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1. Is Cover Crop Species Mixture and Diversity More Important at Building Soil Health than Shoot Biomass in a Semi-arid Region?Cover crop mixtures (CCMs) as partial fallow replacements have the potential to increase soil health, yet long-term studies on CCMs, especially in semi-arid environments are relatively rare. An eight-year study at two locations in semi-arid Montana sought to evaluate the effect of functional group (N fixer, tap roots, fibrous roots, brassicacae) and species richness (2, 6, and 8 species in a mix) on a range of biological, physical and chemical soil parameters. Although several soil health... P. Miller, C. Jones, C. Zabinski, K. D'agati, M. Housman, S. Tallman |
2. Repurposing Zinc from Mining Tire Waste to a Fertilizer ResourceZinc (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 |
3. 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 |
4. Evaluating Nutrient Uptake and Partitioning for Hybrid Carrot Seed Production in Central OregonHybrid 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 |
5. 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 |
6. Residue Decomposition of Surface and Incorporated Barley, Corn, and Wheat at Varying Fertilizer-N RatesCereal crops are commonly grown in southern Idaho and most parts of the western United States. These cereal crops are routinely harvested for their grain with the remaining plant material (chaff, stems, leaves, etc.) left in the field to decompose prior to planting of following spring crops. Understanding the effects of post-harvest residue management on barley (Hordeum vulgare L.), corn (Zea mays L.), and wheat (Tritcum aestivum L.) residue is important for optimizing... C. Rogers, G. Thurgood, B. Dari, J. Marshall, O.S. Walsh, K. Schroeder, G. Loomis |
7. Evaluation of Nitrogen Fertilization and Drip Irrigation Levels on Yields of San Joaquin Valley, California, Forage Corn and Sorghum CultivarsIn California (CA), approximately 500,000 acres of corn are grown annually, with most grown for dairy forage. Under reduced irrigation water (IW) supply conditions, forage sorghum acreage can increase to 90,000 acres annually. Corn nitrogen (N) demand is well documented in studies conducted outside of CA, but little research on forage corn and sorghum N use efficiency (NUE) under varying levels of IW has been conducted. With such a large statewide acreage, it is important to improve... R. Hutmacher, N. Clark, J. Dahlberg, J. Angeles |
8. Developing Practical Phosphorus and Potassium Tissue Test Recommendations and Utilizing Struvite in Modern Alfalfa SystemsTissue testing whole alfalfa plants at harvest provides opportunities to direct nutrient decision making more accurately. Critical levels developed allow in- season recommendations and applications and would save producers time and effort since growers are already taking samples for hay quality. Three experiments were designed including: P Study with differing rates of P2O5 using monoammonium phosphate (MAP); including: 0, 30, 60, 120, 240 lbs./acre on an 8.1 ppm P soil (Olson P method);... S. Norberg, E. Mackey, S. Fransen, J. Harrison, D. Llewellyn, L. Whitefield |
9. Application of Ion Exchange Resin Membranes to Nitrate Testing in the WestResin membranes have been used since the 1960s to measure P supply from the soil. In the 1990’s the Plant Root Simulator (PRS®) probe was invented to further refine a method to measure N mineralization from soil organic matter. The functional measurement of soil N supply during incubation has been applied to both in situ measures and in lab research studies. Extending the PRS® measurements of N ‘intensity’ or flux to a meaningful number that a plant can utilize was accomplished... K. Greer, E. Bremer, T. Sievers |
10. Soil Management Assessment Framework Use for Identifying Soil Quality Changes in Irrigated AgricultureThe 820 km2 Twin Falls (Idaho) irrigation tract is part of the Natural Resources Conservation Service (NRCS) - Conservation Effects Assessment Project (CEAP). Furrow irrigation was initiated in the early 1900s but, since the 1990s, the NRCS Environmental Quality Incentives Program (EQIP) and other specialty projects have resulted in conversion of approximately 40% of the irrigation tract area to sprinkler irrigation. Most past CEAP research has focused on water quantity and quality, effects... J. Ippolito, D. Bjorneberg, D. Stott, D. Karlen |
11. Improving Nitrogen Use Efficiency of Cool Season Vegetable Production Systems with Broccoli RotationsNitrate leaching in leafy vegetable production in the Salinas Valley, CA is a continuing problem. Increased levels of nitrate in groundwater resources affects the ability of municipalities to access drinking water that meet federal water quality standards. Regulations by the Central Coast Regional Water Quality Control Board are now requiring growers to improve nitrogen use efficiency (NUE) in production fields. In prior studies we found that above ground biomass nitrogen (N) at crop maturity... R. Smith, M. Cahn, T. Hartz |
12. Nitrogen Availability and Use Efficiency in Corn Treated with Contrasting Nitrogen SourcesNitrogen (N) is required in relatively large quantities for corn production and is often the limiting nutrient for growth and high yield. Improved understanding of N cycling in agroecosystems is essential for increasing N use efficiency (NUE) and sustainable food production. The transformations between organic N and inorganic N form a central part of the internal soil N cycle. Utah farmers grow approximately 990,000 tons of silage corn annually, which provides important forage in livestock and... A. Kakkar, J. Norton, Y. Ouyang |
13. Polymer Coated Urea: Meeting Plant Needs While Mitigating Environmental Impacts — Research SummaryFertile soil is the foundation of food production and is maintained by replacing nutrients lost in harvest or to the atmosphere and hydrosphere. Nitrogen (N) accounts for approximately half of global fertilizer inputs. However, N recovery by plants is inherently inefficient due to “leaks” in the system, causing air and water pollution. Additionally, poor fertilizer efficiency is a waste of natural resources and potentially reduces yields, crop quality, and grower profits. Nitrogen-use... S. Bartholomew, T. Hopkins, B. Hopkins |
14. Drought and Nitrogen Stress Effects on Maize Canopy TemperatureWater 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 |
15. Nitrogen Management and Budgets for Irrigated Cotton in the Western USAWe present research on new and improved and updated N fertilizer management recommendations for 4-bale/acre cotton based on a 36-inch NO3-N soil test for irrigated cotton from a 2-year study on surface/furrow irrigation study and a 1-year study under sprinkler irrigation. We also compared UAN with UAN plus the N loss inhibitor Agrotain Plus. Additionally, we compared reflectance- based N fertilizer management with soil test-based management. Nitrogen balances indicated that residual soil NO3 was... K. Bronson, J. Mon, E. Bautista, D. Hunsaker |
16. Cropmanage: an Online Decision Support Tool for Irrigation and Nutrient ManagementVegetable and berry growers on the central coast of California are under growing regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of these crops are the soil nitrate quick test (SNQT) for monitoring soil residual N concentrations and evapotranspiration (ET)-based irrigation scheduling for estimating crop water requirements. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage),... M. Cahn, T. Hartz, R. Smith, B. Noel, L. Johnson, F. Melton |
17. Siderophores to Increase Iron AvailabilitySiderophores are biologically produced low molecular weight amino acids that act to chelate metals. These can be generated by soil microorganisms and some plants, most notably grasses, also produce siderophores. These compounds are associated with improved availability of iron in the soil. This manuscript presents a survey of microbial siderophores present in soils under chlorotic and non- chlorotic ‘Concord’ grapevines. ... J. Davenport, A. Pollard, T. Sullivan |
18. Response of Mesa Russet Potato to Potassium Fertilizer Source and Time of ApplicationResearch studies have shown that the source of potassium (K) fertilizer can influence potato tuber yield and quality. Most of the K fertilizer studies conducted have focused on muriate of potash (MOP) and sulfate of potash (SOP). Potassium Acetate (Bio-K) has been introduced as a new source of K fertilizer. Field studies were conducted at the San Luis Valley Research Center, Colorado State University, to evaluate the yield and quality response of potato cultivar Mesa Russet to source and time... S.Y. Essah |
19. Cover Cropping in the Semi-arid West: Effects of Termination Timing, Species, and Mixtures on Nitrogen Uptake, Yield, Soil Quality, and Economic ReturnSummer fallow still dominates some areas of the northern Great Plains (NGP), providing an opportunity to grow a partial season cover crop for increased soil health or nutrient availability. Over 12 years of research on single species cover crops in semi-arid Montana have revealed the benefits of early termination and multiple cover crop cycles on N availability, subsequent crop yield, soil health, and economic return. Due to high N fixation, pea cover crops have fairly consistently increased subsequent... C. Jones, P. Miller, S. Tallman, M. Housman, C. Zabinski, M. Burgess, J. O'dea, A. Bekkerman |
20. Alfalfa Contributes More Nitrogen to Following Crop Than Previously ThoughtAlfalfa in high-yielding environments fixes significant amounts of atmospheric N2, a portion of which benefits succeeding non-legume crops and reduces fertilizer N requirement by an amount sometimes called the “legume N credit”. Field research-based estimates of the legume N credit in California and other irrigated, semi-arid or arid environments are sparse in the literature. We conducted replicated plot experiments at three field station sites in California using wheat as an indicator... S. Pettygrove, E. Lin, D. Putnam, M. Lundy, S. Orloff, S. Wright |
21. Effects of Post-fire Soil Hydrophobicity on Inorganic Soil Nitrogen and Sulfur CyclingFire 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 |
22. The Effect of Cyanobacteria Biofertilizer on Western Colorado Organic Peach Quality and Yield CharacteristicsNitrogen (N) is the nutrient needed by crops in the highest amounts and the production of synthetic N fertilizers contributes the highest proportion of carbon dioxide to the atmosphere, when compared to other sectors of agriculture. Cyanobacteria are naturally occurring in most ecosystems and fix nitrogen gas from the atmosphere into forms which are useable by plants. Cyanobacteria was applied along with irrigation water to organically farmed peach trees (Prunus persica cv. Suncrest) as a... D. Sterle, G. Litus, F. Stonaker, S. Ela, J. Davis |
23. Effects of Commercial Organic and Cyanobacterial Fertilizers on Instantaneous Water Use Efficiency in Drip Irrigated Organic Sweet CornWater and fertilizers are applied to maintain crop growth, yield, and quality. Nitrogen (N) fertilizer plays a crucial role in crop growth and yield development of sweet corn (Zea mays). Organic growers often use commercial organic animal- based fertilizers which vary in nutrient composition, forms of available N (NH4+- N and NO3--N), and have high transportation costs. Alternatively, cyanobacteria can be grown on-site as a source of N. Cyanobacteria haves unique dual properties because they... J. G. davis, A. Sukor, C. Ramsey |
24. Effects of Enhanced Mixing and Minimal Co2 Supplementation on Biomass and Nitrogen Concentration in a Nitrogen-fixing Anabaena Sp. Cyanobacteria Biofertilizer Production CultureNitrogen-fixing cyanobacteria are attractive as a nitrogen fertilizer because they are ubiquitous in nature and have minimal nutrient requirements. Our lab is scaling up production of a local strain of the nitrogen-fixing cyanobacterium Anabaena sp. in on-farm open raceways to determine its exonomic ppotential as a nitrogen fertilizer for horticultural crops. Our goal is to increase productivity in an organically certifiable growth medium above the current two week batch production levels... J. G. davis, J. Wenz, H. Storteboom |
25. Effect of Liquid Organic Fertilizers and Seaweed Extract on Daucus Carota Var. Sativus Growth CharacteristicsCommon N fertilizers used in organic production are often energy intensive to produce and expensive to transport. Cyanobacteria fertilizer produced on-farm could decrease impacts on the environment as well as production costs for organic farmers. In addition, cyanobacteria fertilizer could perform similarly to products marketed to increase production via plant growth hormones such as seaweed extract. The effects of common organic fertilizers as well as organic liquid cyanobacteria fertilizer on... J. G. davis, A. Wickham |
26. Development of Leaf Sampling and Interpretation Methods for Almond and Development of a Nutrient Budget Approach to Fertilizer Management in AlmondA five year research project on the use of N in orchards crops has been conducted to 1) to develop early season sampling protocols, and 2) to determine the response of Almond to various rates and sources of nitrogen (N) and potassium (K) fertilizers, 3) to develop nutrient demand curves and 4) to conduct a long term assessment of nutrient use efficiency with the goal of improving fertilizer management. Leaf and nut samples were taken at 5 stages of development throughout five seasons to determine... P.H. Brown, S. Saa, S. Muhammad, B. Sanden |
27. Nitrogen Management in BlueberriesThree field trials were conducted in Corvallis, OR from 2006 to 2011 to evaluate nitrogen (N) fertilizer practices for establishment of highbush blueberry (Vaccinium corymbosum L.). In the first trial, planted in April 2006, we compared the effects of N fertigation (injection of fertilizer through a drip system) to conventional granular fertilizer application in ‘Bluecrop’ blueberry and found that fertigation produced more growth and less salt injury in young plants than granular... D. Bryla, O. Vargas |
28. Irrigation and Nitrogen Management Web-based Software for Lettuce ProductionLettuce growers on the central coast of California are under increased regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of lettuce are the quick nitrate soil test (QNST) for monitoring soil mineral nitrogen levels and weather-based irrigation scheduling for estimating water needs of the crop. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage), to facilitate... M. Cahn, R. Smith, T. Hartz, B. Noel |
29. Exploring Controlled Release Nitrogen Fertilizers for Vegetable and Melon Crop Production in California and ArizonaVarious forms of polymer coated urea (PCU) were examined as sources of controlled release nitrogen for production of cauliflower, watermelon, carrot, and spinach in Arizona or California. Studies were designed to demonstrate the effectiveness of PCU for supplying 100 percent of the fertilizer nitrogen needed for an entire growing season in a single pre-plant application. In each study, two or more N rates were tested. PCU having an appropriate release time for a given set of growing conditions... R. Smith, A. Blaylock, E. Ellison, C. Sanchez |
30. Efficient N Fertility and Irrigation Management in Vegetable and Berry ProductionNitrogen (N) fertility and irrigation management for vegetable and berry production has historically been done on an ‘agronomic’ basis, with the sole focus on producing the optimal crop. For these crops N fertilizer and water costs are a small portion of overall production costs, and an even smaller portion of crop value; consequently, these inputs have not been scrutinized as closely as they have been for lower value crops. However, throughout the West concern over environmental water... T. Hartz, R. Smith, M. Cahn |
31. Effect of Nitrogen Rate and Cropping System on Soil Nutrient Levels in a Long-term StudyDiversified continuous cropping systems in semi-arid regions of the northern Great Plains may enhance sustainability. A study initiated in 2000 in southwest Montana was designed to evaluate crop productivity and economic returns for no- till and organic rotations that included small grains, pulses, and oilseeds. Our specific objective presented here was to compare soil nutrient differences from 2004 to 2012, to learn if economically superior rotations were building or depleting soil nutrients.... C. Jones, P. Miller, T. Rick, A. Mccauley |
32. Forecasting Crop Nutrition Needs Using the Plant Root Simulator (PRStm) TechnologyConventional soil testing is based on the premise that a chemical extraction will reflect the soil nutrient supply to plants. The shortfalls of this approach have been evidenced by the numerous studies conducted over the past 50 years aimed at improving soil test methods. Radiotracer studies in the 1960’s where pivotal in shifting thinking away from nutrient concentration and toward mechanisms of nutrient supply. Barber (1995) first coined the term soil nutrient bioavailability to... K. Greer |
33. Measured and Predicted Temporal Changes in Soil Nitrate-n Levels from Late Summer to Early Spring in MontanaMost soil sampling is conducted from August to November in Montana because of better soil sampling conditions and because it provides more time for growers to make fertilizer decisions prior to application. Fertilizer guidelines in Montana are based on spring nitrate-N levels in the upper 2 ft because they are more indicative of growing season available N than fall nitrate-N levels. It is not known how much nitrate-N levels change between late summer and spring, nor is it known what factors affect... C. Jones, A. Lenssen, C. Chen, K. Mcvay, B. Stougaard, M. Westcott, J. Eckhoff, J. Weeding, M. Greenwood |
34. Delivery of Soil Science to Farmers Using Advanced Simulation Tools: a 10 Year Case StudyTechnologies 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 |
35. 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 |
36. Phosphorus Dynamics in Organic Matter-amended SoilsGenerally, phosphorus (P) is considered immobile in calcareous soils. Yet, numerous studies have found that the addition of organic wastes (e.g. manures) can enhance P mobility in these soils. We believe that the soluble organic matter present in these wastes increases P solubility by inhibiting the sorption of inorganic P on soil colloidal surfaces and subsequently preventing the formation of insoluble calcium phosphates. This results in increased P bioavailability. Likewise, tests used to assess... P. Grossl, R. Koenig, C. Jones, S. Trolove |
37. Economic Model to Determine Optimum Nitrogen Rates for Small GrainsNitrogen (N) fertilizer is generally the highest input cost for Montana grain growers; therefore, it has become imperative that a tool be developed to assist crop advisers and farmers in determining economically optimum N rates (EONR). Data from all available MSU-conducted N fertility trials were gathered for spring wheat, winter wheat, and barley. Only the data sets for dryland fields following fallow were deemed large enough to have confidence in any resulting models, and all other data were... C. Jones, D. Griffith, G. Jackson |
38. Comparing Nutrient Availability in Low Fertility Soils Using Ion Exchange Resin Capsules and Plant Bioavailability Under Greenhouse ConditionsCommonly 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 |
39. 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 |
40. 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 soils... J. Deenik, S. Fukuda, R. Hamasaki, R. Shimabuku, R. Uchida |
41. 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. Compost... J. G. davis, T. Bauder, K. Corwin doesken, A. Elliott |
42. 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 thorough... J. G. davis, A. Elliott, N. Marcillac, J. Pritchett, C. Stewart, A. Mink |
43. 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 extraction... C. Jones, K. Neill, C. Chen, E. Allison |
44. 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 existing... J. G. davis, J. Ippolito, M. Massey, R. Sheffield |
45. 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 prediction... J. G. davis, R. Schierer, J. Zumbrunnen |
46. Economics of Alfalfa Fertilization Under Inflated Hay and Fertilizer PricesKnowing 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 |
47. Determining Lime Requirements for Idaho SoilsFor the past 25 years, northern Idaho soils have significantly shown a decline in soil pH, from pH 6.0 to around a pH of 5.6. Southern Idaho soils are mostly neutral to alkaline, with a pH of around 7.0 to 8.5, however, most agricultural soils pH is declining to pH < 4.5. Soil acidification is becoming a rising issue in soil sustainability, in which approximately 30% of the world surface is covered by acidic soils. Low soil solution pH can be induced by continued irrigation that increases... K.L. Mookodi, J. Spackman, J. Sagers, K. Schroeder |
48. Development of a Constrained Resource Model to Support Intercropping DecisionsCrop 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 |
49. Improved Small Grain Nitrogen Use Efficiency with California Site-specific Decision SupportSmall grains are grown throughout the state of California (CA) on approximately 500,000 acres annually. They are generally fall-sown and grown during the winter months when most precipitation occurs. Because precipitation and irrigation patterns vary across CA and there is a strong interaction between total water and plant available nitrogen (N), determining fertilizer N application recommendations is particularly challenging in this cropping system. With recent fertilizer price volatility,... N. Clark, M. Lundy, T. Nelsen, M. Leinfelder-miles, S. Light, G. Galdi, T. Getts, K. Mathesius |
50. Spoon-fed Nitrogen and Phosphorus Management for Subsurface Drip Irrigated Cotton (Gossypium hirsutum)Subsurface drip irrigation (SDI) is becoming a popular option for maximizing the water use efficiency of cotton (Gossypium hirsutum), especially in semi-arid environments of the Midsouth and Western United States. Applying fertilizers through SDI provides an opportunity to prescriptively apply nutrients at peak nutrient demand which could minimize loss and increase uptake, but the application timing is poorly understood. The objective of this study was to develop nitrogen (N) and... J.A. Burke, K.L. Lewis |
51. Stacking 4R Nutrient Management: PotatoThe 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 |
52. Optimizing Nitrogen Fertilizer Rates for Annual Cereal Forage ProductionNitrogen fertilizer provides one of the greatest returns on investment but also one of the highest operating expenses for annual cereal forage production. It is important to know the total nitrogen required by a crop to optimize yield and quality and to minimize nitrogen losses to the environment. It is also possible that annual cereal forage species and cultivars will have varying responses to nitrogen availability. The objective of this study was to determine the optimal nitrogen fertilizer... J. Spackman, R. Findlay, J. Sagers, J. Pandey |
53. Nitrogen Management to Increase Cotton Production in Conservation Cropping SystemsThe 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 |
54. Response of Soil N Cycling, Nitrifying Organisms, and Winter Wheat Yield and Quality to Nitrification Inhibitors in High Rainfall Zones of Northern IdahoLeaching of fertilizer nitrogen contributes to environmental pollution and is an economic loss for agricultural producers. Leaching of inorganic nitrogen fertilizers is intensified when applied to areas of high rainfall zones in excess of crop requirements. Reduction of this nitrogen loss may be achieved through the application of nitrification inhibitors at the time of planting to prevent the transformation of ammonia to more leachable nitrate by nitrifying organisms. Much research on nitrification... S. Philpott, H. Tao, K. Schroeder |
55. Floral Hemp Responses to Nitrogen Fertilization in the High DesertThe performance of floral hemp under N fertilization is influenced by environmental conditions, management and cultivar selection. This field study evaluated the effect of no supplemental N and N fertilization at 90 kg ha-1 on three hemp cultivars (Berry Blossom, Red Bordeaux, and Tahoe Cinco) in Northern Nevada. Nitrogen increased plant height, canopy cover, stem diameter and shoot biomass, but other physiological parameters were dependent on cultivar. We evaluated the use... F. Barrios masias, M. Farnisa, J. Solomon, G. Miller |
56. Effects of Long-term Biosolids Applications in Two Dryland Agroecosystems on Physical, Biological, and Chemical Soil Health PropertiesBiosolids can be important sources of organic matter to semi-arid dryland grain systems and have the potential to mitigate some of the soil health challenges specific to these areas while providing an alternative to synthetic fertilizers. Biosolids are an important avenue for beneficially reusing and redistributing nutrients from high population urban areas to more rural agricultural areas. We explored how long-term (20+ year) applications of biosolids at two field sites affected physical, biological... M. Desjardins, A. Bary, J. Ippolito, S. Cappellazzi, D. Liptzin, D. Griffin-lahue |
57. CropManage Decision Support Tool for Improving Irrigation and Nutrient Efficiency of Cool Season Vegetables in California: a Decade of Field Demonstrations and OutreachVegetable growers on the central coast of California are under regulatory pressure to reduce nitrate loading to ground and surface water supplies. California is also implementing the Sustainable Groundwater Management Act (SGMA) which may limit agricultural pumping in regions such as the central coast where the aquifer has been over-extracted for irrigation of crops. Growers could potentially use less N fertilizer, address water quality concerns, and conserve water by improving water... M. Cahn, R. Smith, L. Johnson, F. Melton |
58. 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 |
59. 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 fields... K. Young, J. Spackman, T. Jacobsen, J. Sagers, J. Hatch, R. Ritchie, J. Williams, K. Schroeder, A. Adjesiwor |
60. 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, NDFD... S. Norberg, D. Llewellyn, J.P. Driver, S. Fransen |
61. 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 productivity,... H. Ali, J. Spackman, J. Pandey |
62. 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 of... T. Jacobsen, J. Spackman, A. Adjesiwor, J. Sagers, K. Schroeder, J. Bevan, K. Mookodi, J. Gibbons |