Our Current Research Projects:
Fertilizer is a component of sustainable crop production systems, and the fertilizer industry recognizes the need to efficiently utilize these nutrients. The 4R philosophy is an innovative and science-based approach that offers enhanced environmental protection, increased production, increased farmer profitability, and improved sustainability. The concept is to use the right fertilizer source, at the right rate, at the right time, with the right placement. Implications of the 4R nutrient stewardship system will spread far and wide through agriculture and society as a whole. For fertilizer use to be sustainable, it must support cropping systems that provide economic, social, and environmental benefits. Two goals within the initiative include establishing 4Rs as a recognizable strategy for economic, social, and environmental sustainability and expanding the adoption of 4R nutrient stewardship as well as the awareness of these efforts to federal and state program officials.
Dr. Fred Below and Ross Bender, University of Illinois
While irrigated crop acreage in Illinois is limited in scope (435,000 acres or approximately 2% of total crop acres as of a 2005 survey), it has experienced a 48-fold increase compared to the first estimate of irrigated Illinois crop production in 1950. Although irrigation is often a necessity in areas with sandy soil textures (e.g., Mason County), use of irrigation in other areas may become attractive to crop producers as a strategy to reduce annual yield variability associated with insufficient precipitation or for high-value crops such as seed corn production. As such, irrigated crop acres in Illinois are anticipated to expand by an additional 40% by the year 2025. Sub-surface drip irrigation (SDI) is not a new technology and has been used for many years in the production of high-value vegetable and fruit crops such as tomato. More recently, it has been adopted for commodity rows crops such as corn and cotton as an alternative to center-pivot or flood irrigation. The objectives of this project is to; 1) Investigate drip irrigation as a possible strategy to improve the efficiency of nutrient uptake and use when liquid nutrients are applied at key growth stages compared to a conventional granular broadcast and side-dress fertility program and 2) Understand how drip irrigation and fertigation can be optimized in a high yield agronomic system with complementary agronomic management practices including hybrid and variety selection and crop protection.
Dr. Ignacio Ciampitti, Kansas State University
More research information is needed as related to the interactions among crop production practices and nutrient fertilization for optimizing inputs and maximizing sorghum yield at very diverse environments. In addition, previous information related to nutrient concentration in different plant tissue for sorghum in Kansas (and the region) needs to be updated (Vanderlip, 1972). Information for modern hybrids is scarce, and the effect of combined management practices on the nutrient partitioning process is relatively unknown. Balanced nutrient application for maximizing yields under crop management practices should be further studied for grain sorghum under diverse environments around the state. The overall research goal is to identify the effect of nutrient fertilizer applications and their interactions with diverse management factors that contribute to high yields, and to quantify how those practices impact yield formation and nutrient uptake processes. A secondary objective will be to quantify the yield potential for each particular environment evaluated, and to determine the contribution of the balanced nutrient fertilization and each specific crop management factor in reducing sorghum yield gaps (herein understood as the difference between the potential yield and the current farmer practice).
Dr. David Bryla, USDA-ARS Corvallis, OR
Consumption of blueberries has increased rapidly in recent years, primarily due to promotion of their health benefits and to greater availability of the fruit year round. Recently, we determined that drip fertigation with various fluid NH4-N sources, including ammonium sulfate, urea, and urea sulfuric acid, produced more growth and greater yield than conventional granular fertilizers in highbush blueberry. Potassium is usually applied to blueberry as potassium sulfate. Potassium chloride (muriate of potash) is also sometimes used but is not recommended because blueberry is very sensitive to chloride. Other potential sources include mono potassium phosphate, which is largely a source of P, and potassium thiosulfate (KTS). The latter may be particularly useful in high pH soils such as those in California and eastern Oregon and Washington because the product is acidifying (thiosulfate is oxidized by Thiobacillus bacteria to produce sulfuric acid). Potassium nitrate is also a popular K fertilizer available for fertigation, but it is expensive and a poor N source (i.e., NO3-N) for blueberry. The goal of proposed project is to develop guidelines for K fertigation in blueberry using KTS. The results will help growers improve production in the crop and enhance fruit quality for consumers.
Dr. Gaylon Morgan, Texas A&M
Previous research in 2012 and 2013 trials at six field sites with a previous history of K deficiencies were conducted in the Blacklands of Texas and the Upper Gulf Coast region. Lint yield were significantly increased with increasing K rates in fields with 150 ppm or less. See Wharton and Williamson county trial results below. Liquid K injected had a greater positive effect on lint yield compared to granular K incorporated. Additionally, the injected K increased yields even at the higher application rates and at the locations exceeding the current soil threshold level of 125 ppm of K. The injected K improved length, strength and uniformity at the Williamson site. As a result of the substantial yield response in Texas in 2012 and 2013, there is a strong interest in evaluating liquid injected applications of K across the Cotton Belt at a minimum of eight locations.
Dr. Ignacio A. Ciampitti, Kansas State University
The overall research goal is to study the contribution of nitrogen on high-yielding soybean systems under diverse germplasm and production practices. Closing yield gaps (actual on-farm yield vs. genetic yield potential) in a long-term perspective will require an improvement in the utilization of the available resources, which must be attained via implementation of better management decisions. Impacts of these diverse agricultural scenarios or technology packages on biomass and nutrient accumulation for the season-long and yield formation will be quantified with the goal of more properly understanding how these systems can sustainably reduce yield gaps through improving the efficiency in capturing and utilizing natural resources and inputs (e.g., sunlight, water, and nutrients) for increasing productivity at the cropping-system-scale.
Dr. Robert Miller, Colorado State University
Recent research from a potassium fertilizer project conducted by Midwest Independent Soil Samplers across 61 locations across Nebraska, Iowa, Illinois, Wisconsin and Indiana 2011-2013, indicates a 43% response to K fertilizer K on soils with STK levels 85 – 600 ppm, with an average response of 9 bu/ac (Miller, 2012). Results were consistent over locations and years. Generally, soils with STK stratification by depth showed the greatest yield response. Increasingly corn growers have shown interest in side dress applications of N fertilizers, which improve efficiency and minimize losses. Vegetative growth uptake of N and K are generally paired in a ratio of 1:0.8 (Karlen et al, 1987), thus the application of both of N and K during early vegetative growth stages is likely to improve corn yield than N alone. With increasing yield and greater interest in season nutrient applications, the objective of this project is to evaluate corn response to side dress applications of N and K across a range of corn populations, and to assess types of K application.
Drs. Dan Kaiser and Jeffery Vetsch, University of Minnesota
Research in Minnesota has clearly identified the need for sulfur for corn production. Placement comparisons (band vs. broadcast) of sulfur on medium and fine textured soils have not been researched for many years. Many farmers want to apply sulfur with their broadcast P and K in the fall but are concerned with loss of sulfate sulfur prior to corn planting. Liquid fertilizer sources containing sulfur such as ATS provide a viable alternative for band application with the planter or for a broadcast pre-emerge application with or without herbicides. Concentrating sulfur near the roots where it is needed the most early in the growing season may be a more efficient use of fertilizer but we do not have any current research comparing band and broadcast application of sulfur. If growers wish to apply ATS over the top as a pre-emergence application we need more information whether this type of application is as effective as an application of AMS at or prior to planting. We currently do not suggest changing S application rate based on the use of ATS versus AMS. The relative effectiveness of ATS placement is needed in order to fine tune new guidelines for sulfur application to corn. The objectives of this project are to determine if a surface band application of S as ATS is more efficient than broadcast application of ATS or AMS and to determine if pre-emerge broadcast application of ATS is as an effective source of applying S compared to AMS broadcast at or before planting in continuous corn.
Dr. Ricardo Melgar, INTA, Pergamino, Argentina
Recent soil nutrient surveys in the main grain producing region of Argentina indicate a generalized and growing deficiency of zinc and boron . Although awareness of farmers is still low, companies start to offer a variety of possible sources for coping with the situation, mainly foliar formulations and some imported complexes to apply to soils at planting. Usual ways to provide micronutrients to annual crops can be classified as to soil application, foliar sprays and seed coatings. The objectives of this work is to determine the best formulation and placement for providing micronutrients no-till Argentine crops. To compare two granular formulations with a fluid source of micronutrients applied to soil at sowing for high grain yields of corn and soybean.
Dr. Ray Asebedo, Kansas State University
Nitrogen management is becoming one of the more complex aspects of modern corn production. Changes in plant genetics, earlier planting dates, larger farm size which compresses time available for field work per acre, equipment innovations, increasing fuel and N costs, as well as concerns with potential environmental contamination all contribute to this increased complexity. Balancing time and financial resources in an effort to maximize yield and profitability, while still being a good environmental steward has become difficult for producers. Recent advances in crop and soil sensor technology may provide a better estimate of the interaction of soil and crop yield determining factors. The utilization of pre-plant on-the-go soil sensor technology for quantifying soil characteristics, coupled with in-season crop sensor technology at specific yield determining growth stages may provide in-depth agronomic information for improving the efficiency of N management in corn. The objectives of this work is to; Measure the impact of N rate and time of application (N management system) on yield, profitability and nitrogen use efficiency in high yielding corn production, to evaluate the efficacy of prototype agronomic algorithms that utilize soil and crop sensor technology to determine the optimum N rate with variable rate applications (VRA) and to compare the costs and profitability of sensor-based VRA N management, spad meter N management, and traditional pre-plant N management.
Dr. William Hunter Frame, Virginia Tech
Environmental regulations, such as the Clean Air Act, have reduced the S emissions from coal burning power plants, thus reducing atmospheric S deposition on cropland. Historically, S deposition contributed to acidification of surface waters, nutrient enrichment of surface waters, decline of sensitive forests, and impacts on ecosystem biodiversidity (E.P.A, 1999). That same deposition provided a free source of N and S in crop fields and mitigated S deficiencies in areas where natural S fertility is low. As a result of reduced atmospheric S deposition, S responses in coarse textured soils with low organic matter have increased across the southeast and mid-south U.S. growing regions. The objectives of this project is to evaluate granular and fluid N sources with varying S application rates on cotton in the upper southeast coastal plain and to determine the effect of high N:S ratios in side-dress fluid N sources at varying N application rates on NDVI, petiole and leaf N:S ratios, and lint yield.
Dr. Dorivar Ruiz Diaz, Kansas State University
Higher yield potential and stay-green characteristics of modern corn hybrids require improvements to current fertilizer N management practices. New corn genetics may benefit from late N applications in combination with management practices such as late fungicide applications. The combination of late N and fungicide may benefit corn hybrids that may have the capacity to stay green longer and until much later in the grain filling period contributing to significant yield increase. The effect of late fungicide applications to help maintain leaf health and its effect on N use has not been evaluated. High clearance equipment are becoming widely available and producers and retailers can utilize this equipment not only for spraying chemicals; but also for the application of fluid fertilizers at late-vegetative stages. The overall objective of this study is to assess the value of split N application with late vegetative application time with emphasis on yield and NUE. Specific objectives include (1) evaluate nitrogen use efficiency (NUE) with split N applications including late-vegetative N application, (2) evaluate the benefit of fungicide applications on yield and NUE with late N applications and (3) assess the value of foliar N the application using N sources with urea ormaldehyde/triazone during late vegetative stages (VT-R1).
Dr. Miguel Cabrera, University of Georgia
Surface application of UAN solution to grasslands results in losses of ammonia (NH3) that vary depending on environmental variables such as temperature, relative humidity, rainfall, and soil water content. Our previous research on Southern Piedmont pastures in Georgia has shown NH3 losses from UAN ranging from 6 to 33% of the applied N (Vaio et al., 2008). These emissions of NH3 to the atmosphere decrease the efficiency of the applied N although the lost NH3 is eventually deposited back to soil or water through wet and dry deposition. Ammonia deposition in riparian and forest areas contributes to soil acidification through nitrification and acts as an indirect source of nitrous oxide (N2O), a greenhouse gas (Mosier et al., 1998). In surface waters, deposition of NH3 may lead to eutrophication in streams, rivers, and lakes (Lewis et al., 2011). Thus, identifying practices that reduce NH3 losses from grasslands is important to improve UAN efficiency and to decrease potential environmental problems. The objectives of this work are to evaluate the effect of method of UAN application (broadcast or dribble) to tall fescue/bermudagrass grasslands on: forage yield and apparent N recovery, rate of urea hydrolysis, NH3 volatilization and surface runoff losses of inorganic N and urea.