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1. 15Nitrogen Uptake and Use Efficiency in Corn in Response to Fertilizer Rate and TimingUrea 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 |
2. New Hydroponic System for Testing Mineral Nutrient Deficiencies: QuinoaCorrelating 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 |
3. 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 |
4. Denitrifying Woodchip Bioreactor Performance in the Pacific NorthwestRunoff 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 |
5. Enhanced Efficiency Nitrogen Fertilizer: Coated UreaNitrogen 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 |
6. 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 |
7. Assessing Nutrient Uptake and Accumulation in Oregon Hop ProductionCommercial hop production practices and cultivars have changed in the past 25 years and there is a need for updated nutrient management information under cotemporary practices. Current nutrient accumulation curves are only available for nitrogen (N). Current regional nutrient management guides from Oregon State University and Washington State University date back to the 1990’s or earlier. In the meantime, market forces and breeding efforts have led to a proliferation of new varieties, many... A. Moore, D. Gent, B. Verhoeven |
8. Impact of Soil Health Practices in an Irrigated AgroecosystemRegional farming practices in cold semiarid irrigated agroecosystems with short growing seasons are shifting to reduced tillage and overhead irrigation to stay economically viable, but more research is needed on the impact of soil health practices such as crop diversification, reduced tillage, and livestock integration on soil physical and chemical properties in these systems. A multi-year study from 2014-2020 in the Bighorn Basin of Northwest Wyoming used a three-crop rotation (diversification... T. Vance, V. Crowe, J. Norton |
9. Adopting Quinoa in Eastern Idaho – An Investigation of Agronomic PracticesQuinoa production area has been increasing rapidly in eastern Idaho in recent years. However, best management practices for quinoa production are yet to be determined in this area. Field experiments were thus conducted at two locations (e.g., Aberdeen and Tetonia) in eastern Idaho from 2016 to 2018 to evaluated agronomic practices for quinoa production. More successful quinoa production was demonstrated in Tetonia, where air temperature is mostly below 30oC during the summer. In contrast,... X. Liang, R. Yang |
10. Belowground Ecological Interactions For Improved Plant Health, Nutrition And Environmental Quality In Agricultural ProductionPlant roots are in constant interaction with the myriad of organisms that inhabit the soil. Microbe-root associations are important for a plant’s successful establishment in an environment as they directly or indirectly support nutrient cycling, nutrient uptake and defense from abiotic and biotic stressors. Therefore, managing these interactions offers a great opportunity for improving the efficiency and sustainability of agricultural production by improving plant nutrient uptake,... C. Lazcano, E. Boyd |
11. Struvite Phosphorous Fertilizer on Sugar BeetSugar beet is very sensitive to P deficiency early in the growing season. Crystal Green is a struvite phosphorus (P) fertilizer source that may uniquely enhance uptake in sugar beet. In this study, we examine the effect of struvite applied to sugar beet and compare the results against the use of traditional monoammonium (MAP) fertilizer and a control. There was a significant increase in response to MAP over the control for both total and sugar yield. The struvite based fertilizer had an additional... J. Fisher, E. Woolley, J. Svedin, B. Hopkins |
12. Nitrogen Management in Small Grains After AlfalfaSmall grains are commonly grown following alfalfa in Utah and the Intermountain West, especially during drought years as small grains require less irrigation than corn. Several studies across the country have shown that corn following alfalfa rarely needs N fertilizer, yet relatively few have evaluated the N needs of small grains. Furthermore, research on the N needs of small grains grown as forage vs. grain are even more sparse. The objectives of this research are to quantify the... C. Pound, M. Yost, E. Creech, G. Cardon, K. Russell, D. Despain, J. Gale, K. Heaton, B. Kitchen, M. Pace, S. Price, C. Reid, M. Palmer, M. Nelson |
13. Struvite Phosphorus Fertilizer on PotatoPotato (Solanum tuberosum L.) is a staple in the global economy and on the dinner table. It has an unusually high demand for phosphorus (P) due to its shallow, inefficient root system. Most P fertilizers are water soluble, but then precipitate quickly—potentially resulting in poor plant uptake. Crystal Green (a struvite based fertilizer) is acid soluble, but not water soluble. In theory, it remains undissolved until plant roots exude acids— potentially avoiding the precipitation... R. Woolley, J. Svedin, E. Woolley, B. Hopkins |
14. 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 |
15. Preliminary Assessment of the Solvita-CO2 Test in Characterizing Management Effects on Soil Biological Activity in Some Soils of HawaiiThe health of agricultural soils depends to a great degree on management practices that promote soil organic matter accumulation. While total soil organic carbon (C) is the standard measure of soil organic matter, it changes slowly and does not provide a sensitive enough test to assess short term management effects on soil health. However, a key indicator of healthy soil is potential biological activity, which can be measured rapidly with soil testing via short-term carbon (C) mineralization following... J. Deenik, M. Loo |
16. Digital Tools to Improve Sustainable Agriculture PracticesVisualizations have been shown to promote learning and understanding and to aid in analysis and problem solving. Many concepts in agriculture are well suited to demonstrations that are used in classroom settings or part of training events. However, many demonstrations are difficult to seed in a large setting, or take more time than can be allotted. A series of demonstrations were either filmed or created in animation to provide a digital means by which trainers could more easily train their students,... R. Flynn, J. Walworth, J. Davenport, A. Ulery, D. Bloedel, J. Gleason |
17. Nitrogen Mineralization of Dairy Manure in a Calcareous Soil Under Field ConditionsUnderstanding N transformations in fields receiving dairy manure applications is an important component of managing this nutrient source to maximize crop profitability and reduce environmental damage. The objective of this study was to determine the net N mineralization from field applied dairy cow manure to a Portneuf silt loam as affected by application rate, application frequency, and naturally fluctuating temperatures throughout the growing season. This study was conducted in a field located... D. Graybill |
18. Creating Prescription Variable Rate Irrigation and Fertilization Zones: Water and Nutrient Management InteractionsVariable rate irrigation (VRI) and variable rate fertilization (VRF) technologies allow irrigation and fertilization rates to be spatially customized. VRF is widely adopted, but VRI is an emerging technology with minimal adoption. As water is often the driving force in nutrient cycling, our overall objectives are to evaluate VRI influences on VRF and vice versa; and to combine these technologies to significantly increase crop yield and quality, conserve water, and minimize environmental impacts... J. Svedin, N. Hansen, R. Kerry, R. Christensen, B. Hopkins |
19. Developing a Soil Test Kit for Extension ProgrammingSoil and horticulture Extension programs are enhanced by hands-on and interactive activities. Readily available and inexpensive soil test kits can be useful in Extension programming in the classroom and the field. With the addition of a few extra supplies and tools, a complete kit can be created for Extension educators to use in horticulture and soil management programming. Five soil test kits from different manufactures were evaluated for both ease of use and accuracy. All kits included... C. Youngquist, J. Norton, J. Harsh |
20. Precision Sensing for Improved Wheat ProductionImproving nitrogen (N) use efficiency (NUE) from current 35-40% is important for growers’ sustainability and environmental quality. Unmanned Aerial Vehicles (UAVs) are proposed as an alternative to traditional field scouting for making crop management decisions. Precision sensors and cameras mounted on the UAVs provide high quality images which can be used to make fertilizer recommendations in-season based on crop nutrient status. A study was conducted at 5 locations in Southern Idaho in... O. Walsh, J. Marshall, J. Mcclintick-chess, S. Blanscet, C. Jackson |
21. Plant Available Silicon Application in Winter WheatMany studies throughout the world has shown that various crops have positively responded to silicon (Si) application in terms of plant health, nutrient uptake, yield, and quality. The study’ objective was to evaluate the effect of Si application rate and time on winter wheat growth and development, grain yield and grain quality. Results suggest that application of plant available silicon at 50% rate at either emergence or Feekes 5 appears to be more advantageous in terms of winter wheat... O. Walsh, J. Mcclintick-chess, S. Blanscet |
22. Response of Spring Wheat to Varied Nitrogen and Water ApplicationsThis study’s objectives were to 1) determine the minimum N and water requirements for optimum wheat grain yield and quality; 2) develop a sensor- based system for identifying – and distinguishing between – N and water stress; 3) produce grower recommendations based on the developed model; and 4) improve grower adoption of efficient water and N application practices and enhance grower understanding of sensor-based technologies. This was the first year of the study, project will... O. Walsh, J. Torrion, X. Liang, J. Mcclintick, S. Blanscet |
23. 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 |
24. Phosphorus and Organic Acid Bonding Impacts at Varying Soil pHPhosphorus (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 |
25. Nitrogen Nutrition Impact on Incidence of Rhizoctonia Infection of Agrostis StoloniferaCreeping 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 |
26. 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 |
27. Evaluation of Nitrogen Gas Loss from Polymer Coated and Polymer Sulfur Coated UreaPrevious 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 |
28. Sensor-based Technologies for Nitrogen Management in Spring WheatCrop 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 |
29. Evaluation of Micro-carbon Technology-based P Fertilizer, Super Phos®, in Spring WheatSuper 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 |
30. Environmentally Smart Nitrogen Performance in Northern Great Plains’ Spring Wheat Production SystemsField 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 |
31. Liquid N Fertilizer Evaluation in Spring WheatSeveral 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 |
32. 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 |
33. Nitrogen Transformations in Flooded Agroecosystems: a Case Study with Taro (Colocassia Esculenta)Wetland agriculture covers an estimated 170 million ha and contributes significantly to global food supply. Nitrogen fertilizers are subject to numerous potential transformation pathways in flooded systems. The present research was focused on improving our understanding of N transformations in a flooded agricultural system by addressing the following two broad objectives: 1) determine whether the presence of anammox bacteria and its activity contribute significantly to N losses, and 2) evaluate... J. Deenik, C. Penton, B. Popp, G. Bruland, P. Engstrom, J. Mueller, J. Tiedje |
34. Climate Change and Nutrient ManagementClimate change models for the intermountain region of eastern Oregon and Washington project warmer and wetter winters with warmer and drier summers. Crop response to the projected climate change conditions were estimated using CropSyst. The anticipated climate changes and increasing CO2 levels are projected to result in greater yields of winter wheat with relatively small changes in yields of spring wheat, potatoes and apples. Greater yields will require increased nutrient supply and increased... S. Petrie |
35. Polymer Coated Urea (Duration) in Turfgrass: Impacts on Mowing, Visual, and Loss to EnvironmentFall 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 |
36. Boron Fertilization of Chile Pepper Under Greenhouse ConditionsMany chile (Capsicum annuum) growers apply boron (B) without knowing if B is actually needed. The application of B has been suggested to improve specific conditions that limit chile productivity such as alleviating blossom-end rot. Two varieties of chile were grown (159 days) under greenhouse conditions in silica sand and irrigated with seven levels of B (no B, 0.025 mg L-1, 0.05 mg L-1, 0.1 mg L-1, 0.25 mg L-1, 0.5 mg L-1, 1.0 mg L-1) and complete nutrient solution. Leaf B increased linearly... W. Lindemann, R. Flynn, C. Carr, R. Steiner |
37. The Use of Biochar As a Fertility Amendment in Tropical SoilsBiochars made from modern pyrolysis methods have attracted widespread attention as potential soil amendments to improve plant productivity in the infertile soils of the tropics. Feedstock and pyrolysis conditions affect the physico-chemical properties of biochar with important implications for soil fertility and plant growth. Specifically, biochar volatile matter (VM) significantly affect soil inorganic nitrogen (N) status and ash content impacts soil elemental composition and pH. This paper highlights... J. Deenik, T. Mcclellan |
38. Biochar Usage: Pros and ConsSoil fertility benefits of charcoal application have been reported as early as 1847 indicating that plant nutrients are sorbed within charcoal pores. The use of biomass-derived black carbon or biochar, the solid byproduct from the pyrolysis processing of any organic feedstock, has garnered recent attention as a potential vehicle for carbon sequestration and a beneficial soil conditioner. However, most of the past biochar research has focused on improving the physico-chemical properties of tropical... R. Lentz, J. Ippolito, K. Spokas, J. Novak, H. Collins, J. Sterubel |
39. Waxy Barley: N Applications for Yield, Beta-glucan, and ProteinNitrogen fertilizer (N) management was evaluated for growing irrigated waxy barley for higher protein and beta-glucan soluble fiber content. A local company has proposed the building of a barley fractionation plant to capitalize on these value-added traits. Salute and Merlin, two spring waxy barley cultivars, were fall-planted to compare yield and quality under different N treatments applied in late winter and at heading and to evaluate ethephon to reduce lodging. Fairly normal winter weather... S. Norberg, B. Brown, C. Shock, A. Ross, P. Hayes, J. Rey |
40. 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 organic... A. Ulery, R. Flynn, R. Walser, M. Weiss, S. Guldan |
41. 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 burned... R. Koenig, C. Proctor, W. Johnston, C. Golob |
42. 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 soil... D. Moberg, D. Sullivan, R. Johnson |
43. 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 (Fecal... R. Yost, R. Pattnaik, G. Porter |
44. 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 was... S. Petrie, S. Albrecht, D. Long |
45. 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 March,... A. Ross, C. Saint pierre, C. Peterson, J. Ohm, M. Verhoeven, M. Larson, B. Hoefer |
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 grasses—... R. Valencia-gica, R. Yost, G. Porter, R. Pattnaik |
47. 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 |
48. 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 experiment... F. Yin, C. Seavert, J. Bai |
49. 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 |
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. Performance of Public and Private Fertilizer Recommendations for Corn, Alfalfa, and Small GrainsThere are many sources that growers utilize to determine fertilizer needs for crops such as private and public labs, crop advisors, and fertilizer dealers. In many cases, these sources provide recommendations for a specific crop that can vary greatly, and the resulting fertilizer and application rates recommended can lead to large differences in costs for the grower. Evaluating the effectiveness and economics of current fertilizer guidelines and recommendations will help growers to make better-informed... M. Yost, M. Baker, J. Gale, E. Creech, G. Cardon |
52. Evaluating Zinc Requirements of Corn, Small Grains, and AlfalfaMany growers and crop advisors in the Intermountain west have recently reported Zn deficiencies in major cereal and forage crops. Further, many common fertilizer blends now include Zn. Most Zn fertilizer guidelines indicate that 5-10 lbs of Zn per acre should be applied when critical soil test Zn levels are less than about 0.8 ppm Zn. These guidelines in Utah and many other states in the region were developed decades ago and need to be reassessed. Therefore, we established Zn response and rate... M. Yost, M. Baker, J. Gale, G. Cardon, E. Creech |
53. 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 |
54. A Single Nutrient Source Hydroponic Solution: pH BufferingMES (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 |
55. 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 |
56. Impact of Variable-Rate Nitrogen on Potato Yield, Quality, and ProfitNitrogen 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 |
57. Irrigation Management and Drought-tolerant Genetics on Nutrient UptakeAlfalfa is exceptional at obtaining nutrients from the soil with its deep tap root. However, with its ability to consume vast amounts of phosphorous and potassium more is used than what is made available each year. This results in the need of nutrient management plans. With the continuing of the drought, nutrient management becomes more difficult. Irrigation management, drought tolerant genetics, and sprinkler technology can play an important role in nutrient management and affect financial outcomes... D. Boren, M. Yost, T. Sullivan |
58. Nutrient Management for Semi-arid Cannabis ProductionThe industrial hemp (Cannabis sativa L.) industry rapidly emerged in Utah in 2019 with nearly 480 new hectares of hemp production. Production declined and stabilized during 2019-2022 due to low returns in a flooded pharmaceutical market. Though small and specialized, the hemp production industry is still viable in Utah and surrounding states. Many questions remain on optimal production practices for this new and potentially high-value crop. Research throughout the United States... T. Sullivan, M. Yost, D. Boren, E. Creech, B. Bugbee |
59. Nitrogen Fertilizer Rate and Timing Implications for Malt, Food, and Feed Barley Production in Southern IdahoNitrogen 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 |
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. 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 P... C. Rogers, Z. Simpson, J. Mott, P. Kleinman |
62. 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 type... K. Deep, M. Yost, J. Williams, B. Hopkins, G. Cardon, B. Black |
63. 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 information.... E. Flint, M. Yost, B. Hopkins |