and Compost Amendments for Organic Grape ProductionIncreased costs of fertilizers that rely on petroleum products coupled with increased pest control and transportation costs has prompted more management practices that can make use of local waste products and utilize cover crops to reduce purchased inputs. A burgeoning wine industry could benefit from organic production techniques; however, their effects on vine growth and grape quality have not been explored in New Mexico. Alternative vineyard floor management systems were evaluated for orga... A. Ulery, R. Flynn, R. Walser, M. Weiss, S. Guldan |
15. Dairy Manure Applications to Potatoes: Soil Property, Plant Nutrient, and Tuber Quality ResponseDairy manure applications have become a common practice in Idaho potato production, however the impacts on soil and plant agronomic properties are not well understood. Our objectives were to determine (1) how repeated dairy manure applications impact soil properties and plant nutrient uptake, and (2) how these changes influence plant nutrient interactions, tuber yield, and quality. Stockpiled dairy manure was fall-applied over a 6-year period to two adjacent potato product... A. Moore, A.B. Leytem |
16. Determining Plant Available Nitrogen from Manure and Compost Topdressed on an Irrigated PastureComposting manure is a practice that is gaining acceptance as an environmentally sound manure management practice at large animal production operations. Composting produces a value-added product that enhances the fertility and physical properties of soil. During the composting process, nitrogen and phosphorus in the original feedstocks are converted through microbial activity into predominantly stable organic compounds, lessening the risk of loss of these nutrients into the environment. Compo... J. G. davis, T. Bauder, K. Corwin doesken, A. Elliott |
17. Developing Extension Guidance for Management Effects on Ammonia Loss: a Computer Simulation Modeling ApproachComputer simulation models provide insight into ammonia loss processes and the sensitivity of ammonia loss predictions to environmental and management variables. As an example of how a simple computer simulation model can inform the Extension guideline development process, the ALFAM (Ammonia Volatilization from Field-Applied Animal Slurry) model was used to estimate NH3 loss from surface- applied municipal biosolids: liquid (3% dry matter) and dewatered (22% dry matter). Model ... D. Sullivan |
18. Effect of 4R Nitrogen Management on Residual Soil Nitrate and Soil HealthNitrogen 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 ... K. Deep, M. Yost, J. Williams, B. Hopkins, G. Cardon, B. Black |
19. Effectiveness of Kitchen Compost in Germinating Tomato and LettuceFood waste in developed countries is a large input to landfills. Ideally, it is composted and added to soil on-site to reduce environmental impacts. A “kitchen composter” (ReencleTM) effectively decomposes waste within 24 hours (>90% reduction in mass), followed by formation of stable compost within a few weeks after curing outside the composter. Our preliminary research demonstrates that the compost has excellent nutrient composition. However, it was not adequately ... B. Hopkins, R. Kerr, S.V. Nelson |
20. Efficacy of FUSN as an N Source for Irrigated Vegetable CropsThe Department of Homeland Security Ammonium Nitrate Security Program regulates the distribution and sale of granular ammonium nitrate fertilizer (AN). Due to the bureaucracy of these regulations, the sale of dry AN has been discontinued in many areas. While liquid AN20 remains available, there is a preference for granular fertilizer for many agricultural applications. FUSN (20-0-0-14S) is a Honeywell and JR Simplot proprietary technology whereby ammonium nitrate is fused wi... C. Sanchez |
21. Evaluating Potential Impacts of Land-applied Food Processing By-products on Soil Quality and Plant NutrientsFood processing canneries, especially those using raw fruit, nut, and vegetable- base materials, generate various types of by-products or non-hazardous wastes. The constituents of these wastes are dependent on the source of raw material and the substances associated with the canning processes. The use of land-applied non-hazardous wastes as an agricultural soil amendment is projected to rise because of public concerns regarding environmental impact and economic restraints of their disposal to... S. Pasakdee, N. Dellavalle |
22. Evaluation of N Uptake Analysis As a Tool for Determing Potato N StatusPlant tissue testing has become the primary method for evaluating nitrogen availability for potatoes during the growing season. This study was conducted to determine if plant N uptake rates referenced to absorbed solar radiation could also be used as a tool to quantitatively assess plant N status of different potato varieties. Nitrogen fertilizer, as NH4NO3 (34-0-0), was applied to Russet Burbank, Gem Russet, Bannock Russet and Summit Russet at three rates (0, 100, or 300 kg N/ha) using ... J. Stark, S. Love, C. Mcintosh |
23. Evaluation of Soil Sulfur Tests for MontanaThere are no sulfur (S) fertilizer rate guidelines in Montana due to inconsistent yield responses, high S soil levels in many regions, a minimal number of S fertility trials in the state, and the lack of Montana and regional data that identify the best soil S tests to use. A study was initiated in 2023 to fill this research void. Three crops (spring canola, pea, and wheat) were grown at three sites, and fertilized with 0, 7.5, 15, and 30 lb S/ac using two S sources (potassium sulfate, gypsum)... C. Jones, P. Miller, P. Carr, S. Koeshall, S. Fordyce, J. Souza, J. Vetch |
24. Fava Bean Diversity and its Potential in the Western United StatesFava bean (Vicia faba), known for its biological nitrogen fixation, and grain and fresh pod production, is cultivated worldwide. In the western United States, fava bean, Bell bean, is mainly grown in cover crop mixtures to enhance soil nitrogen. While land size and lack of planting and harvesting equipment limit fava bean as grain crop, it is grown in small areas of western US for fresh pod as a vegetable crop. This presentation summarizes the findings of multi-year research on genetic divers... K. Brasier, H. Zakeri |
25. Grain Protein Content and Composition of Winter Wheat Cultivars Under Different Levels of N and Water StressThis study investigated the combined influences and interactions of N fertilization and moisture deficit during grain-fill on wheat grain protein content and grain protein composition of nine white winter wheat cultivars. Grain was obtained from seven HWW wheat cultivars and two soft white winter (SWW) wheat cultivars grown under line-source irrigation systems at two Oregon locations during two years. The low N level treatment consisted in a single fertilization of 150 lb N/a in Mar... A. Ross, C. Saint pierre, C. Peterson, J. Ohm, M. Verhoeven, M. Larson, B. Hoefer |
26. Greenhouse Lime and Gypsum Placement Strategies for Addressing Soil Acidity in No-tillDryland soft white winter wheat growers in the inner Pacific Northwest states including Washington, Oregon, and Idaho practice no-till to preserve the health and structure of their soil. Beginning in the 1960's, due to the usage and ammonium fertilizers and the nitrification of these fertilizers, the natively alkaline soils in this region have become increasingly acidic resulting is issues like low soil pH, mineral nutrient deficiencies, and aluminum toxicity. Gen... A. Moore, S. Ellickson |
27. Hydrothermal Carbonization of Dairy Manure for Phosphorus Recovery and Runoff Risk Mitigation: Effect of Temperature and CaO AdditionDairy manure contains a significant amount of phosphorus (P) and nitrogen (N), which are essential for soil fertility and crop productivity, but are currently underutilized due to ammonia emissions, P runoff and leaching, and manure N to P ratios do not match crop nutrient needs. Meanwhile, there is a growing concern about P depletion as a non-renewable resource. To address both the excessive use of synthetic P fertilizers and inefficiently direct use of dairy manure, a logical strategy is to... M. Islam, B. He, L. Chen |
28. Insights from Soil Health Assessments Across a Diverse Soils and Land Uses in the TropicsLand stewards can utilize soil health metrics to evaluate changes in their management practices. However, while indicators of soil health reflect specific ecosystem functions, the relationship of soil health measurements to anthropogenic disturbances, productivity, and other soil properties is poorly understood. The Hawaiʻi Soil Health database serves as a comprehensive collection of soil data from over 1,700 samples representing 11 of the 12 recognized soil orders across various land uses i... T. Maaz |
29. 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 |
30. Lime Incubation for Southern Idaho SoilsSoil acidity is a growing concern for agricultural productivity in Idaho, particularly in the eastern and northern regions where soils are trending acidic. Soil acidity below a pH 5.5 adversely affects the root development and nutrient uptake of crops like alfalfa, barley, and wheat. This study aims to determine the lime requirements for acidic soils in Idaho to optimize crop growth, specifically targeting pH levels of 5.5, 6.0, 6.5, and 7.0. Soil samples were collected from various grower fi... K. Young, J. Spackman, T. Jacobsen, J. Sagers, J. Hatch, R. Ritchie, J. Williams, K. Schroeder, A. Adjesiwor |
31. Liming for Improved Nutrient Utilization and Weed Management in WheatSoil acidification is an increasing concern for agricultural productivity in Eastern Idaho, where low soil pH threatens the yield and quality of key crops such as barley and spring wheat. Acidification occurs from the long-term application of ammonium-based fertilizers and other management practices, leading to aluminum toxicity and nutrient imbalances that inhibit root development and reduce yields. Farmers in the region are exploring strategies to address this challenge, including the use o... T. Jacobsen, J. Spackman, A. Adjesiwor, J. Sagers, K. Schroeder, J. Bevan, K. Mookodi, J. Gibbons |
32. Malt Barley Yield and Quality Response to Nitrogen and Sulfur FertilityNitrogen (N) and sulfur (S) and are critical nutrients for producing high-quality malt barley but can be difficult to manage in semi-arid production systems where rainfall and, periodically, irrigation is variable. High spring precipitation or excessive irrigation events can favor N and S leaching reducing yield and grain quality. However, N fertilizer additives such as urease inhibitors, nitrification inhibitors, and controlled-release products may improve N availability. Irrigated... J. Spackman, J. Spackman, J. Hatch, J. Bevan |
33. Management Techniques to Optimize Soil pH in Organic Highbush BlueberryA 3-year study was established in eastern Oregon, USA, in a new organic planting of ‘Duke’ northern highbush blueberry (NHB) to evaluate soil acidification methods. Six techniques of applying elemental sulfur (S) prills, with or without additional acidification of irrigation water were tested. Treatments consisted of: 1) a grower standard of soil incorporated S prills at 1700 kg·ha-1 applied 8 months pre-plant; 2) 8-weeks of fertigation totaling 150 kg&middo... S. Lukas, S. Singh |
34. Managing Potassium for Organic Crop ProductionAn adequate potassium (K) supply is essential for both organic and conventional crop production. Various organic certification agencies have different regulations governing allowable sources of K. The release of K from soil minerals is discussed along with the behavior of various allowed K sources for organic crop production. ... R. Mikkelsen |
35. Managing Soil AcidificationThe presentation will explore the relationship between nitrogen fertilizers, soil acidity, and nutrient stratification in agricultural systems. We will discuss how N fertilizers contribute to soil acidification over time. The role of soil pH in nutrient availability and plant health will be highlighted. The discussion will focus on alternatives to mitigate soil acidification, such as lime application, balanced fertilization, and improved management practices, ensuring long... J. Souza, C. Jones, P. Miller, M. Rakkar |
36. Manure Treatments Change Nitrogen Cycling in Soils Receiving Repeated Applications of Dairy-wastesOur objective was to assess effects of treated dairy-waste on soil N pools, nitrification, plant N availability, and yield in a silage cornfield treated with ammonium sulfate (AS), dairy-waste compost (DC) or liquid dairy-waste (LW) as N sources at two levels of application over 5 years. Increases in soil C and N, nitrate and available P and K were observed for the DC treated soils throughout the 5-year period. Soil organic C increases for the high-level DC treated soil doubled the C pool res... J. Norton, M. Habteselassie, J. Stark, B. Miller |
37. Micronutrient Management to Optimize Yellow, Brown and Oriental Mustard Production in Southern IdahoOilseed crops hold a significant position in global agriculture, serving as vital sources of essential oils and as raw materials for numerous industries. Among these, yellow, brown, and oriental mustard are prominent for their multifaceted uses, particularly in the culinary and industrial sectors. However, these mustard varieties face challenges in achieving their maximum yield potential, largely due to suboptimal nutrient management practices. Fertilizer programs, though essential for produc... H. Ali, J. Spackman, J. Pandey |
38. N Fertilizer, Does It Burn Up Organic Matter?Does synthetic N fertilizer deplete soil organic carbon, thereby exacerbating agricultural contributions to climate change? Or does synthetic N fertilizer instead increase soil organic carbon by boosting primary productivity and soil carbon inputs? The bulk of the evidence suggests that soil organic carbon increases with synthetic N fertilizer due to increased carbon inputs and decreased microbial mineralization of older soil organic carbon. ... G. Lahue |
39. New Tools in Soil and Manure Test Information Interpretation in UtahAn effort is underway to update the USU Analytical Laboratory’s (USUAL) procedures and data presentation/interpretation capabilities. Modern database management tools and analytical instruments have, in many cases, gone under-exploited in reducing sample turn-around time, in improving data dissemination and interpretation, and in providing research and extension personnel with access to comprehensive historical and current trend data on soil fertility, and manure and plant analysis.... G. Cardon, J. Kotuby-amacher |
40. Nitrogen and Phosphorus Fertigation on PearsAvoiding over-application of nitrogen (N) and phosphorus (P) fertilizers and increasing N and P use efficiency on pear orchards have significant benefits on pear productivity and the environment. Split fertigation of N and P fertilizers and banding application of N and P fertilizers may increase the use efficiency of applied N and P fertilizers compared with our current N and P management system -- single broadcasting application of dry N and P fertilizers to the soil surface. A field experim... F. Yin, C. Seavert, J. Bai |
41. Nitrogen Cycling and Partitioning Under Alternative Organic Orchard Floor Management StrategiesOrganic orchard systems are a significant and growing component of Washington State agriculture, yet sustainable methods of nitrogen (N) fertility and weed management remain a challenge. Nutrient supply is dependent on decomposition and mineralization of organic matter, yet intensive cultivation commonly used to control weeds can disrupt biological processes and cause loss of organic matter. To address the often-competing goals of organic fertility and weed control, a number of alternative or... L. Carpenter-boggs, D. Granatstein, J. Reganold, L. Hoagland, M. Mazzola, F. Peryea, J. Smith |
42. Nitrogen Removal Potential of Triticale in Cropping Systems Receiving Dairy Effluent ApplicationsField applications of lagoon effluent are common for dairy production systems in Northeastern Oregon. However, N in the effluent is susceptible to nitrate leaching losses which can cause water quality issues, especially from winter effluent applications when crop N uptake is slower. Triticale, which is derived from a cross between rye and wheat, is a common forage crop in this region that is well suited to take up excess nutrients like N. The objective of the project is to evaluate the in-sea... A. Jenkins |
43. No-till Grain Production in Wyoming: Status and PotentialIn dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, or continuously, without fallow, but water and nutrient needs are much more closely balanced wi... J. Norton |
44. Non-destructive Measurement of Perennial Crop N StatusLittle research has been conducted to evaluate the use on hand-held leaf meters as tools to assess plant N status in perennial crops. In this study, using replicated N rate plots in place for up to four years, we used two hand-held leaf meters (the Minolta SPAD meter and the Field Spec CM1000) to monitor tissue N status in apple and one meter (CM1000 only) in wine grape. In both crops, relationships were found between leaf meter readings and both fertilizer N rate as well as tissue N concentr... J. Davenport, R. Stevens, E. Perry |
45. Non-dormant Alfalfa and Small Grain Rotations- Tillage and Fertility EffectsTo study the use of non-dormant and high nitrogen fixing alfalfa cultivars as a possible source of nitrogen for spring and fall-seeded wheat and barley grown under tilled and no-tilled conditions. Hi-Nitro, a non-dormant, high-nitrogen fixing alfalfa variety, and RoundUp Ready Stratica, a traditional dormant alfalfa cultivars were clear seeded in Aberdeen in 2023 and 2024. Forage was harvested 4 times. Fall or spring tillage was done approximately 3-14 days before planting fall or s... R. Findlay, J. Spackman, J. Hatch, T. Jacobsen, J. Gibbons, J. Sagers, D. Callister |
46. Nutrient Cycling in Effluent-irrigated Soil (Mollisol) Planted to Tropical Grasses in a Tropical Island EnvironmentDairy producers accumulate large quantities of effluent in lagoons. Lagoons occasionally overflow causing the nutrients and other contaminants in effluent to pollute the land and water bodies. Alternative uses of effluent are, therefore, urgently needed for a sustainable and environment-friendly dairy production. This study determined the sustainable effluent application rate and assessed the effects of effluent irrigation on plant and soil (Cumulic Haplustoll) properties. Five tropical grass... R. Valencia-gica, R. Yost, G. Porter, R. Pattnaik |
47. On-Farm Variable-Rate Nitrogen Management in PotatoApplying variable nitrogen (N) has often improved yields, quality, and/or N use efficiency (NUE) of several crops. The objective of this study was to evaluate how pre-emergence variable rate N (VRN) zones vs. uniform N management impacts potato (Solanum tuberosum L.) yield, quality, and NUE. Low, average, and high N zones were created and evaluated for 10 site-years at fields near Grace, Idaho, USA over two years with rates based upon yield goals, soil, water, and previous crop ... E. Flint, M. Yost, B. Hopkins |
48. Optical Sensing for Nitrogen ManagementAlthough 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 |
49. Patterns and Implications of Increasing Sulfur Fertilizer Use at National-to-Global ScalesSulfur (S) is a key component of life and an element that has been dramatically changed by industrial activities, including mining and fossil fuel combustion. Today, as atmospheric S deposition declines in response to air quality regulation in the U.S. and Europe, there has been an increase in S fertilizer applications reported in many large, regional crop systems. In addition, intensification of agriculture has driven increased S inputs for other uses: as a pesticide, regulator of soil pH, a... E. Hinckley |
50. Phosphorus and Zinc Interactions in PotatoPotato production requires high soil phosphorus (P) application with potential negative environmental and nutrient uptake effects. Impacts of high available P on species in potato cropping rotations are not adequately understood, nor have the causes of reduced yield and quality from excess P been fully explored. Antagonistic interactions with cationic micronutrients such as zinc (Zn) are plausible explanations. Two hydroponic experiments were conducted with Burbank potato to elucidate P and Z... B. Webb, B. Hopkins, J. Ellsworth, S. Barben, B. Nichols, V. Jolley |
51. Phosphorus Dynamics and Wheat Response to Applied P in a Spatially Variable Environment1Considerable spatial and temporal variability exists in soil chemical and physical properties across farm landscapes in eastern Washington State. The purpose of this research is to investigate changes in P mineralogy across the Palouse landscape and ultimately to determine the influence of mineralogy on plant-available P and fertilizer P responses at different landscape positions. Soil samples were collected from landscape positions with varying soil pH and soil test P concentrations. Mineral... R. Koenig |
52. Plant Test Method Precision, Correlations, and Trends: SSSA-NAPT Historical DataThe Soil Science Society of America’s (SSSA) North American Proficiency Testing (NAPT) operates as a not-for-profit service laboratory resource since 1998 to assist/evaluate agricultural and environmental testing laboratories with quality assurance and quality control. Soil (n = 5 samples each quarter), plant (n = 3), and/or water (n = 3) samples collected nationwide are submitted quarterly to ~150 participating laboratories who choose which method(s) to use for which analytes they... S.V. Nelson, J. Lawley, T.J. Hopkins, G. Cardon, B. Hopkins |
53. Polymer Coated Urea in Potato ProductionNitrogen (N) is the most important mineral nutrient in potato (Solanum tuberosum) production. Studies show a steady, but not excessive, supply of N is important for maximum tuber yield, size, and solids, as well as minimal internal and external defects. Although more costly and labor intensive dry broadcast applications, growers typically apply the majority of N through the irrigation water in-season in order to maximize yield components. A controlled release N fertilizer, in the form of poly... B. Hopkins, T. Taysom, A. Shiffler, S. Stephens |
54. Polymer Coated Urea: Microplastics in Agricultural LandscapesPolymer Coated Urea (PCU) is effective in supplying nitrogen (N) to plants with reduced leaching, denitrification, and volatilization losses to the environment. However, microplastics pollution is a concern due to residual amounts in soil and possible transport to surface water. The purpose of this irrigated sweet corn (Zea mays convar.) field study at Provo, UT was to determine the potential for off-site transport of plastic coatings in agricultural landscapes. Treatments included a... C. Seely , J.J. Lemonte, B. Hopkins |
55. Precision Fertilizer Management Enabled by Printed Sensors for Direct Soil Nitrate MonitoringModern farming relies on intensive fertilizer applications to ensure the plant production. However, a key challenge in fertilizer management, particularly nitrogen, is achieving a balance between maximizing crop yields and pursuing environmental stewardship. Uniform fertilizer applications often result in inefficiencies. Some areas receive insufficient fertilizer, resulting in reduced crop yields and caused financial losses. In contrast, other areas receive excessive amounts, leading to surpl... K. Chen, J. Andrews |
56. Precision N Management: Field-scale Application of N Efficiency Indices in WheatPreliminary evaluation of precision agricultural technologies showed that on-combine grain yield and protein monitors show promise as useful tools to characterize site- specific variations in crop performance. Variable rate applicators were shown to be proficient at achieving targeted site-specific application goals. First year comparisons of uniform versus precision N management in hard red winter wheat showed that similar yield and protein goals were met with 20% less applied N in the field... D. Huggins |
57. Predicting Nitrogen Mineralization from Dairy Manure in Semiarid Cropping SystemsTools are needed to estimate N mineralization from application of dairy manures in semiarid irrigated soils. We found that N mineralization was affected by manure application rate, timing and broadleaft residue N. Average N mineralization was 27 and 18% of the N applied the 1st and 2nd year following application, respectively. The best predictors of N mineralization were soil organic matter, soil EC, manure N and broadleaf N residue. ... A.B. Leytem |
58. Predicting Phosphorus Runoff from Calcareous SoilsStudies have shown that as extractable soil P levels increase, runoff P levels also increase. This relationship has been found on many different soils, but tends to be unique for each soil series. Very little research exists evaluating this relationship in calcareous soils. The objectives of this study were to determine soil series specific relationships between soil test phosphorus (STP) and runoff P for three calcareous soils, to compare the use of different soil extractants for runoff P pr... J. G. davis, R. Schierer, J. Zumbrunnen |
59. Quality of Alfalfa Hay As Influenced by Phosphorus and Potassium FertilizationIn two field experiments, research was conducted to determine impacts of nutrient applications on alfalfa hay quality and nutrient value at Irrigated Research and Extension Center near Prosser, WA. The phosphorus (P) study P soil tests levels were 6.7 and 5.7 ppm at the beginning of 2019 and 2020, respectively (Olsen P test) in 2019 and 2020. The potassium (K) study was conducted on a soil test level of 85 and 78 ppm K in 2019 and 2020, respectively. Applying phosphorus increased protein, NDF... S. Norberg, D. Llewellyn, J.P. Driver, S. Fransen |
60. Quinoa Mineral Nutrient Deficiency Symptoms and ConcentrationsMajor crop nutrient symptoms are well documented. In contrast, there is often minimal or no similar information for minor crops, including quinoa (Chenopodium quinoa Willd.). This knowledge gap can be efficiently filled by using hydroponic systems. However, creating multiple nutrient deficiencies with plants in the same study is challenging because nutrients are often added as dual nutrient salts. For example, if potassium sulfate is the potassium (K) source, varying K concentra... B. Hopkins, G. Bell, S.V. Nelson, R.E. Sannar |
61. Recent Advances in P Fertilizer Technologies—polymer Coatings and Avail TechnologyPhosphorus fertilizers are an essential part of plant production and have been recognized as such for well over 100 years. Phosphorus utilization by crops is related to both soil availability as well as an individual plants metabolic process that allows P to be taken up by a plant as well as utilized for a wide variety of developmental processes. ... T. Tindall |
62. Recovered Carbon Black from Pyrolyzed Tires as a Zinc Fertilizer for Field Corn in Calcareous SoilsWaste 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 Z... R.E. Sannar, E. Bremer, K. Greer, B. Hopkins |
63. Reducing Dairy Effluent Phosphorus Content Through Struvite ProductionForced precipitation of struvite (magnesium ammonium phosphate hexahydrate, MgNH4PO46H2O) in wastewater treatment has recently received increased attention as a method of phosphorus (P) recycling. Dairy lagoon P concentrations can be lowered, and the recovered struvite has the potential to be marketed and used as a fertilizer. Struvite may even be useful in organic production on calcareous soils, where rock P (PR) is not an option. A new organic treatment method, based on an exis... J. G. davis, J. Ippolito, M. Massey, R. Sheffield |
64. Relationship Between Nitrogen Mineralization and Soil TextureSoil texture can affect soil temperature, soil moisture, the protection of organic material against microbial degradation, and other soil properties. All these factors potentially influence net nitrogen (N) mineralization. I will discuss results from a 10-week laboratory incubation of undisturbed soil cores from 47 sites in California, and a meta-regression analysis of 461 datasets from 20 studies. ... D. Geisseler |
65. Remote Sensing of Corn N Status with Active SensorsDetermining 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 |
66. Remote Sensing of Grape K Deficiency Symptoms Using Leaf Level Hyperspectral ReflectancePotassium (K) is an important nutrient for grape because it sustains charge neutrality during organic acid transport, is a major ion involved in osmoregulation and stomatal function and contributes to pH status in grapes and wines. We assessed the utility of a number of vegetation indexes for detection of K deficiency symptoms in a commercial vineyard of Vitis vinifera cv Pinot Noir. A hyperspectral field spectroradiometer for the 350-2500 nm spectral region was used to measure light reflecta... D. Smart, M. Whiting, C. Stockert |
67. Removing Nitrogen, Phosphate, and Fecal Coliform from Dairy Effluent Using Multi-soil-layer (Msl) SystemsDairy effluent disposal has long been a concern in Hawaii. Dairies often establish multiple lagoons to accumulate and store effluent. Occasionally, the lagoons overflow leading to the transfer of nutrients, such as nitrogen (N) and phosphorus (P), and other contaminants such as pathogenic bacteria to surface, subsurface, and coastal waters. The objective of this study was to quantify the effectiveness of MSL systems in removing inorganic nitrogen, phosphate, and fecal indicator organisms (Fec... R. Yost, R. Pattnaik, G. Porter |
68. Residual Phosphorus Effects on Alfalfa Seed Pollination and ProductionHigher available P that increases alfalfa biomass reportedly reduces alfalfa seed yield due to poorer pollinator visitation. Available P effects were evaluated in a three year (2004-06) study with in-row plant spacing (12”, 24”, 36” and 48”) at Parma, ID to investigate the mechanism for the yield decline. Plots differing in residual P from previously applied P were further enriched with 0, 25, 50, 75, or 100 lb P/A. Plots were split in the last year and a mix of foliar... B. Brown, J. Barbour |
69. Response of Desert Vegetable Crops to “40 Rock”- a P and Zn Fertilizer SourceCrops produced on calcareous soils in low desert region of the southwestern United States show a large response to P fertilizer. The most commonly used P source has been mono-ammonium phosphate (MAP or 11-52-0). These same soils are also reported to be marginal with respect to Zn availability but responses to Zn fertilization had been infrequent in the past. More recently, we have observed crop responses to Zn fertilization with increasing frequency and we have revised Zn fe... C. Sanchez |
70. Slow Release N for Irrigated Hard Red Spring Wheat Yield and ProteinProducing furrow irrigated hard red wheat with acceptable protein is challenging because of limited N management options for increasing protein. Slow release N has potential for improving N use efficiency in furrow irrigated hard wheat by avoiding the effects of excessive early season N yet providing later N for protein enhancement. A two year study (2005 and 2006) was conducted at Parma, ID to evaluate different N rates (120, 180 and 240 lb/A) of ESN and dry urea preplant N sources for furro... B. Brown, R. Gibson |
71. Soil Characteristics of New Mexico Vineyards: Management ImplicationsA growing viticulture industry in New Mexico has sparked a need to establish best management practices for the climate and soil conditions present across the state. A survey of soil and water characteristics in established New Mexico vineyards was performed so that appropriate management strategies could be developed and limitations could be identified. Soil nitrogen levels varied from low to high indicating potential problems. Plant tissue testing needs to be included in a phosphorus nutriti... R. Flynn |
72. Soil Property Effect on Nitrogen Mineralization of Dairy Manure in the Pacific NorthwestGrowers often use total nitrogen (N) concentration of dairy to manure to estimate plant available N for crop production. This estimate, however, ignores the role that soil properties may have on N mineralization (Nmin) rates. This study aims to determine how soil physiochemical properties impact Nmin rates of dairy manure and composted dairy manure by aerobic incubation. Sixteen soils, sampled from 0-12 inch depths (0-30.5 cm) were collected from dairy production regions in Oregon, Washington... R. Auld, A. Moore, J. Moore, Y. Zhang, C. Rogers |
73. Soil Sulfur Forms, Cycling, Management in Prairie SoilsSulfur exists in surface soils of the prairies mainly in the organic form, while subsoils may contain appreciable quantities of sulfate salts. Mineralization is a major input to the the plant available sulfate pool, with about 1 to 3% of organic sulfur mineralized over a growing season. About one half of the sulfur taken up by annual crops is present and removed in the seed. Declining inputs of S from the atmosphere and greater crop removal have increased the incidence ... J. Schoenau |
74. Soil Test Method Precision, Correlations, and Trends: SSSA-NAPT Historical DataThe Soil Science Society of America’s (SSSA) North American Proficiency Testing (NAPT) operates as a not-for-profit service laboratory resource since 1998 to assist/evaluate agricultural and environmental testing laboratories with quality assurance and quality control. Soil (n5 samples each quarter), plant (n3), and/or water (n3) samples collected nationwide are submitted quarterly to ~150 participating laboratories who choose which method(s) to use for which analytes they are inte... B. Hopkins, S.V. Nelson, G. Cardon, J. Lawley, T.J. Hopkins |
75. Soil Testing to Improve Phosphorus Management on Intensive Vegetable Farms in HawaiiAccording to a recent survey of soil samples sent to the Agricultural Diagnostic Service Center (ADSC) at the University of Hawaii between October 2002 and September 2003, a majority of the samples showed soil test P (STP) levels in the high or excessive categories. Despite high soil test P, many farmers in Hawaii continue to apply P fertilizers. We began a project to evaluate soil P status on a range of vegetable farms throughout the state, to determine crop response to P fertilizers on soil... J. Deenik, S. Fukuda, R. Hamasaki, R. Shimabuku, R. Uchida |
76. Soil Zinc Application for Southwestern PecanPecan trees grown in the alkaline soils of the southwestern United States are prone to zinc deficiency unless supplemental zinc is regularly applied. Standard treatment involves multiple foliar zinc applications. Soil zinc application would provide several advantages. A field study was initiated in 2005 with three soil zinc treatments: no zinc (control), ZnSO4 (74 kg.ha-1 Zn), or ZnEDTA (19 kg.ha-1 Zn) were applied one time in March, 2005 in bands 18 cm deep and 1.2 m on both s... J. Walworth, A. Pond, H. Nunez, B. Wood, M. Kilby |
77. Spatial and Temporal Variability in Wine Grape NutrientsLittle work has been done to address the extent of spatial and temporal variability in nutrients in wine grape vineyards. In this study, we assessed soil and plant nutrient distribution on a per vine basis, both spatially and temporally across two vineyards, a Ruby Cabernet vineyard in Sunraysia and a Cabernet Sauvignon vineyard in Coonawarra. Petiole tissue was collected at two growth stages: flowering and veraison. Berry tissue was collected at harvest. All samples were analyzed for the pla... J. Davenport, R. Bramley |
78. Spectral Response of Pulse Crops to Soil Acidity for Soil pH MappingIn this work, we explore the observable differences in the spectral reflectance of pulse crops in acidified and non-acidified soil regions of multiple Montana fields. Satellite observations are collected throughout the growing season using Landsat 8 & 9 and Sentinel 2 A & B. The variations of crop reflectance in acidified (pH < 5) and non-acidified (pH 6.0 to 7.0) are analyzed and used to support why both multi-temporal regression and machine learning models are... P. Nugent, S. Feleghari |
79. Speculation on an Equation for Stratification: How Reliably Can We Estimate Soil Test Values at Different Depths?The depth to which soil is sampled in a field impacts measured soil test values. However, across the West, depth of soil sampling can vary by state, region and cropping system. What if we're interested in comparing crop responses to fertilizer application across a large scale? How do we reconcile trials that are sampled at different soil depths? This study was part of the Fertilizer Recommendation Support Tool (FRST) project, with the goal to develop equations that allowed comparison... S. Culman |
80. Sugar Beet Lime Characteristics and Effects on High pH Soils and Crops in the Western U.S.Each year in Idaho and Oregon, 351,000 Mg of precipitated calcium carbonate (PCC) (a byproduct of sucrose extraction from sugarbeet) is produced and stockpiled at sugarbeet processing factories. Currently there are limited disposal strategies for the PCC and these stockpiles continue to grow over time. The simplest solution would be to apply the PCC directly to agricultural fields each year, however the effects of PCC on high pH soils and crop rotations in the growing area are not well unders... D. Olsen, D. Bjorneberg, D. Tarkalson |
81. Tillage Effects on Phosphorus AvailabilityVertical stratification of phosphorus (P) has been documented in both no-till and reduced tillage systems, yet very few studies have determined if this stratification has affected P uptake, and none of these studies have been conducted in Montana. Stratification of P was compared in 1.2 in layers in a small plot study composed of four tillage systems: long-term conventional (sweep) till (CT), 10-yr no-till (NT), 1-yr NT and 1-yr CT. Olsen P was measured in the upper 12 in., and a sequential e... C. Jones, K. Neill, C. Chen, E. Allison |
82. Updated Fertilizer Guidelines for Vegetable Crops in ArizonaThe vegetable production industry in the lower Colorado River region of Arizona is valued at over 19 billion dollars. Comprehensive fertilizer guidelines for vegetable crops historically produced in Arizona had not been updated in decades. Furthermore, we had no data to support guidelines for newer vegetable crops introduced into the region during the past two decades. The updated guidelines consolidate decades of research, incorporating historical databases, augmented with releva... C. Sanchez |
83. Urea and Ammonia Volatilization in Dryland Grass Seed Systems1The purpose of this study was to evaluate the influence of grass seed production conditions and management practices on NH3 volatilization, Kentucky bluegrass seed yields and N recovery from urea. Laboratory incubations suggest the potential for NH3 volatilization is greater from stands in which post-harvest residue is baled and removed than from stands in which residue is burned. Both burned and unburned stands have a surface pH > 7.9, although pH declined with time in the burne... R. Koenig, C. Proctor, W. Johnston, C. Golob |
84. Variability of Manure Nutrient Content and Implications for Manure Sampling ProtocolThe variability of manure nutrient levels within and across farms makes manure sampling and development of reliable tabular values challenging. The chemical characteristics of beef, dairy, horse, sheep, and chicken solid manures in Colorado were evaluated by sampling six to ten different livestock operations for each manure type and comparing the results to values found in the literature. Due to the semi-arid climate of Colorado, manure tends to be drier and have lower ammonium (NH4-N) levels... J. G. davis, K. Iversen, M. Vigil |
85. What is a Plant Nutrient? Changing Definitions to Advance Science and Innovation in Plant NutritionWe propose a new, more comprehensive definition of mineral plant nutrients that extends beyond the current narrow criteria. This expanded definition encompasses not only essential elements but also those that are beneficial for plant growth, development, or quality attributes across various species and environments. The proposed definition recognizes elements with clear metabolic functions and those that enhance plant productivity, crop quality, resource use efficiency, stress tolerance, or p... P.H. Brown |
86. What You Need to Know About the National Fertilizer Recommendation Team Called FRSTThe Fertilizer Recommendation Support Tool (FRST) team is a national effort to improve coordination of soil test recommendations in the United States. There are over 125 partners involved in FRST with representation of all four regional soil testing committees including WERA-103. The team has developed a national tool for P and K soil test calibrations (identifying critical soil test values for response to fertilizer), and are working on developing P and K calibration, tools for S calibration... M. Yost, N. Slaton, J. Spargo, D. Kaiser, G. Buol, L. Gatiboni |