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Authors
Ahola, J
Anderson, A.J
Arthur, D.K
Bjorneberg, D
Bjorneberg, D.L
Bremer, E
Britt, D.W
Bronson, K.F
Brown, P.H
Brummer, J
Buck, R.L
Bush, T.V
Carpenter-Boggs, L
Carter, P
Cartwright, A
Cole, D.L
Collins, D
Crowe, V
D'Agati, K
Dari, B
Davenport, J.R
Davis, A.G
DeVetter, L.W
Deakin, J.W
Donaldson, A
Dungan, R
Evans, C
Fahning, S.R
Fernandez, F.G
Fransen, S
Geary, B.T
Gent, D
Ghimire, R
Gonzalez-Mateu, M
Greer, K
Griffin, D
Griffin-LaHue, D
Haas, S
Harrison, J
Heidenreich, D.T
Helseth, C
Hoheisel, G.A
Hopkins, B
Hopkins, B.G
Hortin, J
Horwath, W
Housman, M
Huggins, D
Huggins, D.R
Ippolito, J
Jacobson, A.R
Jayawardena, D.M
Jeliazkova, E
Jones, C
Khalsa, S.S
Kleinman, P.J
Kobza, S.J
Lambert, A.M
Llewellyn, D
Loomis, G
Lyons, S.E
Marshall, J
McGrath, J.M
McIlquham, M
McLean, J.E
Mcilquham, M
Michel, L
Miller, P
Miller, R
Moore, A
Moore, E
Nichol, C
Norberg, S
Norton, J
Norton, U
Olsen, D
Osmond, D.L
Peachey, R.E
Pearce, A.W
Potter, M
Reganold, J
Reganold, J.P
Rhoades, R
Rieser, C
Rodgers, H
Rogers, C
Salehin, S
Sarpong, K
Sarpong, K.A
Schroeder, K
Seely, C.J
Shafian, S
Shawver, C
Shiwakoti, S
Slaton, N.A
Spackman, J.A
Spargo, J.T
Sparks, D
Spring, J
Stacey, N
Stapley, S
Stapley, S.H
Steenwerth, K
Sullivan, D
Tallman, S
Tarkalson, D
Tarkalson, D.D
Thurgood, G
Van Vleet, S
Verhoeven, B
Walsh, O.S
Weisshaar, E.M
Whitefield, L
Wiebe, J
Wieme, R
Wilson, T
Yi, Q
Zabinski, C
Zapata, D
Zhu-Barker, X
van Diepen, L
Topics
Soil Fertility and Soil Health Testing
Manure and Compost Management
Recycled and Repurposed Nutrient Sources
Liming and Soil Acidity
Fertilizer Evaluations
Crop Nutrient Management
Nutrient Management of Agronomic Crops
Nutrient Management of Horticultural Crops
Organic Amendments, Cover Crops, and Soil Health
Type
Oral
Poster
Year
2021
Home » Year » Results

Year

Filter results44 paper(s) found.

1. Evaluating Nutrient Uptake and Partitioning for Hybrid Carrot Seed Production in Central Oregon

Hybrid carrot seed production is prominent in Central Oregon, however plant nutrient uptake dynamics in this crop are not well understood. The aim of this research was to evaluate nutrient uptake and partitioning during the production cycle of a modern Nantes-type hybrid carrot. Trials were conducted in two commercial carrot seed production fields planted to ‘Nantes 969’. Below- and above-ground plant biomass was destructively sampled and separated into roots, tops, and umbels thr... E. Jeliazkova, A. Moore, J. Spring, T. Wilson

2. 15Nitrogen Uptake and Use Efficiency in Corn in Response to Fertilizer Rate and Timing

Urea fertilizer applications at planting are becoming increasingly common for U.S. upper Midwest corn (Zea mays L.) production but wet spring conditions may result in significant nitrogen (N) fertilizer loss. Split-applications may avoid wet conditions and improve fertilizer uptake and use efficiency. Six field studies were performed to determine the effect of urea fertilizer rate and application timing on fertilizer-derived N (FDN) and soil-derived N (SDN) plant uptake over two cons... F. Fernandez, J. Spackman

3. Assessing Nutrient Uptake and Accumulation in Oregon Hop Production

Commercial 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, m... A. Moore, D. Gent, B. Verhoeven

4. Comparative Analysis of Soil Tests for Soil Health and Nutrient Management

Options for soil tests to address soil health and nutrient management objectives have diversified. We compare different soil test methods to evaluate their similarities for providing recommendations. Traditional soil tests, ion exchange membranes and analyses using the Haney Soil Health Nutrient Tool and Soil Health Index were compared for soil sampled from long-term cropping system trials near Ritzville Washington and from the R.J. Cook Agronomy Farm near Pullman WA. Despite strong... D. Huggins, C. Rieser, J. Reganold

5. Compost Application in California Tomato Cropping Systems

With the implementation of California Assembly Bill (AB) 341 the availability of composts such as green waste (GW) and co-composted green waste and food waste (FW) as a soil amendment is increasing. The use of those organic amendments in agricultural production systems has been recommended as an effective strategy to make full use of organic waste and improve soil health. However, little information is available to tomato growers to reassess N inputs from using GW and FW. This study was condu... Q. Yi, W. Horwath, S. Haas, X. Zhu-barker

6. Cover Crop Suitability for High Altitude Specialty Crop Organic Food Production

There 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, a... E. Moore, U. Norton

7. Dairy Manure and Fertilizer Effects on Microbial Activity of an Idaho Soil

Dairy manure applications that have occurred in the past can have long-term lingering effects on crop production. Understanding the cause is important for current and future management practices. This study was conducted to assess selected microbial activity among past manure application rates.  In a past study (2014-2016) in Kimberly Idaho, historic manure applications have been shown to have significant positive and negative effects on sugar beet production. The manure treatment histor... D.D. Tarkalson, R. Dungan, D. Bjorneberg

8. Denitrifying Woodchip Bioreactor Performance in the Pacific Northwest

Runoff and tile drainage from agricultural activity is known to be a significant contributor of nitrogen pollution to surface waters.  Denitrifying woodchip bioreactors, also known as Permeable Reactive Barriers (PBR) have been studied as a possible edge-of-field technology for reducing nitrogen concentrations in agricultural runoff.  These units have been studied mostly in the US Midwest and mostly for irrigated crop systems.  Little work has been done in alternative climate r... E.M. Weisshaar

9. Developing a Soil Health Assessment Framework for Specialty Crop Systems and Soils of Washington State

To 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 ... K.A. Sarpong, M. Mcilquham, L. Michel, D. Griffin

10. Does Post-harvest Nitrogen Application Affect Blueberry Yield or Cold Hardiness?

In central Washington, nitrogen (N) management in blueberries typically consists of all N being applied prior to harvest.  For early cultivars, such as Duke, this means all fertilizer is applied before the end of June, leaving a long period of growth with no supplemental N.  To evaluate the potential for splitting N fertilizer applications into pre- and post-harvest timings, we conducted an experiment in a randomized complete block design with four replicates on a commercial ‘... J.R. Davenport, G.A. Hoheisel, L.W. Devetter

11. Dryland Organic Winter Wheat Improvement by the Inclusion of Composted Cattle Manure and Cover Crops

Organic agriculture in semi-arid environments can face several challenges in order to produce a successful crop.  These include nitrogen and phosphorus deficiencies, moisture limitations, and high weed competition.  Organic winter wheat (Triticum aestivum, L.)-fallow systems can be amended with composted cattle manure and with green manure from cover crops grown in the fallow phase to help increase wheat yields and quality.  Cattle manure can improve soil health with t... C. Helseth, U. Norton

12. Effects of Lime and Micronutrient Amendments for Acidic Soils of the Inland Pacific Northwest

The 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 als... R. Wieme, L. Carpenter-boggs, P. Carter, S. Van vleet

13. Effects of Semiarid Wheat Agriculture on Soil Microbial Properties: A Review

Agricultural management decisions on factors such as tillage, fertilization, and cropping system determine the fate of much of the world’s soils, and ... J. Norton, H. Rodgers, L. Van diepen

14. Enhanced Efficiency Nitrogen Fertilizer: Coated Urea

Nitrogen is the most common fertilizer applied to crops, as it is typically the limiting nutrient in plants. However, about half of the nitrogen added to soil as fertilizer is either emitted to the atmosphere as ammonia, nitrous oxide or other gaseous forms, or finds its way into surface or ground waters as nitrate (Kibblewhite, 2007). The inefficient use of fertilizers depletes natural resources, and increases atmospheric emissions and environmental pollutants. With the use of enhanced effic... B. Geary, S.R. Fahning, B.G. Hopkins

15. Enhanced Efficiency Phosphorus Fertilizers

Phosphorus (P) is essential for plants. However, first-year phosphorus fertilizer uptake by plants is low, resulting in economic and environmental impacts. Developments with P Enhanced Efficiency Fertilizer (EEF) sources show improved uptake efficiency and increased yield and/or crop quality, while reducing environmental risk. Research with EEFs (including organic acids, maleic itaconic copolymer, and struvite) all show these improvements, especially when: 1) soil test P concentrations are lo... B. Hopkins, S.J. Kobza, C. Seely

16. Estimating Nitrogen Credits from Organic Matter Sources in Orchards

Orchard 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 credi... S.S. Khalsa, P.H. Brown

17. Evaluating Cover Crops for Nitrogen Management in a Walnut Orchard

Cover 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 w... D. Zapata, X. Zhu-barker, K. Steenwerth, W. Horwath

18. Evaluation of Lime Requirement Estimation Methods for Oregon Agricultural Soils

Soil 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 a... C. Evans, A. Moore, D. Sullivan

19. Factors Influencing Efficacy of Elemental Sulphur Fertilizers

Elemental sulfur is a byproduct of fossil fuel production and produced in large quantities in both the US and Canada.  Fertilizers containing elemental S have a high S content and low manufacturing cost, but may not reliably meet crop requirements for S in the year of application due to the time required for elemental S to be oxidized.  The main factors influencing the oxidation rate of elemental S are particle size, particle dispersion and environmental conditions.  ... E. Bremer

20. Impact of Soil Health Practices in an Irrigated Agroecosystem

Regional 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 (diversificati... T. Vance, V. Crowe, J. Norton

21. 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, ... D.D. Tarkalson, D.L. Bjorneberg

22. Is Cover Crop Species Mixture and Diversity More Important at Building Soil Health than Shoot Biomass in a Semi-arid Region?

Cover crop mixtures (CCMs) as partial fallow replacements have the potential to increase soil health, yet long-term studies on CCMs, especially in semi-arid environments are relatively rare. An eight-year study at two locations in semi-arid Montana sought to evaluate the effect of functional group (N fixer, tap roots, fibrous roots, brassicacae) and species richness (2, 6, and 8 species in a mix) on a range of biological, physical and chemical soil parameters. Although several soil healt... P. Miller, C. Jones, C. Zabinski, K. D'agati, M. Housman, S. Tallman

23. 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 experimen... 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

24. 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 re... B. Verhoeven, A. Moore, D. Sullivan, M. Gonzalez-mateu

25. Long-term Soil Profile Acidification: Obvious and Hidden Dangers

Soil 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

26. New Hydroponic System for Testing Mineral Nutrient Deficiencies: Quinoa

Correlating plant tissue nutrient concentrations with visual symptoms is valuable in combating mineral nutrient deficiencies and toxicities. Major crops tend to have adequate information regarding nutrient concentrations and visual symptoms of deficiencies, but this is often lacking for minor crops, including quinoa (Chenopodium quinoa L.) Because nutrient concentrations can be easily controlled, hydroponics effectively demonstrate isolated specific nutrient related symptoms. Ho... D.L. Cole, D.T. Heidenreich, S.H. Stapley, A.M. Lambert, R.L. Buck, B.G. Hopkins

27. Nitrogen and Water Management for Optimized Sugar Beet Yield and Sugar Content

Sugar beet (SB) production is based on maximizing: root yield, and sucrose content, and sucrose recovery efficiency. Efficient nitrogen (N) and water management are key for successful SB production. Nitrogen deficits in the soil can reduce root and sugar yield. Overapplication of N can reduce sucrose content and increase nitrate impurities which lowers sucrose recovery. Application of N in excess of SB crop need leads to vigorous canopy growth, while compromising root development and sugar pr... O.S. Walsh, S. Shafian, D. Jayawardena

28. 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

29. Refining Nitrogen Management for Organic Broccoli Production

Specialty 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 s... D. Sullivan, R.E. Peachey, A. Donaldson

30. Repurposing Zinc from Mining Tire Waste to a Fertilizer Resource

Zinc (Zn) deficiency is common on high pH soils when growing field crops like Corn, Barley and Wheat.  Not only are crop yields and quality limited by low Zn, but more importantly the dilution of Zn in food stuffs and, thereby, Zn deficiency in the human diet has become a major concern as recognized by the World Health Organization.  At the same time, there is a Global problem in proper repurposing/disposal of used tires that contain between 1-3% ZnO.  In fact, in Chile, t... K. Greer, J. Wiebe, E. Bremer

31. Residue Decomposition of Surface and Incorporated Barley, Corn, and Wheat at Varying Fertilizer-N Rates

Cereal crops are commonly grown in southern Idaho and most parts of the western United States. These cereal crops are routinely harvested for their grain with the remaining plant material (chaff, stems, leaves, etc.) left in the field to decompose prior to planting of following spring crops. Understanding the effects of post-harvest residue management on barley (Hordeum vulgare L.), corn (Zea mays L.), and wheat (Tritcum aestivum L.) residue is important for optimiz... C. Rogers, G. Thurgood, B. Dari, J. Marshall, O.S. Walsh, K. Schroeder, G. Loomis

32. Reuse and Reclamation of Phosphogypsum

Phosphogypsum (PG) is a byproduct of phosphate fertilizer production.  It is produced when phosphate rock is treated with sulphuric acid during the manufacture of phosphoric acid, and is composed primarily of  gypsum (CaSO4.2H2O).  It is estimated that over 3 billion tonnes of PG have been accumulated in stacks worldwide and over 150 million tonnes are produced annually.  In North America, PG is stockpiled in stacks that can cover hund... C. Nichol

33. Sensor-Based Nitrogen for Spring Wheat

Management of nitrogen (N) fertilizer during wheat production needs to vary depending on the variety as they have different N requirements. Though many growers prefer planting older varieties that they are already familiar with, increasing the knowledge on N requirements of newly released varieties will help to improve the adoption of these varieties by growers. Therefore, the main goals of this study were to assess grain yield, grain N uptake and N use efficiency (NUE) of new and traditional... D.M. Jaywardena, O.S. Walsh

34. Soil Health and Ecological Resilience on the Palouse

Healthy soil is critical for global food security and other essential ecosystem services but is threatened by processes of soil degradation, with at least 33% of global croplands estimated to be moderately or highly degraded. Current soil health assessments provide insight into soil functional performance but often lack diagnostic criteria that assess management effects on soil function over time. We integrate soil health assessments with ecological resilience theory to better understand mana... A.G. Davis, D.R. Huggins, J.P. Reganold

35. Soil Health Changes Following Transition from an Annual Cropping to Perennial Management-Intensive Grazing Agroecosystem

Management-intensive Grazing (MiG) on irrigated, perennial pastures has steadily increased in the western US due to pressure for reducing public lands grazing, overall declining land available for pasture, and decreasing commodity prices. However, there are still many unknowns regarding MiG and its environmental impact, especially with regards to soil health. Over a two-year period, we studied changes in soil health under a full-scale, 82 ha pivot-irrigated perennial pasture system grazed wit... J. Ippolito, C. Shawver, J. Brummer, J. Ahola, R. Rhoades

36. Soil Organic Carbon and Nitrogen Dynamics Under Dryland Sorghum in New Mexico

Sorghum [Sorghum bicolor (L.) Moench] serves as a low-cost alternative to corn (Zea mays L.) in semi-arid regions of the world because of its high N and water use efficiencies. However, there has been a concern regarding N loss to the atmosphere as nitrous oxide (N2O) from semi-arid drylands. This study investigated various soil C and N components, including CO2 and N2O emissions, and crop yield with a dairy compost (13.5 Mg ha-1) ... R. Ghimire, S. Salehin

37. Soil Test Interpretation: Saturated Paste, EC, SAR and CEC

Soils of neutral to alkaline pH of the Western United States often contain elevated levels of soluble salts and / or higher concentrations of sodium.  Elevated concentrations of soluble salts limit crop growth and sodium may impact water management.  Competent agricultural management of these soils is dependent on laboratory analysis of: soil soluble salts and there composition and the irrigation water soluble salt constituents.  Soil analysis based on the satura... R. Miller

38. Stacking and Intersecting Nutrient 4Rs and Using In-Season Canopy Health and Petiole Nitrate Analysis on Russet Burbank Potatoes

The 4Rs of nutrient management is a global outreach with an aim to improve the sustainability of major cropping systems and the environment. The objective for this project is to evaluate individual and stacked 4R management practices and how they intersect in Russet Burbank potato at a field near Grace, Idaho in 2020. Nitrogen (N) fertilizer treatments included all combinations of two sources [urea vs polymer coated urea (PCU)], two rates (207 vs. 247 kg ha-1), and two timing/place... S. Stapley, B. Hopkins

39. Static Range Nitrogen Management in Northwest U.S. Sugarbeet Production

Nitrogen (N) management is important in sugarbeet production. This paper presents data to support a shift from a yield-based N management approach to a static range N management approach in the Northwest U.S. Production data and research show that yield-based N management can result in over application of N. Past research has been critical to improving and understanding sugarbeet N nutrition. However continued research is needed so cumulative data can be evaluated to improve management practi... D. Bjorneberg, D. Tarkalson, D. Olsen

40. Sugar Beet Lime Effects on High pH Soils and Crops in Northwest U.S.

A viable solution to dispose of sugar beet precipitation calcium carbonate (PCC) is needed due to the unsustainable issues associated with storage. Sugar beet PCC is a lime material produced as a waste product from extracting sugar from sugar beet. The three main sugar beet processing factories in the Amalgamated Sugar Company growing area in Idaho and Oregon have stockpiled approximately 11.3 million Mg of PCC.  Each year these three factories produce a total of 350,000 Mg annually. &nb... D.D. Tarkalson

41. The Elasticity of Biochar Across the Farm: Nutrient Capture, Compost Feedstock, and Soil Amendment

When biomass is thermochemically altered through pyrolysis, what results is biochar, a solid, porous material that is high in carbon (C) (e.g. 80%).  Owing to its unique physicochemical properties, biochar has been evaluated as a soil amendment, a compost feedstock, a means to mitigate nutrient loss and a way to sequester carbon.  Biochar is an appealing material as a farm management tool because its potential use is varied.  As part of a Western SARE grant, soil scientists at ... N. Stacey, D. Collins

42. The Fertilizer Recommendation Support Tool (FRST) Initiative: National Survey on Soil Fertility Recommendations and Correlation/Calibration Database

Soil 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 l... S.E. Lyons, J.T. Spargo, D.L. Osmond, A.W. Pearce, N.A. Slaton, D.K. Arthur, P.J. Kleinman, J.M. Mcgrath

43. Twenty Years of Cotton Nitrogen Management and Cycling Trials in the Southwest: What Have We Learned?

Over 20 site-years of nitrogen fertilizer management and cycling trials have been conducted in Lubbock Texas and Maricopa Arizona from 1998 to 2019.  Furrow, overhead sprinkler (OSI), subsurface drip irrigation (SDI) were used.  Soil profile nitrate (0-36 inches in Texas and 0-72 inches in Arizona) was sampled and tested for in all trials.  Nitrogen-15 labeled fertilizer was used for two years in Texas and for two years in Arizona.  Canopy reflectance was measured in every... K.F. Bronson

44. Vineyard Soil Health: What Soil Properties are Most Important?

Washington is the second leading producer of wine grapes (Vitis vinifera) in the US, with over 60,000 acres in vineyards. With such a substantial acreage, it is crucial to know how management practices may affect soil and vine health in wine grape systems. Soil health indicators and threshold values have been extensively studied in commodity crops in the Midwest and the northeastern US, but there is much less information available for specialty crops in the Pacific Northwest. &... M. Mcilquham, D. Griffin-lahue, K. Sarpong, L. Michel