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1. The Fertilizer Recommendation Support Tool (FRST) Initiative: National Survey on Soil Fertility Recommendations and Correlation/Calibration DatabaseSoil fertility testing is an integral tool used in nutrient management planning, providing information needed to determine where nutrients are required and how much to apply. While a great deal of effort has been successfully invested in standardizing soil test methods in the U.S. over the last few decades, up-to-date correlation/calibration studies are lacking in many states. In most cases, soil test correlation/calibration efforts lead by land-grant universities are on a state-by-state or lab-by-lab... S.E. Lyons, J.T. Spargo, D.L. Osmond, A.W. Pearce, N.A. Slaton, D.K. Arthur, P.J. Kleinman, J.M. Mcgrath |
2. Evaluation of Lime Requirement Estimation Methods for Oregon Agricultural SoilsSoil testing labs in the Pacific Northwest are considering non-hazardous alternatives to the Shoemaker-McLean-Pratt (SMP) buffer method for lime requirement estimation (LRE). While alternative LRE methods have been adopted in other parts of the U.S., they have not been evaluated for Oregon soils. The goal of this study was to evaluate several LRE methods for agricultural soils from western and eastern Oregon, applying the lime incubation method for actual lime requirement. Twenty-four acidic... C. Evans, A. Moore, D. Sullivan |
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. 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 |
5. 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 |
6. Developing a Soil Health Assessment Framework for Specialty Crop Systems and Soils of Washington StateTo ensure productive soils, agricultural sustainability, and food security, it is vital to maintain and improve soil health. However, over the decades, intensive agricultural practices have led to a decline in soil health. While most of these intensive agricultural practices negatively affect soil health, research has shown that it is possible to resuscitate soils with practices such as over cropping, and crop rotation. Much of the research on soil health in the US has been done in agronomic systems... K.A. Sarpong, M. Mcilquham, L. Michel, D. Griffin |
7. Cover Crop Suitability for High Altitude Specialty Crop Organic Food ProductionThere is a growing interest in certified organic, specialty crop food production. With a larger population demanding organic products and organic products offering a higher premium for the producer, farmers are exploring the transition to organic farming. Organic producers in southeatstern Wyoming face multiple challenges in environments with high elevation, low precipitation, and have a short growing season. These challenges include management of persistent weeds, maintaining biodiversity, and... E. Moore, U. Norton |
8. Improving Corn Nitrogen Management Recommendations in the Northwest U.S.The current nitrogen (N) fertilizer recommendations for corn in the Northwest U.S. were developed from limited research (14 potential site-years) in the 1970’s and 1980’s. New data is needed to improve N fertilizer recommendations. Between 2010 and 2017, 17 N rate studies were conducted. Fifteen site-years were conducted for corn grain and 9 site-years for corn silage. Research was conducted on diverse soil types, tillage systems, irrigation systems, and... D.D. Tarkalson, D.L. Bjorneberg |
9. Refining Nitrogen Management for Organic Broccoli ProductionSpecialty organic fertilizers used in organic vegetable production are expensive. So, from environmental and economic perspectives, growers want to maximize nitrogen (N) fertilizer use efficiency by the crop. This research was conducted to (1) determine sufficient N fertilizer rates for organic broccoli, (2) evaluate the efficacy of a specialty organic fertilizer (feather meal; 12-0-0), and (3) confirm the effectiveness of midseason soil nitrate analyses (0-30 cm) in determining appropriate sidedress... D. Sullivan, R.E. Peachey, A. Donaldson |
10. Long-term Soil Profile Acidification: Obvious and Hidden DangersSoil acidification is occurring in the dryland farming region of the Northwest. Historically, soil acidification in the surface foot has been characterized; however, potential acidification of subsoil is unknown. We examined soil acidification for soil profiles (0 to 5 ft) at the R.J. Cook Agronomy Farm (92 ac) for 17 years following conversion from conventional tillage to continuous No-tillage (NT). Surface soil depths (0-12 in) acidified under continuous NT to below 5. Surprisingly, subsoil... D. Huggins, S. Shiwakoti |
11. Is Residue Management an Important Factor in the Soil Health of Perennial Grass Seed Production Systems?Residue management in agricultural systems is a crucial pathway of nutrient and organic matter flow and is predicted to affect soil health indices. In Western Oregon, perennial grasses for seed are a major crop, occupying roughly 150,000 ha in the Willamette Valley. Current estimates are that 80-85% of producers remove straw residue, exporting more than 650,000 US tons of straw annually. The primary objectives of this study were: i) evaluate soil health outcomes under residue retention and removal... B. Verhoeven, A. Moore, D. Sullivan, M. Gonzalez-mateu |
12. Evaluating Cover Crops for Nitrogen Management in a Walnut OrchardCover crops provide numerous benefits in agricultural systems. From increasing soil water storage to reducing fertilizer inputs, quantifying cover crops benefits is crucial in nutrient management, crop productivity, environmental sustainability, and growers' adoption. The goal of this study was to quantify nitrogen (N) and carbon (C) inputs in a walnut (Juglans regia L. 'Chandler') orchard that implemented three cover crop mixtures. The study site was a 5-year-old walnut... D. Zapata, X. Zhu-barker, K. Steenwerth, W. Horwath |
13. Estimating Nitrogen Credits from Organic Matter Sources in OrchardsOrchard crops like almonds can effectively utilize different nitrogen (N) sources to meet the high annual N demand for fruit and tree growth. Different fertilizer formulations like urea ammonium nitrate, calcium ammonium nitrate, ammonium sulfate and potassium nitrate are widely and effectively used, and readily available for uptake. Yet, addressing N availability from organic matter sources in orchards, and in turn estimating appropriate N credits... S.S. Khalsa, P.H. Brown |
14. Humic Products in Agriculture: Potential Benefits and Research ChallengesHumic products have been used in cropland agriculture for several decades, but lack of widespread credibility has restricted their use to small proportions of farmers. To improve the credibility of humic products, we propose future actions to close four knowledge gaps. First, while the capacity of humic products to improve plant growth has been proven in greenhouse and growth chambers, more such work is needed in field conditions, especially to determine the modifying effects on humic... D. Olk |
15. Soil Acidification: Identification, Prevention, Adaptation and RestorationLow soil pH is becoming far more common in Montana soils, with at least 23 counties having at least one field with pH less than 5.5. Soil pH levels in the top 6 inches as low as 3.8 have been measured, resulting in complete crop failure insome locations, yet the problem is highly variable across fields and within soil profiles. Nitrogen fertilizer rates applied above crop nitrogen needs are the largest cause of the acidification. Low soil pH should be verified before managementpractices... C. Jones, R. Engel, S. Ewing, P. Miller, K. Olson-rutz |
16. Managing Soils for CO2 Drawdown: Boon or Boondoggle?Consensus is growing that meeting the goal of a two degree or less global warming will not only require aggressive greenhouse gas emission reductions across all sectors of the global economy, but also active measures to remove CO2from the atmosphere. Among the broader suite of CO2 removal (CDR) strategies, soil C sink approaches have been deemed as being among the most ready for early deployment and having the greatest net environmental benefits. A variety of existing... K. Paustian |
17. Soil Diversity and Agricultural Adaptation Across MicronesiaMicronesia, a sub-region of Oceania, comprises approximately 2,100 small islands belonging to five sovereign nations scattered across 2.9 million square miles of the Western Pacific. A majority of the islands are low-lying, sandy coralatolls, but high volcanic islands and raised limestone islands are major population centers in the region. Palau, in the west, was first settled by seafaring peoples as early as 4000-4500 BP and the colonization of Marshall Islands at the eastern edge... J. Deenik |
18. Polymer Coated Urea and Urea Blends on PotatoPotato (Solanum tuberosum L.) is a globally important crop with significant economic and environmental impacts. Nitrogen (N) has a large impact in both instances. Polymer coated urea (PCU) is a N source with the ability of improving production and the environment. Environmentally Smart Nitrogen (ESN) is a PCU that may reduce the need for continual N application throughout the season. The objective of this research was to evaluate the impacts on potato tuber yield and quality with uncoated... E. Carlock, A. Weigel, T. Searle, T. Hopkins, J. Williams, B. Hopkins |
19. Polymer Coated Urea Impact on Barley Yield and ProteinPolymer coated urea (PCU) is an enhanced efficiency nitrogen (N) fertilizer shown to regulate N release over a season benefiting production and reducing nutrient pollution. The purpose of this study was testing the effect of uncoated and coated urea blends on irrigated barley yield and protein. The study consisted of three N rates applied as all urea or a 50-50 blend of PCU and urea. As expected, N rates increased yields and protein. In general, urea resulted in increased yields with... S. Fahning, T. Searle, A. Weigel, R. Buck, T. Hopkins, B. Hopkins |
20. Cover Crops As A Source Of Plant-Available Nitrogen: Effect Of Residual Soil N And Cover Crop SpeciesFall-planted brassica and small grain cover crops have the potential to serve as catch crops by taking up residual soil nitrogen (N) in the soil. While plant species is often considered when estimating N release rates from cover crop residues, variation in residual soil N is rarely considered. The first objective of this study was to quantify the effect of N fertilizer application rate (to simulate varying residual soil N levels) on tissue N concentrations of several cover... J. Neuman, D. Sullivan, A. Moore |
21. Polymer Coated Urea in Kentucky BluegrassNitrogen (N) is a commonly over-applied nutrient in urban environments. This over-application has led to nutrient pollution of the atmosphere and hydrosphere. The losses of N to the environment can be mitigated with the use of enhanced efficiency fertilizers, such as polymer coated urea (PCU). Some PCU labels state that a single annual application is a best management practice. The objective of this study was to evaluate a PCU compared to monthly applications of ammonium sulfate/urea.... S. Stapley, J. Buss, B. Hopkins |
22. Dry Bean Production in CaliforniaThere are four species and eight market classes of dry beans grown in California. These include lima beans (baby and large, Phaseolus lunatus), common beans (kidney, pink, white, cranberry, black turtle, P. vulgaris), blackeye (cowpea, Vigna unguiculata), and garbanzo beans (chickpea, Cicer arietinum). Dry beans are an important specialty market for California. In 2017, growers harvested 50,000 acres of dry beans valued at $60 million. Lima beans accounted for about... R. Long |
23. 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 |
24. Interpreting Compost AnalysesThis outreach publication is designed for wholesale buyers of compost for resale, nursery managers, public/private landscape managers, farm advisors, and farmers. The publication provides guidance on how to select a laboratory, based on intended compost end use (field application vs. potting soil). Interpretations are provided for laboratory tests available from commercial laboratories, including chemical tests (pH, soluble salt, macro- and micro-nutrients), physical tests... D. Sullivan |
25. Canola Roots of Water and Nitrogen Use Efficiency: New Lessons for PNW Wheat GrowersThe semi-arid inland Pacific Northwest (iPNW) has primarily produced wheat for 125 years due to favorable climate, soils, economics and policy drivers. Shifting drivers over the past decade related to energy, climate change, regional and global markets have created new opportunities for the integration of canola into iPNW wheat-dominated rotations. Traditional wheat grower mindsets required an agronomic reboot, forged by an understanding of canola vs. wheat physio morphology, an explosion of variety... W. Pan, T. Maaz, I. Madsen, W. Hammac, M. Reese |
26. Nebraska Nitrogen Management Present and FutureUniversity of Nebraska faculty have been refining their N rate recommendation procedure since the 1970s. At that time, they introduced a procedure for predicting soil nitrate-N availability and effect on subsequent corn N needs. In the 1990’s this procedure was refined based on 81 state wide N rate experiments. In 2003-2006 it was re-confirmed with 32 state wide irrigated corn trials. The current algorithm is the following: N need (lb/ac) = [35 + (1.2 x EY) - (8 x NO3- N ppm) - (0.14 x EY... C. Shapiro, R. Ferguson, C. Wortmann, T. Shaver, B. Krienke, G. Hergert, B. Maharjan |
27. N Management Tools for Desert VegetablesOver the past two decades studies have been conducted to evaluate diagnostic tools and practices aimed at the development of more efficient N management in desert vegetable cropping systems. In all cases initial studies were conducted in small plots at University Research Farms. However, practices that were found to be promising were scaled up into large experiment-demonstration in commercial production fields. Studies show that while tissue tests were often reasonable diagnostic tools for N deficiency... C. Sanchez |
28. Measuring Ammonia Loss Using Field-scale and Laboratory TechniquesFollowing the surface application of urea to soil, there is the potential for nitrogen (N) loss from ammonia (NH3) volatilization until sufficient rain or irrigation has moved it into the soil. Many studies measuring NH3 loss have used laboratory and microplot field studies. The limitation of these techniques is that they do not represent NH3 loss under natural conditions because enclosures alter air movement, humidity, and soil and air temperature inside the chambers. However, they... A. Heinrich, D. Sullivan |
29. 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 |
30. 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 |
31. Cover Crops for Hop Production in Semi-arid ClimatesTilling interrows to control weeds is a common practice in hop production, especially in the Yakima Valley of Washington which receives 8 inches average annual precipitation and produces 74% of US hops. Dry, tilled interrows leaves topsoil prone to erosion and decreases soil organic matter over time. The goal of this three-year study is to determine cover crop species that would be profitable weed control alternatives to tillage for hop producers in semi-arid climates by providing ground cover,... S. Del moro, J. Davenport, C. Jones |
32. 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 |
33. 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 |
34. 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 |
35. 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 |
36. Minimizing Nitrogen Inputs While Optimizing Verdure and Growth of Kentucky Bluegrass with Polymer Coated UreaNitrogen (N) fertilizer increases turfgrass verdure but also increases maintenance costs due primary to mowing. A two-year fertilization study was initiated April 2014 at two established Kentucky bluegrass sites with sand and loamy sand constructed field soils in Provo, UT. A grower’s standard practice (GSP) of urea split applied monthly was compared to blend of uncoated and polymer coated urea (PCU). The PCU was applied in 1, 2, or 3 split applications. The dual application applied at 50,... J. Buss, J. Gish, B. Hopkins |
37. Stratified Soil pH Identification ProjectColumbia County Washington is in the foothills of the Blue Mountain Range and the edge of the Palouse wheat country. The soils of the farming region are mostly a rich silt loam having a rainfall ranging from 12 inches to 25 inches north to south respectively with elevations from 1000 to 3200 feet. About 90% of the cropping systems have adopted conservation tillage, direct seeding or no-till, which has been good for the management of soil erosion. In April 2006, intense soil sampling (1 cm increments)... P. Carter, T. Bruegman |
38. 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 |
39. Ammonia Volatilization from Urea Vs. Alternative Nitrogen FertilizersSubstantial ammonia (NH3) volatilization can occur from surface application of urea on sandy soils with low pH buffering capacity such as those in the semi-arid Columbia Basin. Previous studies have reported loss of up to 60% of urea-N as ammonia on these soils. The objective of this study was to quantify ammonia loss per acre for urea and for alternative N fertilizer products, including: sulfur-coated urea (SCU), urea coated with NBPT urease inhibitor (urea + Agrotain), ammonium sulfate... S. Del moro, D. Sullivan, D. Horneck |
40. Moving Toward Sustainable Cropping and Grazing SystemsDuring the 1980’s Burleigh County, North Dakota farmers and ranchers historically managed their operations in a traditional manner of tillage dependent cropping systems with simplified rotations, no cover crops, high input costs, and season long grazing. In the early 1990s, the Burleigh County Soil Conservation District Supervisors formed a team and began implementing no-till cropping systems with some crop diversification and simple cover crop mixtures. Native Rangeland was established... J. Fuhrer |
41. Manganese Nutrition and Photosynthesis of ‘Pawnee’ PecanSouthwestern pecan (Carya illinoinensis) orchard soils are alkaline and calcareous which negatively affects manganese (Mn) availability for root uptake. Mn is essential for photosynthesis because of its roles in the photosystem II complex and chlorophyll biosynthesis. Levels of leaf Mn for optimum photosynthesis (Pn) in pecan is not known. Our objective was to characterize the relationship of widely different leaf tissue Mn concentrations on Pn. The experiment was conducted from 2011 through 2012... R. Heerema, J. Sherman |
42. Nitrogen Cycling and Fertilization in Legume Inclusive Cropping SystemsAmong other benefits, legumes contribute nitrogen (N) to subsequent crops. However, predicting the impact on yield and the timing of the N release is difficult. Regardless, adjustments in the N recommendation need to be made to avoid yield and crop quality problems, as well as negative environmental and social issues. Ideally, a reduction of pre-plant/early season N fertilizer is made based on field research. Two possible approaches are used, namely the Fertilizer Replacement Value (FRV) or the... B. Hopkins, J. Stark |
43. 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 |
44. Chloride Effects on Nitrogen Uptake in Potato ProductionPotassium (K) can be supplied by potassium chloride (KCl) or sulfate (K2SO4) salts. Past research has shown that potatoes can take up and accumulate large amounts of chloride (Cl). Plant uptake of Cl can sometimes reduce petiole nitrate-N (NO3-N) concentration and it may have other effects on potato tuber yield and quality. In contrast, sulfate-S (SO4-S) typically does not compete strongly with NO3-N for plant uptake. This research was designed to evaluate the effect of Cl application on petiole... D. Sullivan, S. Light, D. Horneck |
45. Applying a Phosphorus Risk Index in a Mixed-use Mountain WatershedSurface waters in the Wallsburg, UT watershed have been identified as a relatively high contributor of phosphorus (P) to nearby Deer Creek Reservoir. Identifying the major contributors of P is critical for developing effective management practices. Phosphorus Risk Indices have been widely developed as a tool to identify areas with high risk of P movement, but these tools have mostly been applied to watersheds dominated by agricultural land use. While agriculture is often a source of nutrient pollution,... A.W. Pearce, J. Johns, D. Robinson, N. Hansen |
46. Summarization of 471 Field Comparisons of Avail®Phosphorus (P) is a commonly deficient essential nutrient required for crop production. Economic, environmental, and conservation issues have motivated significant efforts to enhance fertilizer efficiency. AVAIL® is a specialty fertilizer product with claims of enhancing P use efficiency to potentially increase crop yield and quality. There have been at least 471 field comparisons to evaluate the effectiveness of AVAIL with a wide variety of crops. The objective of this summarization... B. Hopkins, K. Fernelius, M. Pryor |
47. Turf Response to Reduced Rates of Polymer-coated UreaPolymer-coated urea (PCU) is a controlled-release fertilizer which can enhance nitrogen (N) use efficiency (NUE), reduce N pollution, reduce the need for repeated fertilizer applications, and reduce turfgrass shoot growth and associated costs. A PCU fertilizer rated for 120 d was applied at 50, 75, and 100% of the recommended full rate and compared to an unfertilized control and urea, applied either all at once or split monthly at the full recommended rate. Spring applied PCU showed no initial... B. Hopkins, C. Ransom, M. Ruth, T. Blair, L. Sutton, D. Bradshaw, K. Campbell |
48. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency and Yield Response in Crop PlantsPhosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past seven years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This paper will be a review of a portion of that data. Studies comparing CBP to ammonium polyphosphate (APP) and monoammonium phosphate (MAP)... B. Hopkins, T. Blair, J. Selman, C. Ransom, T. Hopkins |
49. Nitrogen Budgeting for Organic ProductionNitrogen management for high value vegetable crops under organic management is challenging. Organic systems rely on N mineralization processes in soil to deliver nitrate-N in adequate amounts with appropriate timing. The traditional nutrient management planning process (checkbook method: matching nutrient supply and demand over a production cycle) contains too many assumptions for accurate forecasting of plant-available N supply for organic systems. Organic fertilizers fall into three... D. Sullivan |
50. 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 |
51. 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 |
52. Phytomanagement of Soluble Selenium and Production of Biofuel and Biofortified New ProductsIn many areas of the western US, excessive concentrations of soluble selenium (Se) in the environment can cause Se toxicity to biological organisms. The use of green plants to manage the soluble Se content in soils by plant uptake and biological volatilization has been considered as a cost-effective strategy. Importantly, the development of economically feasible remediation systems will encourage more widespread implementation of an integrated phytomanagement technology. The objective of this... G. Banuelos |
53. Using Irrigation Nitrogen Credits for Grain CropsNitrogen contamination of surface and groundwater is not uncommon in many areas of the U.S. and Colorado is no exception. Nitrate-nitrogen (NO3-N) in groundwater is the most common form of plant available nitrogen (N), especially in shallow, alluvial aquifers in areas with intensive irrigated agriculture. When utilized as a primary irrigation water supply, this nitrate can contribute a significant portion of a crop’s N supply. Crediting water nitrate is part of Colorado N fertilizer recommendations... T. Bauder, R. Waskom |
54. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency in Crop PlantsPhosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past five years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This presentation will be a review of that data. Studies comparing CBP to ammonium polyphosphate (APP) applied to soil show season-long increases... B. Hopkins, T. Blair, M. Hill, C. Ransom |
55. 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 |
56. Inhibitors, Method and Time of Nitrogen Application for Improved Winter Wheat Production in Central MontanaThe contribution of nitrogen (N) fertilizer to boost yield and improve quality is unquestionable. Inefficient use of applied N is economically significant and environmentally unsafe. Ammonia loss can exceed 40% of applied N. Nitrogen leaching is polluting wells. Use of urease and nitrification inhibitors along with appropriate timing and method of nitrogen application can reduce nitrogen loss, improve yield and quality of wheat. This experiment investigated the effect of timing and method of N... Y. Mohammed, T. Jensen, J. Heser, C. Chen |
57. 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 |
58. Use of Non-replicated Observations and Farm Trials for Guiding Nutrient Management DecisionsReplication or repetition is the means by which experimental error is estimated in replicated trials. In farm trials, it is sometimes not possible to replicate demonstration and test plots due to manageability and costs. In these situations, non-replicated observations and on-farm trials are used. In addition, nutrient response studies are often needed to calibrate the fertilizer requirement of a field. In this paper, we will define on-farm trials and observations, discuss the nature and underlying... S. Machado, K. Girma |
59. 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 |
60. 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 |
61. Development and Use of the OSU Organic Fertilizer and Cover Crop CalculatorFarm advisory visits in Oregon highlighted the need for decision tools to help farmers and agricultural professionals estimate nitrogen (N) mineralization from organic fertilizers and cover crops, design balanced fertilizer plans and identify the most cost effective nutrient management options. Laboratory and field research was conducted to develop N mineralization models for organic fertilizers and compost based on the total percent N. Field methods for estimating cover crop biomass and total... N. Andrews, D. Sullivan, J. Julian, K. Pool |
62. Highbush Blueberry Response to Compost and SulfurHighbush blueberry is adapted to soils with high organic matter and acidic pH, and it is often grown in Oregon with coniferous sawdust as a soil amendment or mulch. Composts could provide an alternative to sawdust, but acidification is needed to overcome high pH. Our objectives were to (i) predict the quantity of acidity needed to reduce compost pH to 4.8 (ideal for blueberry), (ii) determine compost characteristics suited for blueberry, and (iii) evaluate plant growth response and soil pH response... D. Sullivan, R. Costello, D. Bryla, B. Strik, J. Owens |
63. 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 |
64. Improving Phosphorus Use Efficiency with Carbond PPhosphorus (P) fertilizer is integral for maximizing crop production and is used abundantly to achieve desired yields. However, reduction of P fertilizer is warranted, as it is the primary source of nutrient pollution in surface waters (eutrophication leading to hypoxia) and is derived from non-renewable mineral resources. Two research studies were conducted in 2009 to evaluate a new fertilizer product, Carbond® P against traditional fertilizers ammonium polyphosphate (APP) and monoammonium... B. Hopkins, B. Webb, M. Hill, C. Ransom |
65. Choosing Your Nitrogen Fertilizers Based on Ammonia VolatilizationUntil recently we have not been able to measure ammonia volatilization without impacting the surrounding environment. In the past we have used closed chambers with acid traps. These closed chambers did not reflect surrounding weather conditions, at the minimum both temperature and wind were influenced. The use of the vertical flux method allows ammonia in the air to be monitored and modeled to reflect ammonia loss without any interference of the surrounding environment. ... D. Sullivan, D. Horneck, J. Holcomb, G. Clough |
66. Ammonia VolatilizationLittle work has been reported on the loss of ammonia from soils where fertilizers have been applied in an undisturbed environment. There are a multitude of studies that have used a chamber of some sort to estimate ammonia loss. The use of a chamber of some sort means that the environment has to be altered making the data derived suspect when translated into a loss number such as kg/ha. The advent of passive vertical flux method by Wood et al., 2000 at Aubrn University in Alabama, allows for the... J. Holcomb, D. Horneck, G. Clough, D. Sullivan |
67. Influence of Dairy Manure Applications on Corn Nutrient UptakeCorn silage is the predominant crop in Idaho used for recovering phosphorus (P) that has accumulated in soils from dairy manure applications. However, little is known about how much phosphorus and other nutrients are being recovered under Idaho conditions. The objective of the study is to estimate phosphorus removal by irrigated corn silage crops cultivated throughout Southern Idaho with variable soil test P concentrations, and to identify effects of increasing soil test P on potassium (K), calcium... A. Moore, B. Brown, J. Ippolito, S. Hines, M. De haro marti, C. Falen, M. Chahine, T. Fife, R. Norell |
68. Predicting Plant-available Nitrogen Release from Cover Crop ResiduesImproved methods are needed to estimate the timing and amount of plant- available N (PAN) release from cover crops. The OSU Organic Fertilizer and Cover Crop Calculator, a downloadable spreadsheet tool, assists agricultural professionals in estimating N fertilizer replacement value of organic inputs. We conducted a series of laboratory incubations with cover crop biomass incorporated into soil to determine: (i) speed of PAN release, (ii) amount of PAN release, and (iii) robustness of the OSU Calculator... D. Sullivan, N. Andrews, R. Datta, K. Pool |
69. Polymer Coated Urea: Impacts on Water/air Quality with Surface Applicaton to Permanent SodNitrogen (N) is the most commonly used fertilizer and is essential to sustain the world’s populations. However, inherent inefficiencies in the soil-plant system result in losses of N to air and water, which can result in environmental quality problems. Two permanent sod turfgrass sites were fertilized with coated and uncoated urea and compared to an unfertilized control at 224 lb-N/ac. The polymer coated urea (PCU) was Duration 45 CR®. Fertilization resulted in increased growth and verdure... B. Hopkins, J. Lemonte, J. Summerhays, V. Jolley |
70. Alfalfa Tissue and Seed Yield Response to Applied BoronAlfalfa seed production can be limited by low boron (B) and information on tissue tests used for indicating B needs is lacking. Alfalfa seed trials were conducted in 2007 and 2008 in a silt loam to compare B concentrations in reproductive tissues (buds and flowers) with more traditional upper stems for reflecting available B. Factorial combinations of mid April knifed-in B (main plots) at three rates and four subplot foliar B timing treatments (non-treatment or 0.4 lb B/A at bud, flowering, and... B. Brown |
71. Nitrogen Timing for Boot Stage Triticale Forage Yield and Phosphorus UptakeOptimal N timing for boot stage winter triticale forage production and phosphorus (P) removal is not well established. Irrigated winter triticale in low and relatively high Olsen P soil was treated with six rates of fall pre-plant N and two rates of late winter N at Parma in 2006 and 2007. Triticale boot stage biomass, protein, nitrate-N, P concentrations, and P uptake and were determined. Fall preplant N increased forage production and frequently produced more boot stage triticale biomass. It... B. Brown |
72. 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 |
73. Biochar Volatile Matter Content Effects on Plant Growth and Nitrogen Transformations in a Tropical SoilBiochars made from modern pyrolysis methods have attracted widespread attention as potential soil amendments with agronomic value. A series of greenhouse experiments and laboratory incubations were conducted to assess the effects of biochar volatile matter (VM) content on plant growth, nitrogen (N) transformations, and microbial activities in an acid tropical soil. High VM biochar inhibited plant growth and reduced N uptake with and without the addition of fertilizers. Low VM charcoal supplemented... J. Deenik, A. Mcclellan, G. Uehara |
74. Economics of Fertilization Under Site-specific Management ZonesSite-specific management of crop fields using variable rate application of inputs to manage in-field variability has now been around for over 15 years. However, the degree to which site-specific management strategies increase farm profitability is not well established. The objectives of this study were: to compare uniform and variable-rate Nitrogen (N) management strategies across productivity level site-specific management zones and to identify the most profitable N management strategy. This... R. Khosla, D. Westfall, W. Frasier, B. Koch |
75. Residual Soil Nitrate and Potato Yield with Polymer Coated UreaPotato (Solanum tuberosum L.) requires steady, but not excessive nitrogen (N) supply for maximum tuber yield, size, and solids, as well as minimal internal and external defects. Although more costly and labor intensive than dry broadcast applications, growers typically apply a majority of N via fertigation. A controlled release N fertilizer, polymer coated urea (PCU), is a possible alternative to this growers’ standard practice. A newly formulated PCU may meet plant demand... B. Webb, B. Hopkins, J. Lemonte, T. Taysom, V. Jolley |
76. Elemental Sulfur with Iron: Kentucky BluegrassIron (Fe) is known to improve greenness of Kentucky bluegrass (KBG; Poa pratensis L.), although applications are relatively costly and labor intensive. A new fertilizer material, elemental sulfur impregnated with Fe (ES-Fe), may provide an alternative source of Fe for KBG. The effects of ES-Fe on KBG was evaluated comparing 55 lb-Fe ac-1 ES-Fe to ferrous sulfate (FS) at the same rate and chelated Fe as a foliar (CF) or soil applied (CS) in a glasshouse study. A separate... B. Hopkins, B. Webb, K. Marcroft, R. Christenson, V. Jolley |
77. 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 |
78. Dig It! the Secrets of Soil a Primer on the Smithsonian Soils ExhibitThis past summer the Soil Science Society of America (SSSA) opened an exhibition entitled, “Dig It! The Secrets of Soil”. It resides at the Smithsonian Museum of Natural History in Washington D.C., and represents a huge step forward in our Society’s efforts to educate youth about soils and to pique their interest in studying soils. ... G. Peterson |
79. 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 |
80. Irrigated Small Grain Residue Management Effects on Soil Properties and Nutrient CyclingThe effects of straw removal from irrigated wheat and barley fields on soil properties and nutrient cycling is a concern due to its potential impact on the sustainability of agricultural production. The demand for animal bedding and the potential development of cellulosic ethanol production will likely increase straw demand in the future. Previous reviews addressing changes in soil properties when crop residues are removed focused primarily on rain-fed systems. This paper reviews published research... D. Tarkalson, B. Brown, D. Bjorneberg, H. Kok |
81. 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 Zn... B. Webb, B. Hopkins, J. Ellsworth, S. Barben, B. Nichols, V. Jolley |
82. 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 experiments... A. Bary, D. Sullivan, C. Cogger |
83. 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 furrow... B. Brown, R. Gibson |
84. 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 |
85. 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 plant... J. Davenport, R. Bramley |
86. 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 |
87. 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 |
88. 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 |
89. 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 at... B. Webb, B. Hopkins, J. Ellsworth, V. Jolley, R. Callahan |
90. 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 |
91. 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 two... J. Stark, S. Love, C. Mcintosh |
92. 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 output... D. Sullivan |
93. 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 sides... J. Walworth, A. Pond, H. Nunez, B. Wood, M. Kilby |
94. 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 |
95. 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 |
96. Soil Health in American Sports Fields and Golf CoursesHealthy soils are essential for sustaining the world’s ecosystems and maintaining human lifestyles. The adoption of biological, chemical, and physical analyses to assess soil health is a relatively new concept with a paucity of scientific work assessing how well these tests can predict and influence soil health. Golf and sports turf are arguably the most intensively managed soil systems in the world, including fertilizer and pesticide use. Excess fertilizer and pesticide application can... M. Barnes, B.G. Hopkins |
97. Monitoring Soil Nitrate to Estimate Cover Crop N Contribution in Organic Vegetable Production FieldsOrganic vegetable growers rely on legume cover crops as an economical source of plant-available N. This research evaluated N contributions to summer vegetable crops by cover crops (CC) residues by monitoring soil nitrate (NO3-N) concentrations during the summer crop growing season. Replicated field plots were established with three CC mixes: solo common vetch (V), phacelia + V (PV), and cereal rye + V (RV), plus a winter fallow (F) control in grower fields in the north Willamette Valley... D. Sullivan, N. Andrews |
98. 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 |
99. Biosolids-based Fertilizers as a Nitrogen Source in California Small Grains SystemsSituation/ conditions In response to regulatory and economic pressure, California growers are becoming more familiar with nitrogen budgets. In addition to seeking out ways to improve nitrogen management strategies, growers can possibly benefit by incorporating alternative sources of nitrogen to feed their crops. Liquid injected or pelletized biosolids-based fertilizers from local waste streams and processing facilities are one source that growers are beginning to explore. As... K. Mathesius, D. Geisseler, M. Savidge, M. Lundy, T. Nelson, N. Andersen |
100. The Effects of Calcium Source and Placement on Soil Factors and Wheat Performace FactorsWheat production is a critical component of U.S. Pacific Northwest agriculture, with approximately 80% of the global soft white wheat grain supply originating from this region. Ammonium-based nitrogen fertilizers are widely used on typically alkaline soils in Eastern Oregon dryland production areas by wheat growers. However the nitrification process that biologically converts ammonium to nitrate increases the soil concentration of H+. This process ultimately creates acidic soil conditions, which... S. Ellickson, A. Moore, R. Zemetra, C. Hagerty |
101. 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 |
102. 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 |
103. Helpful or Not?- Biostimulant Use in Corn Silage ProductionThere has been a recent increase in both the availability and marketing of biostimulant products to local producers, particularly to dairymen, in southern Idaho. These products claim to increase yield and nutrient use efficiency while improving soil health on agricultural fields. If these claims are true, the use of these products would ultimately aid in promoting the overall sustainability of Idaho farms. However, there is a lack of objective data to support these claims, leaving producers uncertain... L.R. Schott, S. Hines, J. Packham, G. Loomis, M. De haro marti, C. Willmore |
104. ManureDB: Creating a Nationwide Manure Test DatabaseManure nutrients serve an important role in crop production, however compared with commercial fertilizers there is a lack of standardized information. When exact manure values are not known, manure book values have been referenced. Recent data from midwestern United States (US) labs indicates manure nutrient levels have changed from book values published by Midwest Plan Service (2004) and American Society of Agricultural and Biological Engineers (2005). Manure laboratory analysis has improved... N.L. Bohl bormann, M.L. Wilson, E.L. Cortus, K. Janni, K. Silverstein, L. Gunderson |
105. Soil Greenhouse Gas Dynamics in Response to Dairy Manure Compost in an Almond OrchardApplication of dairy manure compost in soils under almond production may confer benefits such as increased carbon sequestration, improved crop nutrient use efficiency, and reduction of greenhouse gas emissions. Elucidating the mechanisms of greenhouse gas emissions and mitigation is a primary concern in the management of agricultural soils and it is directly linked to nutrient management. Presently, agricultural soils account for 11.2% of U.S. greenhouse gas emissions. Of particular concern is... A. Coyotl, J. Murch, S.S. Khalsa, W.R. Horwath |
106. 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 |
107. 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·ha-1... S. Lukas, S. Singh |
108. 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 interested... B. Hopkins, S.V. Nelson, G. Cardon, J. Lawley, T.J. Hopkins |
109. 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 |
110. 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 |
111. 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 cured,... B. Hopkins, R. Kerr, S.V. Nelson |
112. 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 concentrations... B. Hopkins, G. Bell, S.V. Nelson, R.E. Sannar |
113. 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 |
114. 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 with... C. Sanchez |
115. 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 fertilizer... C. Sanchez |
116. 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 relevant... C. Sanchez |
117. 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 |
118. 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 |
119. 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 pest... P.H. Brown |