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1. US Midwest Dairy Manure Nutrient Observations 2012-2022Dairy manure is a source of organic nutrients with variable manure characteristics. This analysis drew 2012-2022 data from ManureDB, the manure and organic amendment database developed by the University of Minnesota. Thousands of solid dairy and liquid dairy manure samples across 2012-2022 were evaluated for book value comparisons, temporal trends, and regional differences for total N, NH4-N, P2O5, and K2O analytes. The only significant trend detect... N. Bohl Bormann, M. Wilson, E.L. Cortus, K.A. Silverstein, K.A. Janni, L. Gunderson |
2. A Look at West, Texas(Blank Page for Notes) ... |
3. Adapt-N: A Computational Tool for Precise N Management in CornCurrent approaches to estimation of optimum N fertilizer rates are based on mass balances, average expected economic return based on field experiments, soil N tests, an d crop leaf or canopy sensing. However, denitrification and leaching losses of nitrogen may occur from dynamic and complex interactions among weather, soil hydrology, crop water and N uptake, and management practices , and result in high variability in annual crop N needs in maize ( Zea mays L.) production. W eather impacts the ... |
4. Adaptive Nitrogen Management(Blank Page for Notes) ... |
5. Agronomic and Environmental Assessment of Cover Crops in IllinoisCrop production systems have been changing for thousands of years and new ideas and practices are being implemented every day. In recent years, the practice of cover cropping systems has come into the spot light, and though research has been in effect, the practice has been slow to take root for producers in Illinois. Benefits of cover crops primarily center around increases in soil organic matter, which can lead to higher soil productivity, but the long-term agronomic, environmental, and econom... |
6. Assessing Nitrogen Management and Claypan Soil Variability Effects on Switchgrass using Reflectance SensingThe topsoil depth or depth to the claypan (DTC) can be highly variable across the landscape for some Midwest soils. This makes managing crops on these soils difficult because their productivity can be highly variable. In some ar eas of the landscape there can be no topsoil and leave the claypan exposed (e.g., side-slope) while in other areas it can be buried (e.g., toe-slope) (Kitchen et al., 1999). Due to the high variability of theses soils, switchgrass (Panicum virgatum L.) is a potential pro... |
7. Beyond the Acre Furrow Slice: a New Era in Nutrient ManagementThe Midwest faces a pivotal shift in how we develop nutrient guidance for farmers. The long-running “build-up and maintenance” approach, built on decades-old soil-test methods, no longer aligns with today’s diverse and dynamic farming systems. Instead of anchoring decisions to soil depths tied to historical moldboard plow use, we should emphasize soil supply and plant uptake over time. Recommendations must be grounded in actual nutrient removal at harvest, on a site-by-... H.M. Brown |
8. Biochar: Waste, or Product?Nutrient losses following summer and fall manure applications result in economic and water quality problems. We tested the potential of biochar (BC) and ammonium thiosulphate (ATS) as manure additives to retain nutrients by reduci ng nitrate pool size and runoff of N and P. To determine appropriate rates to use in field expe riments, the compounds were initially added at different rates to liquid swine manure (LSM) then the slurry mixed with soil and incubated. The selected rates, based on N tra... |
9. Biological Nitrogen Suppliers for SoybeansSoybeans are known to require more N than most crops, largely due to the high N levels found in their seeds. The most important source of N for soybean plants is the biological N fixation process. However, high yields (above 70 bu acre-1) could limit the capability of this process to supply the plant's N demand. This study aims to investigate the use of non-rhizobial biological N suppliers, their ability to provide N to the soybean plants and potentially fill the N demand gap. The study w... V. Winnikes De Barros, S. Casteel |
10. Building a Corn Nitrogen Rate Database for Minnesota's Irrigated Sandy SoilsA study was conducted to determine the optimum N rate to apply for corn grown on irrigated sandy soils in Minnesota. Sandy soils in Minnesota vary in the texture of the surface fron silt loam to sand. Since 2006, 11 sites had 8 to 9 N fertikizer rates applied. The optimum N rate for the sandy sites with a silt loam surface texture ranged from 168 kg N/ha to 200 kg N/ha while the sandy surfaced soils optimum N rate ranged from 250 kg Nha to 280 kg N/ha. The silt loam surface soil sites optimum N ... |
11. Can Early Nitrogen and Sulfur Applications Sustain Soybean Yields After Cereal Rye?Cover crops such as cereal rye (Secale cereale L.) are widely promoted for their environmental benefits, including nutrient sequestration, reduced nitrate leaching, and soil conservation. However, their influence on subsequent soybean (Glycine max L.) yield and nutrient dynamics remains inconsistent, especially under varying nitrogen (N) and sulfur (S) fertilization regimes. Field trials were conducted during 2024 and 2025 across three sites in Central Illinois—Monmouth, Perry, and Urba... S. Canafoglia, G. Preza Fontes |
12. Closing the Yield Gap of Soybeans After Cereal Rye: How Limited S Application Can Affect Soybean PerformanceCereal rye is a common cover crop in the Midwest due to its overwintering biomass and soil fertility properties. Despite common adoption, research is still needed to improve soybean yield after cereal rye. Fertility management practices are needed to mitigate cereal rye immobilization of sulfur. These practices are integral for further cereal rye adoption at the farmgate. This study examines which combination of urea and/or gypsum is needed to enhance soybean yield in both cereal rye and no c... A. Antic, S. Casteel, S. Armstrong |
13. Comparison of the MRTN and Adapt-N Derived N Rates for CornNitrogen application to corn is a large determinant for high yield, and rate has important implications for economic profitability and off-field movement of nitrate-N. Nitrogen rate recommendation systems have varied over time. A popular system was yield-goal based, with grain yield multiplied by a per-bushel factor and then rate adjusted for previous crop and other N inputs. Modifications of this system are still used today in some states. Seasonal (site-year) variability in economic optimum N ... |
14. Considerations for Development of Optical Sensor Based Nitrogen Recommendation Algorithms for CornOptical sensor technology in Kansas has been used on winter wheat and grain sorghum with great success for predicting N fertilizer needs early in the growing season. However with both crops, there is a required minimum period of growth required before optical sensors can accurately detect N deficiencies. In both cases the target crop needs to have entered a period of vegetative growth where N uptake and utilization is increasing. In the case of wheat that generally corresponds to the Feekes 4 t... |
15. Corn and Soybean Response to Phosphorus Placement under Minimum Tillage SystemProducers often question the need for better fertilizer placement methods in reduced tillage systems. The objective of this study was to evaluate the effects of different placements and rates of phosphorus (P) fertilizer for corn (Zea mays) and soybean (Glycine max). The study was conducted at 3 locations from 2005 to 2012 (8 years). This paper presents results from one irrigated location. Tillage system was strip till before planting corn; and soybean was planted without previous tillage. Fert... |
16. Corn Plant Uniformity Following Shallow NH3 Placement in Precision-Guided, Pre-Plant Nitrogen ApplicationsCorn (Zea mays L.) production relies extensively on different types of N fertilizers, and anhydrous ammonia (NH 3) continues to be a dominant N s ource in much of the Corn Belt. Timing and placement of NH 3 fertilizer can affect plant-to-plant uniformity and yield of corn, and especially so when high N rates are applied and there is little time between spring pre-plant NH 3 application and planting. The effects of shallow pre-plant NH3 placement on corn plant-to- plant uniformity were investig ... |
17. Corn Residue Harvesting Effects on Yield Response to N FertilizationProducers have many choices of diverse tillage practices for their corn (Zea mays L.) production systems. However, no-till has become an important soil management practice to help reduce water and wind erosion, as well as nutrient runoff, while conserving soil moisture for crop use. No-till systems also help farmers by saving labor and time, as well as reducing farm costs due to less equipment and fuel consumption. Nevertheless, no-till production is typically more successful and has higher crop... |
18. Correlation and Calibration of the Mehlich 3 P Soil Test for Soybeans in KansasKansas currently uses the Mehlich 3 soil test for P, with a general P soil test (STP) critical level for all crops of 20 ppm (colorimetric). This critical level was established based on field research primarily with wheat in 2003. A review of the limited research data available from Kansas suggests that soybeans may not require as high a STP level as wheat for optimum yield. Therefore the objective of this study is to determine what the appropriate critical STP level is for optimum soybean prod... |
19. Critical Soil Test Phosphorus for Corn: Updates and Method Comparison in KansasPhosphorus (P) fertilizer recommendations in Kansas are currently based on legacy correlation–calibration studies and guidelines that do not account for crop-specific requirements. This lack of precision creates uncertainty in fertilizer management, raising the risk of both under-application, which limits yield, and over-application, which increases costs and environmental risk. The objective of this research was to update the critical soil test phosphorus value (CSTV) for corn (Zea... G. Roa , D. Ruiz Diaz |
20. Crop Yield Relationship to Remote Sensing Data Using Intensified Weighted Nonlinear Regression ModelsYield prediction is important for making in-season agronomic input decisions as well as for greater logistical decisions. In predicting the crop yield based on ground-based active optical sensing data, the ordinary statistical unweighted linear or nonlinear regression models are the most popular choices. However, these unweighted models may not be accurate enough for practical use because they are based on the assumption that each data point for regression is obtained with equal precision and t... |
21. Cropping System Diversification Has Strong Short-term but Limited Long-term Impacts on Soil Phosphorus DynamicsCrop diversification provides several agroecosystem benefits, yet the effects of extended crop rotations and livestock integration on soil phosphorus (P) dynamics are not well understood. We examined the effect of three cropping systems: a corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation with synthetic fertilizer (2 year), a corn-soybean-small grain rotation with red clover (Trifolium pratense L.) and composted cattle manure as a fertilizer source (3 yea... J. Kovar, C. Crespo, J. Berkey, P. O'brien, W. Huang, M. Liebman, M. Mcdaniel |
22. Determining In-season Nitrogen Requirements for Maize Using Model and Sensor Based ApproachesThere is great value in determining the optimum quantity and timing of nitrogen (N) application to meet crop needs while minimizing losses. Applying a portion of the total N during the growing season allows for adjustments which can be responsive to actual field conditions which result in varying N needs. Two methods of determining in-season N needs were evaluated, a model-based approach and a crop canopy sensor approach. The Maize-N model was developed to estimate the economically optimum N fer... |
23. Determining the Economic Optimum Nitrogen Rate for Different Cover Crop Systems Using On-Farm Precision ExperimentationSuccessful integration of cover crops into corn-soybean production systems requires adjusting interconnected management factors. Nitrogen (N) is a critical input in corn production, and because cover crops influence nitrogen dynamics, it is essential to evaluate both as an integrated system. To address this, field trials were established in two locations near Moultrie County, Illinois, in the fall of 2023 and 2024 as part of a four-year project (2024–2027) aimed at improving the underst... M. Dalla Betta, J. Jones |
24. Does Inoculant or Sulfur Improve Nitrogen Fixation in Soybean After Long-term Corn?This study evaluated the effects on nutritional dynamics and productivity in soybean, focusing on nitrogen and sulfur management in fields with more than twelve years of continuous corn in the state of Indiana (USA). Continuous corn systems are known to alter soil microbial activity, leading to a reduction in the nitrogen-fixing bacteria population, which affects the biological nitrogen fixation process in legumes, such as soybeans, which rely on those bacteria to meet their nitrogen requirem... A. Brun, S. Casteel, D. Quinn, R. Wilhelm |
25. Effect of Barley and Winter Pea Cover Crops on Nutrient Availability in No-Till CornCover crops are reported to have long-term soil health improvements, the first of which is reducing erosion. However, popular cereal cover crops, such as rye (Secale cereale), have the potential to cause a yield penalty in the following corn (Zea mays) crop. Legumes, such as Austrian winter pea (Pisum sativum), are thought to reduce this yield penalty in no-till systems. Additionally, sulfur deficiencies have been observed in some studies following cover crops. The ... E. Marsh, C. Lee |
26. Effect of Cover Crop Diversity on Nitrous Oxide Emissions from Corn–Soybean Rotations in Central IllinoisNitrous oxide (N₂O) is a potent greenhouse gas primarily emitted from agricultural soils, where nitrogen (N) inputs and soil conditions interact to drive microbial processes. Cover crops are widely promoted as a climate-smart strategy to improve soil health and nutrient cycling, yet their effectiveness in mitigating N₂O emissions may vary depending on species composition and functional diversity. This study evaluated the influence of cover crop diversity on N₂O emissions in a corn&ndash... N. Guzman |
27. Effect of Late-Applied N on Corn Dry Matter, N Content, and YieldNitrogen management of corn (Zea mays L.) may be improved by delaying N application until just prior to the rapid growth phase (approximately V6-V8). This timing is commonly referred to as 'sidedress'.� Some farmers do not sidedress because they are concerned inclement weather may delay N application beyond V8, requiring high clearance equipment to apply N and possibly reducing grain yield. However, few studies have investigated the effects of late-applied N in rain-fed production environment... |
28. Effect of Manure Sources on Soil Phosphorus DynamicsPhosphorus (P) is essential for crop production, but it also causes water quality issues such as algal blooms. Crops typically utilize only 10-20% of applied P; the remainder accumulates in soil or is eroded/leached into water bodies, resulting in reduced fertilizer use efficiency and increased risk of eutrophication. This study evaluated the effects of different organic fertilization strategies on soil P pools across two sites in Ohio. Treatments included two manure-amended sites, one receiv... J. Singh, J. Ippolito, G. Labarge, M. Rakkar |
29. Effects of Anhydrous Ammonia Application Timing on Corn Yield and ProfitabilityNitrogen (N) application timing is a critical decision for Illinois corn (Zea mays L.) producers balancing operational efficiency, economic return, and environmental stewardship. This study compared agronomic and economic outcomes of fall versus spring anhydrous ammonia applications across 19 central Illinois sites from 2013 to 2020, using a randomized complete block design with N rates from 0–361 kg N ha-1. Yield response to N was analyzed to determine agronomic optimum N ra... J. Jones, B. Link, E. Nafziger |
30. Effects of Nitrogen and Irrigation Management on Sugar Beet Yield and Nitrous Oxide EmissionsSugar beet (Beta vulgaris L.) is an important sugar-producing crop, accounting for about 55% of total sugar production in the United States. Optimizing nitrogen (N) and irrigation management is essential for achieving profitable and sustainable beet production. Excessive N application can lower sugar quality and increase nitrous oxide (N₂O) emissions, a potent greenhouse gas and ozone-depleting compound. This study evaluated the effects of irrigation and N fertilizer (urea) rates on su... S. De Silva, B. Maharjan |
31. Efficient Nitrogen Strategies for Hybrid Winter RyeEfficient nitrogen (N) management is essential to maximize hybrid winter rye (Secale cereale L.) yield. Given limited information on how N rates, application timing, and fertilizer sources affect production in the U.S. Midwest, yield responses were evaluated under various N management strategies. This experiment included a pre-plant application of 30 lb N ac⁻¹ in the fall, followed by spring applications to evaluate eight N rates (0–210 lb N ac⁻¹) and investigate the effec... M.L. Costa, J. Clark, V. Nunes, P. Sexton |
32. Emerging Trends from Wisconsin’s Nitrogen Optimization Pilot ProgramAccurately determining nitrogen (N) fertilizer requirements for crops is challenging due to the wide variability in landscapes and field management across the state. Adjusting nitrogen rates comes with a high level of risk considering over-application can reduce profits and negatively affect water quality, while under-application can prevent yield targets from being reached. Conducting field-scale, on-farm research is a practical approach to better estimating optimum N rates on a fi... M. Schauer, M. Ruark |
33. Enhanced Efficiency Phosphorus Application for a Corn-Soybean RotationPhosphorus (P) is an essential plant nutrient that is taken up by plants as inorganic ions (H 2PO4- and HPO 4 -2) found in soil solution. With higher fer tilizer costs, farmers are evaluating application rates and considering enhanced effi ciency phosphorus applications or treatments. AVAIL®(Specialty Fertilizer Products, Leawood, KS), NutriLife Max® (Advanced Microbial Solutions, Pilot Point, TX), and P ₂O ₅ Max (Rosen's Inc., Fairmont, MN) are three products that are intended to enhance ... |
34. Evaluating Classification Methods for Phosphorus Responsiveness for Fertilizer RecommendationsField crop yield responses to fertilizer applications are often uncertain, and the likelihood of a response at a given site is typically determined using correlation-based soil test methods whose accuracy is not well established. The objective of this study was to evaluate three alternative approaches to classify field sites as responsive or non-responsive to phosphorus (P) fertilization in wheat. The methods tested were: (i) a linear-plateau correlation model, (ii) a linear-plateau correlati... D. Ruiz Diaz, S. Cominelli, J. Lacasa |
35. Evaluating Commercial Nitrification Inhibitors Under Variable Soil ConditionsNitrification inhibitors (NIs) are commonly used agrochemicals designed to slow the conversion ammonium to nitrate, which has the potential to reduce environmental losses of nitrogen and improve nitrogen fertilizer recovery efficiency. However, their efficacy can be highly variable and is dependent upon soil and environmental characteristics which can vary by geographic location and agricultural production system. This experiment involved a laboratory incubation designed to evaluate the perfo... R. Roth, A. Ludolph |
36. Evaluating Near-infrared Spectroscopy for Predicting Soil Chemical Properties in KansasSoil testing is fundamental for accurate fertilizer recommendations and effective nutrient management. However, traditional wet chemistry methods are time-consuming, labor-intensive, and costly. Near-infrared spectroscopy (NIRS) offers a faster and more sustainable alternative by estimating soil chemical properties from light absorption and reflection between 350 and 2500 nm. This study aimed to develop Kansas-specific NIR calibration models to evaluate the applicability of this technique for... S. Cominelli, D. Ruiz Diaz |
37. Evaluating Soil Health Indicators in Response to Tillage, Crop Rotation, and Cover CroppingSoil health is shaped by management practices that influence soil physical, chemical, and biological properties. Conservation practices such as reduced-disturbance tillage, cover cropping, and diverse crop rotations are increasingly promoted for improving soil structure, nutrient cycling, and microbial activity. However, the extent to which these practices interact and whether newly adopted no-till systems show similar benefits to long-term reduced tillage remains unclear. This study evaluate... S. Mesman, J. Clark, V. Nunes, P. Sexton |
38. Evaluating Soybean Yield and Soil Fertility Response to POLY-4 As a Sulfur and Potassium SourceBoth sulfur (S) and potassium (K) play an essential role in soybean growth and metabolism, immunity against insect-pest and improving yield quality and quantity. Reduction in atmospheric deposition of S in soil in recent years has increased the risk of S deficiency in crops. POLY-4 is a novel S and K source containing 19% S, 14% K2O, 17% CaO, and 6% MgO with properties like slow nutrient release and high nutrient use efficiency. It can be used to address the issue of S deficiency in plants. A... R. Kaur, K. Nelson, G. Singh , G. Kaur |
39. Evaluating Spatial Attribution for Continuous Improvement of Fertilizer RecommendationsThe theory behind precision agriculture is driven on the improvement of every acre. While spatially driven recommendations have been practiced for greater than 30 years, the benefits of precision agriculture have largely not been realized. Today’s precision fertilizer recommendations have generally utilized traditional attributes (for instance: soil test phosphorus, soil test potassium, and in some application recommendations, other analyzed attributes from soil test evaluat... W. Berg |
40. Evaluation of Algorithm Thresholds for Crop Canopy Sensor-Based In-Season Nitrogen Application in CornNitrogen fertilizer is frequently the most lim iting nutrient in corn production. Typically most nitrogen is applied before plan ting. Since nitrogen can leave th e soil system fairly easily, the result can be an inefficient use of nitrogen fe rtilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regul ated spatially through the use of active crop canopy sensors. This study eva... |
41. Evaluation of Novel Soybean Inputs to Enhance YieldThe U.S. Average soybean yield was 43.5 bushes/acre in 2010 (www.nass.usda.gov), with reports of much higher yields in some areas. With large yield differences among years and locations, as well as some high-profile marketing and publicity campaigns promoting 'high yield' management, producers are interested in any inputs or management practices that might improve yields. High soybean prices at present and interest in finding ways to increase yield have led to emergence of a number of new produc... |
42. Evaluation of Wavelength from Ground-Based Active Optical Sensors for Corn Yield Prediction in North DakotaGround-based active-optical (GBAO) crop sensors have been used successfully to predict crop yield when used during early growth stages. The objective of this study was to evaluate two GBAO sensors wavelengths regarding their usefulness under North Dakota corn (Zea mays, L.) growing conditions. Thirty experimental sites were used in North Dakota to conduct N rate trials on corn during 2011 and 2012. All sites were designed as randomized complete blocks with four replications and six nitrogen (N) ... |
43. Fate of 15N-Labeled Urea Applied In-season for Corn in Eastern North DakotaNitrogen (N) fertilizers represent a major investment for North Dakota cropping systems as evidenced by the 890,000 tons of N used by producers in 2024 alone. If these inputs are to be beneficial to the producer and not harmful to the environment, they must be managed efficiently. To evaluate the efficacy of split-N applications, 15N-labeled fertilizer was applied to three different soil types in eastern North Dakota, including an irrigated sand, a smectite rich clay, and clay loam... M. Culpitt, K. Griesheim |
44. Fertilizer Derived Nitrogen Dispersion in Minnesota Corn with Rye and Kura Clover Cover CropsWhile ideally all fertilizer nitrogen (N) is utilized by crops, much can be lost to the environment as nitrate (NO3), nitrous oxide (N2O), or ammonia (NH3). To enhance agronomic systems and mitigate environmental N dispersion, best management practices can be utilized. Here, urea was applied to continuous corn at 250 kg N/ha or a 0 kg N/ha control, and with select cover crops (no cover, winter rye, kura clover) to assess practices that may result in optimal fe... J. Kastenbauer, F. Fernández, V. Sharma, R. Venterea, J. Spackman |
45. Field Correlation and Calibration of Soil-Test Phosphorus and Potassium for Corn and Soybean in IllinoisEffective phosphorus (P) and potassium (K) soil-test interpretation and fertilizer guidelines require each soil test to be field correlated with crop yield response to fertilization and calibrated to provide expected response probabilities. University of Illinois P and K guidelines require updates to reflect routinely used soil-test methods and current cropping systems. Field studies were established at seventeen sites across Illinois to correlate soil-test P and K with corn and soybean respo... F. Bardeggia, J. Jones |
46. From the Ground Up: a Farmer-Led On-Farm Research Evaluating the Potential of a New Fertilizer Source for Nitrogen in Pastures for MissouriThis research is a part of a transdisciplinary network of farmers leading on-farm research and innovation groups across Missouri, where farmers are leading the design and implementation of nitrogen (N) fertilizer treatments. The Objective of this on-farm research trial in southwest Missouri is to determine whether green lightning fertilizer technology can fulfill the N requirement of pasture in a more economical and sustainable way than the conventional sources of N. The cost of N f... K. Deep, R. Carson, G. Singh, J. Vredenburgh |
47. FRST Lime Project: Results of Pilot Study of Lime Source, Lime Rate and Incubation Time on Neutralization of Soil AcidityManagement of soil acidity plays a critical role in the agriculture across North Central Region. The Fertilizer Recommendation Support Tool (FRST) group has launched a national project to develop new lime recommendations and has collected 144 soils of which 38 soils from the North Central Region. A pilot lime study was initiated to assess the effect of lime source, lime rate and incubation time on neutralization of soil acidity. Three acid soils were selected from the Agricultural Proficiency... B. Miller |
48. Genotype Specific Management for Nitrogen Use Efficiency in Kentucky Soft Red Winter WheatThe complex interaction of genotype x environment x management (GxExM) that defines crop yield is often only explored with research on a single genotype or a select few genotypes. Improvements in crop management and understanding local adaptation to climate variability will require a broader understanding of specific genotype interactions with management systems across multiple environments. A multi-year study investigating the potential for variety specific management systems based on phenotypi... |
49. Geographic Trends in Alfalfa Stand Age and Crops that Follow AlfalfaTo gain perspective on alfalfa-annual crop rotations in the upper Midwest, USDA-National Agricultural Statistics Service cropland data layers and Soil Survey Geographic Database layers were combined for six states (North Dakota, South Dakota, Nebraska, Minnesota, Iowa, and Wisconsin) and seven years (2006-2012). Soil texture and geographic location both significantly affected the length of the alfalfa phase (stand age), and alfalfa stand age, soil texture, and year all significantly affected the... |
50. How Do Cover Crops, Nitrogen Rate and Cropping System Affect Nitrate Loss in Tile Drainage Water?A field research study was conducted on clay loam soil in Waseca Minnesota. The objectives were to quantify the effects and interactions of cover crops, nitrogen (N) fertilizer rates and cropping system on corn production and nitrate-N concentration and loss in tile drainage water. Cover crop treatments [cereal rye and a blend of annuals (oat, forage pea and radish)] were drilled soon after corn silage harvest each fall. Nitrogen treatments were split-applied at planting and V3 growth stage. ... J. Vetsch, A. Cates |
51. Hybrid, Plant Population, and Nitrogen Interactions in CornCharacterizing hybrids by their response to both plant population and N response will be needed to help make variable-rate population and N rate work. We planted four corn hybrids at three sites in Illinois over two years, using combinations of 18,000, 34,000, and 50,000 plants per acre 0, 80, 160, and 240 lb N/acre. Across three environments where shortage of water reduced yields, 50,000 plants/acre yielded less than the two lower populations, both of which yields about the same. There was lit... |
52. Identification of Reasons for High Temporal Soil-Test Potassium VariationExtensive research has focused on potassium (K) fertlization and soil K testing during several decades in the Corn Belt. IN Iowa, more t han 200 conventional or on-farm strip trials were conducted since the iddle 1990s until the early 2000s. Results of this research were used to update Iowa State University (ISU) K recommendations in 1999 and in 2002. In spite of increasd knowledge about soil-test K calibration, K fertilizer placement meethods, and needed K fertilizer rates, this research demons... |
53. Impact of Ammonia Reduction Management Practices in Land Applied Manure on Nitrogen Losses and Nitrogen Use EfficiencyDairy manure is a valuable nitrogen (N) source in crop production, but N losses through volatilization and leaching diminish its nutrient value and pose environmental risks. Proper manure management practices can enhance nitrogen use efficiency (NUE) and mitigate these environmental concerns. This ongoing two-year field study evaluates different manure application methods and assesses their tradeoffs regarding N leaching and NUE. The study involves six experimental treatments, each applying 9... J. Bukomba, R.A. Larson, M. Ruark, X. Zhu-barker, N. Rayne |
54. Impact of Phosphorus Source and Timing on Corn Yield and Root GrowthPhosphorus (P) management is critical in maize production due to limited mobility, solubility, and stratification in soils. This study evaluates P application techniques with regard to maize grain yield, total P uptake, and root distribution. Our hypothesis was that applying P as a side dress in a low P soil at a low dose equal to plant uptake can compensate for not maintaining soil test P at the critical level, providing sufficient P during peak demand and sustaining high yields. A gre... A. Beltrame, C. Penn, D. Quinn, M. Williams, C. Zhang |
55. Impacts of Management Practices and Soil Properties on Free-Living Nitrogen Fixation in Southeastern South DakotaModern agriculture relies heavily on synthetic nitrogen fertilizer, raising environmental concerns due to overuse. Biological dinitrogen (N2) fixation offers a sustainable alternative, with free-living diazotrophs playing a crucial role alongside well-known symbiotic nitrogen-fixing bacteria. Recently, interest in free-living nitrogen fixation (FLNF) has grown due to its potential contribution to sustainable agricultural practices. However, there is limited scientific data on FLNF ... L. Galvan Nuevo, A. Blume, V. Nunes |
56. Improving Corn Grain Yield and Reducing Nitrate-N Leaching with Urease and Nitrification InhibitorsSustainable corn (Zea mays L.) production requires proper nitrogen (N) management to optimize yield and minimize negative impacts of N losses on water quality. Nitrification inhibitors could be a viable strategy to synchronize N availability and corn N demand and decrease N loss through nitrate-N leaching. A field study was laid out in a randomized complete block design with five replicates at the Belleville Research Center (2023-24) and the Agronomy Research Center (2024-25), IL, wi... S. Koduru, O. Guzel, J. Mcgrath, M. Javid, O. Ola, E. Brevik, A. Sadeghpour |
57. Industrial Hemp Response to Nitrogen Applications in MissouriIndustrial hemp (Cannabis sativa L.) is gaining attention as a multipurpose crop for fiber, grain, and biomass, but research-based region-specific guidelines on nitrogen (N) management are limited. To address this gap, field experiments were conducted at two locations (Albany, Novelty) in northern Missouri in 2024 & 2025 to evaluate the effects of N applications on industrial hemp growth, biomass, and grain yield. The experiments were laid out as a randomized complete block ... A. Nain, G. Kaur , K. Nelson, G. Singh, M. Davis |
58. Influence of Nitrogen Fertilization Frequency and Rate on Nitrous Oxide Emissions in Winter WheatManaging nitrogen (N) fertilizer effectively is important for reducing nitrous oxide (N2O) emissions in farming systems. This study examined the effect of N application frequency and rate on winter wheat (Triticum aestivum L.) grain yield, total N₂O emissions, and yield-scaled N₂O emissions. The experiment was conducted at the Agronomy Research Center (ARC), Southern Illinois University, Carbondale. A randomized complete block design (RCBD) was used ... O. Ola, O. Guzel, K. Gage, K. Williard, J. Schoonover, S. Mueller, E. Brevik, A. Sadeghpour |
59. Influence of Nitrogen Management and Precipitation on Sorghum Nitrogen Use Efficiency in KansasGrain sorghum (Sorghum bicolor L. Moench) is a key crop in Kansas which can benefit from optimized nitrogen (N) management that enhances yield while minimizing N losses. Understanding the relationships among physiological efficiency (PE), recovery efficiency (RE), and agronomic efficiency (AE), as well as their interactions with climatic factors such as precipitation, is essential for improving nitrogen use efficiency (NUE). Experiments were conducted across five r... M. Platero, D. Ruiz Diaz |
60. Influence of Soil Amendments and Topographic Position on Winter Wheat Heavy Metal UptakeField crop heavy metal accumulation poses a major challenge for reducing food contamination and is governed by complex interactions between soil physical and chemical properties, climatic conditions, and intrinsic plant traits. Addressing these challenges requires an understanding of heavy metal accumulation during crop development and effective pre-harvest field mitigation strategies. Two winter wheat (Triticum aestivum L.) field studies were conducted in Michigan focusing on 1) fer... K. Steinke, M. Suplito, Z. Hayden |
61. Integrating NDVI and Plant Tissue Analysis As Decision Support Tools for Nutrient Management in Winter WheatEfficient nitrogen (N) management is critical for improving winter wheat grain yield and protein content while minimizing costs and environmental risks. Remote sensing indices, such as the Normalized Difference Vegetation Index (NDVI) and physiological indicators, like flag leaf N content, have been proposed as predictors of crop performance that could support in-season N management decisions. This study evaluated the relationships between NDVI measured at multiple growth stages, flag leaf N ... J. Leiva, D. Ruiz Diaz |
62. Interpreting Soil Health Test Results to Guide Management for Missouri Row CropsSoil health determines long‑term productivity, nutrient cycling, water retention, and resilience in row‑crop systems. Missouri-specific, data-driven framework for interpreting six complementary soil health indicators—total organic carbon (TOC), permanganate-oxidizable carbon (POXC), 3-day soil respiration, wet aggregate stability (WAS), autoclaved citrate-extractable (ACE) protein, and potentially mineralizable nitrogen (PMN)—was developed by the University of Missouri Soil He... G. Singh , K. Nelson, M. Parvej, D. Brandt, R. Myers |
63. Investigating Potassium Fertility in Indiana: K Rates and Nutrient InteractionsAdequate potassium (K) nutrition is critical for optimal plant growth and yield production in both corn and soybeans. Ongoing trials across the state of Indiana have been investigating K rate response in corn and soybeans in different environments. Treatments range from 0-180 lbs K2O/ac as potash. Results from these studies will be discussed. Additionally, new in 2025, NxS and NxK trials were conducted to investigate the effect of K nutrient interactions on corn yield. Treatments i... D. Quinn, A. Helms, M. Bourns |
64. Investigating the Need for Sulfur for Kentucky Wheat ProductionSulfur (S) deficiencies in Kentucky wheat production are increasing due to a reduction in atmospheric S deposition, greater removal in grain and forage, and less S contamination in phosphorus fertilizers. The University of Kentucky currently does not provide S recommendations based on S soil test results. This is largely due to the Mehlich 3 soil test extractant not being correlated or calibrated for S response in Kentucky crops and the lack of S responsive fields. Surveys and studies were co... E. Ritchey, J. Grove |
65. iPhone Apps: Corn Nitrogen Fertilizer Rate Calculator and Nitrogen Fertilizer Price Comparison CalculatorAs communications technology advances, there is a need for Extension to deliver information and decision- making tools that leverage these new technologies to engage existing and new clientele groups in new wa ys. Smart technologies allow ac cess to pertinent information on-the- go and out in the field, right when it's needed. ... |
66. Irigated Soybean Response to Nitroen Applied During Early Pod FormationHigh yield soybean ( Glycine max L.) has a high rate of N uptake during grain fill with maybe 2/3 of the N derived from the atmosphere. The rema ining needs to come from the soil. Previous research has found that the probability of response to N applied at early pod development (R3) for yield trials, including 44 with mean yield >60 bu/A, we re conducted in Nebraska to determine effect on soybean yield of applying N and S to the soil at R3. With 27 lb/A N applied and >60 bu/A yield, mean yield ... |
67. Linking Soil Properties and Weather Variability to Nitrogen Fertilizer NeedsSoil Nitrogen (N) availability is known to be affected by weather and soil characteristics. Current fertilizer recommendations are generally based on yield goals, soil type, and past productivity; however, these methods frequently fail to account for the constantly changing interactions between soil biological, chemical, physical and weather variables that influence N availability. This limitation increases uncertainty in estimating the economic optimum nitrogen rate (EONR), potentially reduc... S. Dangal, J. Clark, P. Kovacs, V. Nunes, C. Graham |
68. Managing Riparian Buffers to Improve Soil Structural PropertiesFifty-five percent of Kentucky's stream impairments have been attributed to agriculture. Riparian buffer management may improve buffer effectiveness and reduce agricultural contaminants impairing water quality. Three mowing regimes and one native grass establishment regime were imposed in the riparian buffer zone surrounding a tributary of Cane Run Creek in Fayette County KY. Treatment plots measured 10m x 15m, with 10 replications of each treatment. One year after treatment, root biomass, soil ... |
69. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant-available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syste... |
70. Maximizing Yield, Income, and Water QualityA program sponsored by the Illinois Council for Best Management Practices (CBMP) to provide local growers an estimate of the location, form, and concentration of plant- available N remaining in the soil. Plant-available N at a point in a field and a point in time can be estimated utilizing this technique and provide information that may help minimize environmental impact by improving harvest yield and maximizing nitrogen utilization. (This is not to be used as a stand-alone N recommendation syst... |
71. Maximizing Yield, Income, and Water QualityN-WATCH is a management tool designed for N Management Systems to inventory, track, and verify plant-available N in the soil. N Management Systems hedge the risk of N loss by splitting up the N application following the 4Rs of Nutrient Management (Right source, Right rate, Right time, and Right place). It is all about Minimizing environmental impact by Optimizing harvest yield, and Maximizing nutrient utilization. It is all about focusing on M.O.M. Who is eligible: Ag Producers that are adoptin... |
72. Maximizing Yield, Income, and Water QualityTo improve farm profitability and minimize environmental impact of nitrogen (N) use by reducing N losses and increasing harvest yield. Nitrogen Management System: A planned approach to N use that achieves better plant utilization and higher harvest yield with less environmental loss. It promotes a multiple application approach to N Management. It reduces early N application rates while emphasizing post-emerge N nutrition. It is about making incremental N applications that will Minimize environm... |
73. Maximizing Yield, Income, and Water QualityThose involved with Midwest production agriculture are aware that applications of nitrogen fertilizer can have unintended consequences upon water quality. It is our focus to minimize the potential of such environmental risks by working together to optimize harvest yields, and to maximize nitrogen utilization through the use of science-based initiatives, such as development of nitrogen management systems and N-WATCH. Sustainability of voluntary efforts to minimize the environmental impact of nitr... |
74. Micronutrients as Starter and Foliar Application for Corn and SoybeanCorn and soybean production under high yield environments can benefit from the combined use of starter and foliar fertilization, including macro and micronutrients. The objective of this study was to evaluate corn and soybean response to starter fertilizers in combination with foliar application of macro and micronutrients to maximize yield s. Experiments were conducted in 2010 and 2011 at two locations for corn and soybean under irrigation. Starter and foliar fertilizer treatments were applied ... |
75. Minimizing Nitrate Loss from Manure-amended Wisconsin Sandy SoilsThe impact of dairy manure application on nitrate leaching was evaluated at two sites with no manure history. Manure treatment (separated-solid manure, separated-liquid manure, separated- liquid manure plus a nitrification inhibitor, and two treatments with no manure) was the main plot. Each manured plot was split into six subplots with three receiving a single sidedress fertilizer application of 0, 56, or 112 kg N ha -1 while the others had two sidedress applications totaling 112 kg N ha-1 with... |
76. Mitigating Phosphorus Movement from Agricultural FieldsAgriculture is often cited as the primary factor for the high P loads polluting Lake Erie and Ohio�۪s watersheds, but the contributions of agriculture as a system, a combination of tillage, best management practice (BMP) and fertilizer source rather than an industry is unknown. This study supplied either commercial fertilizer or poultry litter to tilled or no-till production systems with their corresponding BMPs of incorporation and cover crops, respectively, to determine the P lost via surf... |
77. Nebraska's Natural Resources Districts: Experiences in Managing Nitrate in Ground WaterNebraska's 23 Natural Resources Districts (NRDs or Districts) were formed in 1972, and are quasi-local entities which are charged with various responsibilities in managing the State's soil and water resources. The Districts are governed by locally-elected Boards of Directors, managed by professional staff, and have independent taxing authority. They have broad responsibilities in ground water quantity and quality management, and one of the major efforts NRDs have engaged in over the past several... |
78. Nitrogen Effects on Forage Utilization and Economic Returns in Grazing and Haying SystemsForage productivity and profitability are essential in both grazing and haying systems. This study evaluated haying and rotational grazing systems and nitrogen rates compared to overseeding birdsfoot trefoil (Lotus corniculaatus; BFT) on an Armstrong Loam (Aquertic Hapludalfs). Forage biomass was consistently higher under grazing, with its advantage widening as N increased. Both systems displayed diminishing marginal returns, but grazing achieved greater fertilizer efficiency, produc... E. Oppong Adjei, R. Carson, J. Lory, K. Nelson |
79. Nitrogen Fertilizer Additives, Which Ones Work?Nitrogen fertilizer additives were evaluated in nine different studies. In the first study, Nutrisphere had no effect on urea hydrolysis when applied with a urea solution. In a second study, Nutrisphere had no effect on nitrification when applied with a urea solution. In a third study with urea granules, Nutrisphere had little effect on ammonia volatilization. In a fourth study with urea granules, Nutrisphere had no effect on nitrification. In a fifth study, Nutrisphere was found to be less effe... |
80. Nitrogen Fertilizer Application Consultation Tool (N-FACT)The N-FACT is a decision support web tool that leverages data from the Iowa Nitrogen Initiative on-farm nitrogen rate trials with cropping systems modeling. The web tool was released in February 2025 (https://n-fact.ag/start). The web tool summarizes results on optimum nitrogen fertilizer rate for corn from hundreds of on-farm trials across Iowa. Additionally, the web tool allows users to select a county, crop rotation, planting date, fall... S. Archontoulis |
81. Nitrogen Loss from Sprinkler Applied Beef Feedlot EffluentLoss of nitrogen from sprinkler applied beef feedlot effluent can be costly for both the producer and the environment. Sprinkler application of effluent is common throughout the Great Plains, though little work has focused specifically on N losses from beef feedlot effluent. We quantified ammonia (NH 3) and nitrous oxide (N2O) losses from beef feedlot effluent applications under field conditions including variations in soil pH, soil water content, ammonium (NH 4+) concentration of the effluent, ... |
82. Nitrogen Management of Temporary Waterlogged Soil to Improve Corn Production and Reduce Environmental N LossDuring the 2011 growing season excessive soil moisture in the Unites States accounted for at least 30% of the total crop loss to environmental stresses resulting in more than $3 billion dollars in insurance indemnities paid to farmers. The objectives of this study were to: (i) assess grain yield and N silage uptake for both rescue and non-rescue treatments of different enhanced efficiency products, (ii) determine soil N content among treatments throughout the growing season, and (iii) evaluate P... |
83. Nitrogen Management: Unraveling the Effect of Timing and FormImprovement of nitrogen use efficiency by co rn production would decrease the potential for nitrogen loss into the environment. A study ha s been conducted in Ames, Iowa on 16 different forms and rates of nitrogen in both a continuous corn and corn-soybean production systems. There were differences among treatments; howeve r, the most consistent treatment was the SuperU applied as a 150 lb A -1 preplant or as 50 lb A-1 preplant and 100 lb A-1 sidedress and UAN with Agrotain adde d to both the 5... |
84. Nitrogen Rate Revisions for Corn in North DakotaNitrogen rates in North Dakota have been based on a yield-goal or yield-potential formula for over forty years. The currently published formula (Franzen, 2010) is: Recommended N rate = (Yield Potential, bushels per acre) X 1.2 less N credits from previous crops and soil test nitrate to 2 feet in depth. A yield-based strategy was practical when N costs were relatively low and yields in North Dakota were at most 100 bushels per acre. However, due to improved germplasm developed at North Dakota Sta... |
85. Nitrogen Timing and Nitrification Inhibitors for Corn in KansasAnhydrous ammonia is a common Nitrogen (N) source used for corn production in Kansas. Two common mechanisms of N loss in corn production in Kansas soils are denitrification and leaching. By minimizing these losses, producers can maximize yield with lower input use and have less impact on the environment. Time of application, particularly fall vs. spring application can have significant impact on N loss, particularly in some soils. The use of nitrification inhibitors (NI) with anhydrous ammonia ... |
86. Nutrient Deficiency Diagnostic Training with Field and Hydroponically Grown CropsThe Manitoba Crop Diagnostic School was initiated in 1995 and annually provides training for 350 - 400 field agronomists over a two week period in mid July. Symptons of nutrient deficiencies, other than Nitrogen (N), have proven difficult to demonstrate on the fertile high organic matter loam texturd soiles of the Carman Researh Station. The following techniques have been developed to demonstrate many of the macro and micronutient deficiencies which may occur in prairie crops.... |
87. Nutrient Management Studies in Bio-Fuel Cropping SystemsResearch was conducted to determine the effect of nutrient management practices on bio-fuel crop production, and to evaluate long term effects of bio-fuel crop production on selected chemical, physical and microbiologi cal properties. Experimental plots for research on bio-fuel crops production were established in 2008 at two sites in Missouri. The experimental design was an 8x3 factorial laid out in a sp lit plot design. The main plots were eight bio-fuel cropping systems including: 1) continu... |
88. On-Farm Assessment of Nitrogen Use and Management in Irrigated Corn Production in NebraskaHigh-yield irrigated crops have large nitrogen (N) requirements. For example, N uptake of a corn crop that yields 207 bu ac -1 (~13 t/ha) is about 180 lb N ac-1 (200 kg N ha-1). The amount of N that is not provided by indigenous sources (mineralization of previous crop residue and soil organic matter) needs to be supplied by crop producers through N fertilizer. High-yield irrigated corn accounts for 74% of total annual corn production of 1260 million bushels in Nebraska. With approximately 70,00... |
89. Optimizing Nitrogen Application in Corn with and Without a Nitrification InhibitorDetermining an accurate nitrogen (N) recommendation for corn production presents significant challenges due to its complexity with N transformation and losses. A careful diagnosis and decision making is required for optimizing the N management in corn. Therefore, a three-year (2023-2025) field study was conducted to evaluate the effects of varying nitrogen (N) application rates and timings with the use of a nitrification inhibitor (NI) on corn grain yield and productivity. The study was arran... R. Paul, G. Singh , K. Nelson, G. Kaur , M. Parvej |
90. Optimizing Nitrogen Inputs in Malting Barley ProductionIn 2024, North Dakota produced 14.6% of the United States 144 million bushels of barley. Nitrogen (N) availability is a key factor influencing production and as sustainability becomes a priority, reducing greenhouse gas (GHG) emissions through enhanced efficiency fertilizer is essential. This study evaluated the effect of N application source on spring barley (Hordeum vulgare L.) grain yield and quality, as well as estimating N use efficiency (NUE). Field trials took place in 2025 at... B. Goettl, M. Martinez De Souza |
91. Overview of Manure Handling on Steroid Movement in Agricultural Fields from Beef Cattle SystemsManure generated from concentrated animal feeding operations may serve as a source of steroids in surface water and potentially in groundwater. The objectives of this research were to determine the amount of steroids and metabolites in runoff from beef cattle production pens, and from runoff and leaching from crop production fields. Cattle were fed a synthetic progestagen, MGA or melengestrol acetate and treated with zeranol, trenbolone acetate, and estradiol implants, while a second group was n... |
92. Phosphorus and Potassium Removal and Leaching from Residue in Corn and SoybeanResearch is continually being conducted to adjust and update recomm endations for phosphorus (P) and potassium (K), and to be tter understand relationships betw een nutrient application, grain yield, nutrient removal with harvest, and soil-test values. Studies in Iowa and other states of the north central region have been used to develop guidelines about P and K removal rates in corn and soybean for use together with soil testing information to manage P and K. There is very large temporal varia... |
93. Phosphorus Fertilizer Management: Implications on Crop Yields and Soil P BudgetsRecent volatility in fertilizer prices, declining commodity values, and increasing water quality concerns have intensified scrutiny around phosphorus (P) management decisions in Ohio. In response, we initiated a field trial to evaluate crop yield response and soil phosphorus budgets under various P application strategies within a corn–soybean rotation during the 2024 and 2025 growing seasons. The study investigated two P application timings (fall and spring), two fertilizer sources (tri... M. Rakkar, B. Robinson |
94. Picking the Right Nitrogen Recommendation Tool to Improve NUE and Water Quality in NebraskaThe comparison of static versus dynamic nitrogen (N) recommendation tools has gained significant attention for enhancing N management in the U.S. Midwest maize production. However, both approaches have limitations in performance under variable field conditions. This two-year study (2021–2022) evaluated the agronomic, environmental, and economic outcomes of a static Nebraska Yield Goal (NE YG) tool against four dynamic N tools: Maize-N, canopy reflectance sensing, Granular, and Adapt-N. ... J. Iqbal, A. Singh |
95. Predicting Nitrogen Response by Winter Wheat Using Soil Health and Soil Microbiome IndicatorsEfficient nitrogen (N) management is critical for improving profitability and sustainability in winter wheat production systems of western South Dakota, where soils and growing conditions vary widely. Current fertilizer recommendations rely heavily on soil nitrate-N, often overlooking contributions from organic N sources and soil biological activity. This project aims to refine N fertilizer recommendations by integrating soil health indices (SHIs) and soil microbiome analysis as predictors of... C. Graham, R. Jain |
96. Quantifying Risk in Nitrogen Management through On-Farm EvaluationsThe process of nitrogen (N) management in corn (Zea mays L.) production is often reduced to finding ways to manage various risks. These risks include common difficulties of quantifying soil N availability, avoiding N fertilizer losses, and predicting the impact of weather before and after fertilizer applications. This poster provides a synopsis of several recent on-farm evaluation studies conducted across Iowa. These studies were designed and executed to identify management, soil, and weather f... |
97. Relationship between Nitrogen Rate and Weed Removal Timing on Corn YieldWeeds actively compete for nitrogen in corn grain production systems. Field studies were conducted in 2009 and 2010 at the Michigan State University Crop and Soil s Research Farm in East Lansing , MI to evaluate the effect of N application rate and weed removal timing on grain yield . Treatments included four preplant incorporated rates of urea (0, 67, 134, and 202 kg N ha - 1 ) and four weed removal timings (5, 10, 15, and 20 cm) based on average weed canopy height. An additional season- long w... |
98. Role of Winter Rye Cultivar and Seeding Rate in Managing Residue and Nitrogen Availability in Corn Cropping SystemsWinter cereal rye (Secale cereale L.) (WCR) is the most widely used cover crop in Illinois and is recognized as one of the most effective in-field practices to reduce nitrate-N and phosphorus (P) losses to the Mississippi River Basin (MRB). However, adoption of WCR prior to corn (Zea mays L.) remains limited due to challenges such as stand establishment and nitrogen immobilization. Management strategies, such as selecting appropriate cultivars and optimizing seeding rates, m... S. Babaei, C. Kula, Y. Samadi, E. Brevik, A. Sadeghpour |
99. Searching for Inputs to Increase Soybean YieldCommodity prices and production costs are both at higher levels than in prior periods, encouraging growers to maximize returns by managing costs and raising yields. We conducted experiments at three Illinois sites in 2012 to evaluate foliar fertilizer, foliar insecticide, lactofen herbicide, seed treatment, foliar fungicide, foliar fungicide + foliar insecticide, cytokinin, , and fertilizer N, alone or in combinations of factors, including some deletion' treatments. Serious drought through the ... |
100. Sensor-based Nitrogen Management Affects Corn Production and Environmental N FootprintsTo improve air and water quality, nitrogen (N) management in corn production systems should shift from the current N decision support system [maximum return to N (MRTN)], which suggests a single rate N addition, to sensor-based (GreenSeeker) active N management (variable N rate approach). Single rate N recommendations often result in under- and over-N addition and either increase environmental N losses or cause corn yield penalty. Our objectives were to evaluate corn optimum nitrogen N requir... A. Sadeghpour, O. Guzel, M. Guzel, J. Mcgrath, O. Adeyemi, E. Brevik, S. Koduru |
101. Slow-Release Fertilizer Effect on Groundwater Nitrogen Concentration in Sandy Soils under Potato ProductionCurrent nitrogen (N) fertilizer management practices for potato farming have led to elevated levels of N in the local groundwater. Slow-release fertilizer, specifically Environmentally Smart Nitrogen® (ESN®) polymer coated urea (PCU ) may reduce the amount of N leaching to groundwater; however no field scale studies have been performed in Wisconsin to validate these assertions. Field experiments were conducted at the Hancock Agricultural Research Station using Russet Burbank potato, planted i... |
102. Soil Health Responses to Interseeded Cover Crops and Nitrogen Strategies in the Northern Corn BeltCover cropping and nitrogen (N) management are often promoted for improving soil health, yet their combined influence under interseeded systems in temperate regions remains less understood. To address this gap, a field study was conducted in South Dakota at two no-till corn–soybean rotation sites (Brookings and Beresford) established on clay loam soils. Cover crop treatments included a no cover, a single grass species, and a multi-species mixture of grass and broadleaf species interseed... J. Clark, S. Kodali |
103. Soil pH and Crop Response to Lime Source and TillageAg lime recommendations are based on soil pH, buffer pH, and neutralizing index or effective calcium carbonate equivalent (ECCE) of the lime to be used (Laboski and Peters, 2012). Determination of neutralizing index may vary by state and is often codified in state regulations related to the sale of ag lime. In Wisconsin, the neutralizing index of a lime is a function of purity (calcium carbonate equivalent) and fineness (particle size) (Schulte et al., 2005). Pelletized lime is typically calciti... |
104. Soybean Production Research: A National ApproachU.S. soybean growers are looking for alternative methods to increase soybean yields and recent increases in commodity prices have given producers more freedom to invest in additional crop inputs or products. Unfortunately, quality data from studies addressing multiple contemporary inputs is scarce. The objective of this work was to evaluate the effectiveness of combined soybean inputs on seed yield. These high input systems were tested in six states to evaluate their value across a broad geograp... |
105. Soybean Response to Sulfur Placement and Starter Fertilizer ApplicationReduced rates of early season nutrient mineralization from earlier planting dates, increased nutrient removal from greater yields, and reductions in atmospheric sulfur (S) deposition have increased concern regarding S availability for optimal soybean (Glycine max L.) growth. A field study was established to determine the effects of 25 lbs. S per acre with or without starter fertilizer consisting of 20 lbs. nitrogen (N) per acre and 50 lbs. P2O5 per acre on soybean grain yield and quality. Main p... |
106. Soybean Response to Tillage, Row Spacing and Nutrient Management Practices in Southern IllinoisConservation tillage improves long-term soil health and water quality but may reduce early soybean (Glycine max L.) growth due to cooler, wetter soils and limited nutrient availability. This study evaluated integrated management strategies, including tillage, row spacing, and starter nitrogen (N) and sulfur (S) fertilization, to optimize soybean performance under Illinois conditions. Field trials were established in 2024 in southern Illinois. Two split-plot experiments were conducted... E. Brevik, A. Sadeghpour, F. Rolle, D. Schaefer, G. Preza Fontes, M. Javid |
107. Soybean Yield Response to Nitrogen and Sulfur Starter Fertilizers Under Conservation TillageContext: No-tillage and cover crops adoption remain limited across the U.S. North Central region due to concerns about potential yield penalties in cash crops. High residue levels can slow soil warming and mineralization and promote nutrient immobilization, often leading to limited early-season nitrogen (N) and sulfur (S) availability for soybean. Objective: Evaluate soybean grain yield response under different tillage systems and assess the potential of N and S starter fe... F. Rolle, G. Preza Fontes, D. Schaefer, J. Vossenkemper |
108. Sulfur and Micronutrient Fertilization for Wheat Production in KansasGenetic advances in wheat (Triticum aestivum) and increased yield potential may require changes in fertilization programs including the addition of secondary and micronutrients. The objective of this study was to evaluate wheat response to sulfur and micronutrient fertilization and evaluate soil testing and tissue analysis as a diagnostic tool. Seven locations were established in 2012 and 201, all locations were established in under dryland conditions (four locations presented in this paper). Fe... |
109. Sulfur Cycling from Corn in Corn-Corn and Corn-Soybean RotationsSulfur fertilizer requirements for corn grown on medium and fine textured soils have increased over the past ten years. The effect of sulfur rate and timing on the potential for sulfur cycling and carryover within a two year crop rotation, corn-corn and corn-soybean, were studied. Sulfur was applied as ammonium sulfate on the soil surface at planting and the V3-V5 growth stages at rates of 0, 10, 20, 30, and 40 lbs of S per acre during the first cropping year. Each plot was divided in two prior ... |
110. Survey of the Tissue Nutrient Status of Winter Wheat in KentuckyA field survey conducted in western Kentucky (KY) was initiated to determine if University of Kentucky soil fertility recommen dations for winter wheat production was adequate. Twenty- nine fields in 15 western KY counties were iden tified by county extension agents for sampling. Soil and tissue samples were collected for anal ysis in a 150 foot by 150 foot sampling area. Approximately 100 flag leaf samp les were collected, air-dried, ground, and analyzed for N, P, K, Mg, Ca, S, B, Zn, Mn, Fe, ... |
111. Switchgrass Response to Nitrogen: Trade-offs between Quantity and QualityIn 2009 and 2010, a study was conducted at four loca tions in southwest Wisconsin to determine optimal nitrogen (N) fertilizer rates and harvest timings for switchgrass quantity and quality. The study was conducted as a randomized complete bloc k, split plot design with five main plot treatments (0, 56, 112, 168, and 224 kg ha -1 of N) and three split plot treatments (mid-fall, late- fall, and early spring harvest). Dry matter (D M) yields increased between 2009 and 2010 and were most often max... |
112. Technology, Innovation, and the Future of Soil FertilityThis panel will focused on how technology is being used in the practice of soil fertility and nutrient management. Panelists will also discuss how they’ve incorporated new and old soil fertility concepts into their approach to guiding fertilizer use. Lastly, we will discuss where soil fertility is going as a scientific discipline. ... H.M. Brown, W. Berg, R. Mullen |
113. Terrace Construction Effects on Soil Fertility, Texture and Apparent Electrical ConductivityThe Midwestern United States is extensively dominated by sloping terrains, where terraces are recognized as a tool to minimize soil erosion. The process of terrace construction involves heavy machinery and extensive soil profile manipulation, which may alter soil fertility and texture. This study evaluated the changes in soil fertility, texture, and apparent electrical conductivity (ECa) following the construction of eight broad-based terraces in northern Missouri. Geo-referenced soil samples... C. Bansal, G. Singh , G. Kaur , K. Nelson |
114. The Effects of 40 Years of Tillage and Fertility Practices on Soil Organic Carbon and Fungal PopulationsSoil organic carbon plays an integral role in long-term soil productivity. In cultivated systems, potential productivity is directly related to soil carbon concentrations, highlighting the need to protect current organic matter levels and develop management practices that will enhance soils with declining soil carbon contents. There have been variable responses in soil carbon levels to both tillage and fertility treatments. Tillage alters the physical and chemical properties of the soil environm... |
115. The Effects of Phosphorus and Potassium Application on a 14-year-old Miscanthus × giganteus StandMiscanthus × giganteus (miscanthus) is a perennial C4 grass grown for renewable bioenergy and bioproducts. While miscanthus is often considered to have low nutrient requirements, the need for fertilization remains poorly understood, particularly in mature stands. This study aims to provide insight by evaluating for potential phosphorus (P) and potassium (K) limitations in a 14-year-old miscanthus stand in central Iowa that had received no prior fertilization. The experiment fol... J. Studt, A. Larson, A. Vanloocke, M. Mcdaniel, E. Heaton, N. Boersma |
116. The Future of Soil Fertility - My Two CentsThis presentation will provide information of what a large cooperative is currently providing customers in the realm of nutrient management. Additionally, some insight will be provided on how other aspects of nutrient management (global markets, production technologies, etc) are being evaluated. Finally, some general ideas will be shared regarding the future needs of the retail sector along with some research ideas. ... R. Mullen |
117. The Impact of Shifting from N-based to P-based Manure Management on Corn Silage Yield, Quality, P Balance, and Soil Test PDairy farmers often apply liquid manure to corn (Zea mays L.) for silage to meet N needs (N-based) which results in over-application of P and increased soil test P (STP) levels. A solution to this manure management is switching from N-based to phosphorus (P)-based (P removal based) manure management and supplementing N need with inorganic fertilizer. Intensifying corn for silage rotation with cereal rye (CR; Secale cereale L.) as a forage source could further decrease STP, e... G. Burkett, E. Brevik, S. Babaei, O. Adeyemi, A. Sadeghpour |
118. The Impacts and Magnitude of N Loss from Midwest Cropping Systems: What can we do about it?(Blank Page for Notes) ... |
119. The Manitoba Greenhouse Gas Assessment ToolMethane (CH4) and nitrous oxide (N2O) are potent greenhouse gases (GHGs) emitted by agriculture. Manitoba Agriculture has developed an educational GHG assessment tool that allows farmers to evaluate annual emissions of these GHGs from their practices and explore the impact of changing practices. The first phase of the GHG assessment tool consists of annual estimates of N2O and CH4 emissions from soil and crop management practices, livest... P. Loro, M. Riekman, C. Sawka |
120. The Nitrogen Index as a Tool to Reduce Nitrogen Loss to the EnvironmentContinued population growth creates a need for increased productivity of agricultural systems around the world. Increased agricultural productivity will be needed to support a population that is anticipated to have an additional 2.5 billion people by the year 2050. Nitrogen was part of the 20th century�۪s green revolution. Nitrogen continues to be essential for the viability and sustainability of agricultural systems that are important for feeding the growing global population. It is well kno... |
121. The Use of Organic Soil Amendments for Winter Wheat Production in KentuckyMost animal manures are land-applied in the fall and spring after crops have been harvested or prior to planting. Surface application of manures in the fall have more potential for nitrogen (N) loss when applied to fallow land compared to land cropped to winter wheat. This study was conducted to determine the N availability of fall applied organic fertilizers and resulting wheat grain yields compared to urea-N fertilizer. The effects of three organic fertilizer sources and rate on wheat yield an... |
122. Tillage and Nitrogen Responses to Residue Removal in Continuous CornWith the growing interest in harvesting corn stal k residue for use as biofuel comes the need to examine how residue removal might affect yield a nd N needs of the subsequent corn crop. We are conducted an experiment over the past five years ( 2006 to 2010) at four Illinois locations (three in Mollisols and one in Alfisol) in which all, part, or none of the corn residue is removed, followed by tilled and no-till split within each residue treatment, a nd with N rates split within each residue-til... |
123. Two-sided Banding of Nitrogen and Sulfur Fertilizers Improves Maize Yield and Nutrient Use Efficiency in Midwestern Cropping SystemsEfficient fertilizer management is essential for maximizing crop yield while minimizing environmental impacts. Optimizing fertilizer placement is a key strategy for improving nutrient recovery and synchronizing nutrient availability with crop demand. Traditionally, fertilizer banding in Midwestern maize (Zea mays L.) systems is done on one side of the plant. This study evaluates the impact of two-sided banding of nitrogen (N) and sulfur (S) fertilizers on maize yield and nutrient use... A. Yakubu, A. Ludolph, A. Diop, A. Yakubu, R. Roth |
124. Understanding Wheat Head Counts Effect on YieldWheat (Triticum aestivum) is grown in many parts of the world, with soft red winter wheat (SRWW) being the most popular type grown in Kentucky. Wheat is the fourth most economically important crop in Kentucky and is used in a variety of food products as well as in feed for livestock. Crop scouts reported wheat head counts above the current University of Kentucky threshold for head counts needed to maximize yield. Wheat in other states north reported higher head counts than those obse... A. Mutter, C. Lee |
125. Updating Oat Nitrogen Fertilizer Rate GuidelinesThe current yield-goal based system for calculating oat N rate recommendations in SD has not been evaluated for accuracy recently. There are two main N rate recommendation systems used in the U.S.–Yield goal and maximum return to N (MRTN). Therefore, the objective of this project was to 1) evaluate the accuracy of the current yield goal-based equation and 2) evaluate the accuracy of using the MRTN approach for predicting N rate requirements. Twenty-eight oat N rate response trials were ... J. Clark, D. Karki, A. Bly, P. Sexton |
126. Using Soil and Tissue Testing to Predict Soybean Yield Response to Foliar Applied Micronutrients in IowaPrior research with foliar application of micronutrients for soybean has shown inconsistent yield responses in Iowa and the western Corn Belt. Iowa has no interpretations for soil or tissue tests for micronutrients in soybean. This study's objectives were to evaluate soybean plant-tissue and grain yield responses to foliar application of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in Iowa. There were 22 field trials in 2012 and 21 in 2013, which were established in 20 counties and incl... |
127. Validating Potassium Fertilizer Guidelines in Alfalfa-corn RotationsIn 2008 to 2010, on-farm research was conducted on 10 fields with medium soil test K (STK) to validate Minnesota K fertilizer guidelines by determining the effect of K fertilizer applications on alfalfa yield and quality in its last production year, and estimating the carryover of excess fertilizer K to first-year corn. We were surprised to find that no K fertilizer was needed to maximize alfalfa yield or overall forage feed value and quality. Luxury consumption of K occurred because as K applic... |
128. Variability of Soil Test Potassium in Space and TimePotassium soil test may be highly variable within fields. In the western part of the North Central Region, where the history of K fert ilization is marked by low rates of K fertilizer and fields where K has never been applie d, natural variability of K is governed by clay content and landscape position. In areas where K fertilization has been high, man-made variability is more common. Man-made variability may be experienced as differences in historic rates within fields merged over years of own... |
129. Winter Annual Weeds Affect Nitrogen Availability for No-Till CornWinter annual weeds effects on nitrogen availability have not been adequately studied. The objective of this study was to determine winter annual weed s effects on nitrogen availability for rainfed no -till corn (Zea mays L.) following soybeans ( Glycine max L. Merr.). Field research was conducted in 2010-2011 at 14 sites with heavy winter annual weed pressure in eastern Kansas. A two -factor factorial arrangement in a randomized complete block design with three replications included t hree her... |
130. Winter Wheat Residue Management Affects Corn Grain Yield and Nitrogen RequirementWinter cereal cover crops are effective in reducing the nitrate-N (NO3-N) leaching from corn (Zea mays L.) and soybean (Glycine max L.) fields. An experiment was conducted as a randomized complete block design with split plot arrangement and four replicates to study wheat (Triticum aestivum L.) cover crop management practices on corn grain yield and nitrogen (N) requirement (economic optimum N rate; EONR). The main plots were four cover crop (CC) treatmen... F. Adeyemi, O. Adeyemi, E. Brevik, A. Sadeghpour |