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1. 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 |
2. Effects of Lime and Micronutrient Amendments for Acidic Soils of the Inland Pacific NorthwestThe soil pH of agricultural land in the inland Pacific Northwest has dropped precipitously from native soil levels of near 7.0 pH. Changes that were becoming evident in the 1980’s have reached critical levels, leaving tens of thousands of acres of previous prairie soil at pH under 5.0 and unable to grow an increasing number of aluminum-sensitive crops. Some farmers in the region are beginning to use lime application to neutralize soil acidity. However, pH changes and liming can also... R. Wieme, L. Carpenter-boggs, P. Carter, S. Van vleet |
3. 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 |
4. 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 |
5. Effects of Semiarid Wheat Agriculture on Soil Microbial Properties: A ReviewAgricultural management decisions on factors such as tillage, fertilization, and cropping system determine the fate of much of the world’s soils, and soil... J. Norton, H. Rodgers, L. Van diepen |
6. 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 |
7. 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 |
8. Phosphorus Efficiencies of Liquid P Fertilizers as Evidenced by P Adsorption Isotherms of Western Calcareous SoilsThe high levels of free lime or calcium carbonate (CaCO3) in arid Western U.S.A. soils reacts with phosphorus (P) fertilizers to form Ca-P minerals that are not available to plants through P fixation. Enhanced efficiency P fertilizers may potential decrease P fixation. The objective of this study was to identify P fixations levels associated with several enhanced efficiency P fertilizers on a basic soil (pH 8.03) over a 1-, 3-, and 7-day time period, and to use that data to adjust P fertilizer... J. Williams, S. Davis, K. Dabbs |
9. 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 |
10. 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 |
11. Soil Water and Plant Canopy Sensor Technologies to Optimize Water and Nutrient UseIn many respects, agricultural technology is doing things now that were only imagined 20 to 30 years ago. Yet, grower tools that provide information and actionable knowledge on water and nutrient availability still remain a challenge. Clearly, rapid development of data transfer and processing platforms to date has provided rich maps of grower fields with overlays of location-specific information but their utility is still limited by our ability to accurately measure the parameters that are the... C. Campbell, N. Hansen, B. Hopkins, S. Evans, E. Campbell, A. Campbell, L. Rivera, D. Cobos |
12. Irrigation Effects on N AvailabilityIrrigation is necessary for crop production in the western US where the climate ranges from Mediterranean to desert conditions. Management of irrigation can potentially have large effects on crop available N because nitrate-N readily moves with water and because soil moisture affects root activity and the uptake of N. Additionally, fertigation is commonly used to supply N to crops though the irrigation system. More efficient use of N can be achieved by assuring that an irrigation system has a... M. Cahn |
13. 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 |
14. 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 |
15. Improving Nitrogen Use Efficiency of Cool Season Vegetable Production Systems with Broccoli RotationsNitrate leaching in leafy vegetable production in the Salinas Valley, CA is a continuing problem. Increased levels of nitrate in groundwater resources affects the ability of municipalities to access drinking water that meet federal water quality standards. Regulations by the Central Coast Regional Water Quality Control Board are now requiring growers to improve nitrogen use efficiency (NUE) in production fields. In prior studies we found that above ground biomass nitrogen (N) at crop maturity... R. Smith, M. Cahn, T. Hartz |
16. 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 |
17. Cropmanage: an Online Decision Support Tool for Irrigation and Nutrient ManagementVegetable and berry growers on the central coast of California are under growing regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of these crops are the soil nitrate quick test (SNQT) for monitoring soil residual N concentrations and evapotranspiration (ET)-based irrigation scheduling for estimating crop water requirements. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage),... M. Cahn, T. Hartz, R. Smith, B. Noel, L. Johnson, F. Melton |
18. 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 |
19. 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 |
20. Utilizing Low Salt Liquid NPK Fertilizers to Establish Triticale As a Cover CropThe use of cover crops in sustainable agricultural systems is receiving renewed attention. New initiatives in soil health promote cover crops as amanagement tool to improve soil quality and health. Successful establishment of cover crops depends on an adequate soil fertility program. Low salt NPK liquid fertilizers can improve cover crop establishment without concern of the impact of high salt index of some conventional fertilizers. This paper presents some of the success that have been observed... G. Mooso, T. Tindall |
21. 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 |
22. Irrigation and Nitrogen Management Web-based Software for Lettuce ProductionLettuce growers on the central coast of California are under increased regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of lettuce are the quick nitrate soil test (QNST) for monitoring soil mineral nitrogen levels and weather-based irrigation scheduling for estimating water needs of the crop. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage), to facilitate... M. Cahn, R. Smith, T. Hartz, B. Noel |
23. 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 |
24. Nitrogen Dynamics in Conventional, Reduced Tillage and Organic Irrigated Systems: Results of a Four-year Experiment in WyomingSoil nitrogen (N) is critically important for crop production. A field experiment was conducted in eastern Wyoming to evaluate soil mineralizable (mineralized in 14 days incubation) and inorganic N contents as influenced by conventional, organic and reduced-tillage management approaches for cash-crop and forage production in eastern Wyoming. Soil samples were collected from all treatments (2 production systems x 3 management approaches) during 2009-2012 and analyzed for soil mineralizable and... R. Ghimire, J. Norton |
25. Efficient N Fertility and Irrigation Management in Vegetable and Berry ProductionNitrogen (N) fertility and irrigation management for vegetable and berry production has historically been done on an ‘agronomic’ basis, with the sole focus on producing the optimal crop. For these crops N fertilizer and water costs are a small portion of overall production costs, and an even smaller portion of crop value; consequently, these inputs have not been scrutinized as closely as they have been for lower value crops. However, throughout the West concern over environmental water... T. Hartz, R. Smith, M. Cahn |
26. Phosphorus Use Efficiency in Crop ProductionThe limited availability of phosphorus (P) in calcareous and acidic soils can be a major factor that limits crop production. The objectives of this study were to investigate the mobility and availability of P from monoammonium phosphate (MAP), diammonium phosphate (DAP) and ammonium polyphosphate (APP) fertilizers alone and with AVAIL, a fertilizer enhancement product. Two different soil types were used to examine the relationship between P reaction products and available P. Soils were incubated... G. Mooso, T. Tindall, G. Hettiarachchi |
27. 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 |
28. Organic Management Improves Soil Health and Strawberry Nutritive ValueSoils and strawberries from 13 matched pairs of organically and conventionally managed fields were assessed over two years. Available plant nutrients were generally similar under organic and conventional management except that organically managed soils contained more available Zn and B. Soil C, N, and biological parameters were much greater under organic management. Organically produced strawberries matched by variety were smaller and had greater dry matter content than conventionally produced... L. Carpenter-boggs, J. Reganold, J. Reeve, P. Andrews |
29. 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 |
30. 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 |
31. 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 |
32. 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 |
33. Nitrogen and Phosphorus: Mechanisms of Loss from the Soil System and Effects to Slow Those Losses and Increase Plant AvailabilityNutrient management issues associated with production agriculture are becoming more of a concern and a focal point of discussion. Management considerations are no longer focused on just meeting yield goals or improved crop performance, but now include questions on how their use on agriculture lands impacts surface water, watersheds, soil quality, long-term health benefits and economic viability for the producer. ... T. Tindall, G. Mooso |
34. 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 |
35. Phytosiderophore Exudation from the Roots of Iron Stressed Kentucky BluegrassSome Kentucky bluegrass (Poa pratensis L., KBG) cultivars are susceptible to iron (Fe) deficiency chlorosis when grown on calcareous soils and are routinely treated with Fe fertilizers. Aesthetics could be improved and this costly practice could potentially be eliminated with the use of cultivars resistant to Fe deficiency. Grasses are known to release phytosiderophore into the rhizosphere to dissolve Fe for plant use, and this characteristic has been used to screen for resistant... B. Hopkins, E. Buxton, V. Jolley, R. Christensen |
36. 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 |
37. Comparison of Induced Sludge Bed (Blanket) Anaerobic Reactor to Vertical Plug Flow Technology for Animal Manure Digestion1The purpose of this study was to compare Induced Sludge Bed Anaerobic Reactor (IBR) (Hansen, Hansen, 2005) animal manure digestion technology to Vertical Plug Flow (VPF). In 2008 an IBR system at Sunderland Dairy Farm in Chester, Utah was repaired and retrofitted by Utah State University (USU), Extension, Utah Science, Technology and Research Initiative (USTAR), and Sunderland Dairy Farm. This was the first time research has compared IBR and VPF digester performance at a single site in a side-by-side... J. Gale, P. Zemke, B. Wood, S. Sunderland, S. Weeks |
38. 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 |
39. An Evaluation of the Effects of Diversified Cropping Systems on Soil Organic Matter, Nutrient Dynamics, Yield and Economics of Dry Land Winter Wheat and Irrigated Sugar Beet in WyomingThe overall objective of this study is to evaluate the effects of different cropping systems and irrigation methods used by Wyoming farmers on soil chemical, biological and physical properties, yield, economic returns and long term ecological sustainability of dryland and irrigated crop production. The Project, which is being carried out on dryland winter wheat systems in the Albin and Slater areas and on irrigated sugar beet systems in the Big Horn basin near Powell, will go... J. Norton, E. Mukhwana |
40. 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 |
41. 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 |
42. 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 |
43. Determining Plant Available Nitrogen from Manure and Compost Topdressed on an Irrigated PastureComposting manure is a practice that is gaining acceptance as an environmentally sound manure management practice at large animal production operations. Composting produces a value-added product that enhances the fertility and physical properties of soil. During the composting process, nitrogen and phosphorus in the original feedstocks are converted through microbial activity into predominantly stable organic compounds, lessening the risk of loss of these nutrients into the environment. Compost... J. G. davis, T. Bauder, K. Corwin doesken, A. Elliott |
44. Nitrogen Cycling and Partitioning Under Alternative Organic Orchard Floor Management StrategiesOrganic orchard systems are a significant and growing component of Washington State agriculture, yet sustainable methods of nitrogen (N) fertility and weed management remain a challenge. Nutrient supply is dependent on decomposition and mineralization of organic matter, yet intensive cultivation commonly used to control weeds can disrupt biological processes and cause loss of organic matter. To address the often-competing goals of organic fertility and weed control, a number of alternative orchard... L. Carpenter-boggs, D. Granatstein, J. Reganold, L. Hoagland, M. Mazzola, F. Peryea, J. Smith |
45. 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 |
46. No-till Grain Production in Wyoming: Status and PotentialIn dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, or continuously, without fallow, but water and nutrient needs are much more closely balanced with... J. Norton |
47. 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 |
48. Is Protein Enough for Assessing Wheat Flour Quality?The quality of wheat products such as bread, bagels, noodles or pizza that consumers purchase is based on the flour quality used in production. Flours with different characteristcs are needed to produce different products and flour quality is important to produce a quality end product. However, at the initial stage of flour production, wheat is sold on a grain protein premium basis by farmers to elevators and eventually millers. In many years, higher protein (> 15% protein) wheat can bring... C. Reese, D. Clay, D. Beck, R. Englund |
49. 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 |
50. 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 |
51. Recent Advances in P Fertilizer Technologies—polymer Coatings and Avail TechnologyPhosphorus fertilizers are an essential part of plant production and have been recognized as such for well over 100 years. Phosphorus utilization by crops is related to both soil availability as well as an individual plants metabolic process that allows P to be taken up by a plant as well as utilized for a wide variety of developmental processes. ... T. Tindall |
52. 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 |
53. 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 |
54. 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 |
55. CropManage Decision Support Tool for Improving Irrigation and Nutrient Efficiency of Cool Season Vegetables in California: a Decade of Field Demonstrations and OutreachVegetable growers on the central coast of California are under regulatory pressure to reduce nitrate loading to ground and surface water supplies. California is also implementing the Sustainable Groundwater Management Act (SGMA) which may limit agricultural pumping in regions such as the central coast where the aquifer has been over-extracted for irrigation of crops. Growers could potentially use less N fertilizer, address water quality concerns, and conserve water by improving water... M. Cahn, R. Smith, L. Johnson, F. Melton |
56. Flushed Liquid Dairy Manure Solid Particle and Nutrient DistributionsLarge dairies often use liquid manure handling systems because of their ease of mechanization and low labor requirements. Some of Idaho Magic Valley dairies use flushing systems that result in large amounts of liquid dairy manure that are applied via irrigation systems to adjacent cropland during the growing season. Solids and nutrients found in liquid dairy manure pose challenges to manure handling processes and cause environmental concerns. Separating solids and nutrients from liquid dairy manure... L. Chen, K. Kruger |