Proceedings
Year
| Filter results136 paper(s) found. |
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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 Direct Approach to Measure Cover Crop Nitrogen Uptake from Dairy Manure Via 15N EnrichmentFall manure applications are a standard practice across Wisconsin, primarily due to manure storage constraints and unpredictable spring field conditions. Unfortunately, manure derived nitrogen (N) is at risk for runoff and leaching into groundwater without an appropriate mechanism for N retention. Fall-planted grass cover crops can serve as N scavengers, reducing losses of manure N to the environment, especially post-silage harvest, however potential tradeoffs between sufficient N uptake and ... T. Judd, M. Ruark, Z. Freedman |
3. A Novel Calcimeter for Soil Carbonate Assessment with Implications for Accurate Soil Test MethodsCalcium carbonate equivalent content is an important soil characteristic, with rammifications for decisions made in agricultural production and soil testing labs alike. However, soil carbonate measurements are rarely included with soil fertility analyses in Kansas due to their tedius nature and the cost of analysis. The objectives of this study were to develop a reliable calcimeter using open-source electronics and readily available labware, and to evaluate it’s performance against proc... B. Rutter, D. Ruiz Diaz |
4. Aerial Photographs to Guide Corn Fertigation DecisionsCorn producers with pivot irrigatio n have the potential to apply in-season nitrogen (N) fertilizer much more easily than their non-irrigated counterpa rts. A demonstration project was initiated in 2006 to take advantage of this potential. One advantage for in-season N application is that the risk of N loss prior to crop uptake is minimal. Another advantage is the opportunity to diagnose N n eed. A range of studies have shown that N need can vary widely from one field to another, as well as with... |
5. An Evaluation of Summer Cover Crops for Agroecosystem Services in Small Grain SystemsCover cropping has been gaining popularity in recent years, specifically for its ability to improve soil properties and suppress weeds. However, cover crop species differ in the agroecosystem services they provide. Our objective was to evaluate a variety of summer cover crop treatments and their ability to provide soil physical protection, increased yield and quality of subsequent small grains, nitrogen input reduction, and weed suppression. Six summer cover treatments were evaluated for thes... S. Watkins, H. Poffenbarger, D. Van Sanford |
6. Assessing Different Sources of Phosphorus Fertilizer on Nitrate Leaching in the Fall Period and Its Effect on the Following CornIllinois nutrient loss reduction strategy is questing to reduce nitrate and phosphorus (P) loss by 25 and 15% by 2025. Fall applied ammonium-based P fertilizers could result in both nitrate and phosphate loss during the fallow period. Two ways to minimize these losses are by utilizing urease and nitrification inhibitors and also assessing other sources of P including triple superphosphate (TSP) and dissolved air flotation (DAF) that separates solids from liquid manure. A four-times replicated... S. Koduru, M. Javid, R. Keshavarz Afshar, A. Margenot, A. Sadeghpour |
7. Assessing Fall Applied Phosphorus Sources and Wheat Cover Crop on the Following Soybean PerformanceGrowers often maintain soil test phosphorus (STP) using ammonium phosphate fertilizers, such as diammonium phosphate (DAP, 18-46-0) or monoammonium phosphate (MAP, 11-52-0) and employ fall application to avoid competition for time and wet field conditions, both prevalent in the spring. However, fall application of nitrogen (N) with these P fertilizers presents a risk of N loss over the fallow period. One source that could minimize N loss during the fallow period is triple superphosphate (TSP;... M. Javid, J. Mcgrath, S. Babaei, F. Sheikhi Shahrivar, A. Sadeghpour |
8. Assessing the Effectiveness of Green-Seeker Algorithm in Minimizing Nitrogen Loss in Corn Production SystemsTo improve water quality, nitrogen (N) management in corn production systems should shift from 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 requirement (EORN) i... O. Guzel, A. Sadeghpour, J. Mcgrath |
9. 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 |
10. 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 |
11. Can CRP Serve As a Soil Health Benchmark: A Minnesota Case Study Utilizing SMAFSoil health is an important concept relating to sustainable agriculture and food security. However, the absence of a universally accepted benchmark for soil health complicates its application as a tool to measure soil functional capabilities. Here we propose the use of Conservation Reserve Program (CRP) soils as a potential benchmark for soil health in Southern Minnesota. The Soil Management Assessment Framework (SMAF) was used to evaluate soil health indicators and quantify the soil health g... O. Hoffman, C. Chorpenning, C. Buchanan, T. Trimarco, N. Carr, J. Ippolito |
12. 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 |
13. Can Multi-Year Fertilizer Applications Improve Productivity in a Corn and Soybean Rotation?Corn (Zea mays L.) yield responses to fertilizer are often greater when the fertilizer is applied in the same year, while soybean [Glycine max (L.) Merr.] yields are typically equivalent or higher when fertilizer was applied in a previous year. Thus, a common fertilization practice in the Midwest is to apply two-crop amounts of P, K, and S fertilizers during the corn phase of a corn-soybean rotation. However, with rising fertilizer costs, it is important to purchase and appl... S. Leskanich, C. Sible, F. Below |
14. 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 |
15. Combined Effects of Nitrogen Rate, Source, and Enhanced Efficiency Fertilizer Use in Indiana Corn ProductionSynthetic nitrogen (N) fertilizer is the most significant fertilizer applied with regards to both quantity, cost, and yield impacts for Midwest corn (Zea mays L.) production. However, with continued risk of nitrate (NO3) leaching causing groundwater contamination, N volatilization, and dentification which increases nitrous oxide (N2O) emissions, continued N management practice improvement, enhanced efficiency N fertilizer use (e.g., nitrification inhibitors, ure... D. Quinn |
16. Corn and Soybean Grain Yield and Concentration of Potassium in Plant Tissues and Soil as Affected by Potassium FertilizationResearch in the Midwest has shown that K fer tilization tends to increase plant K uptake by corn and soybean and the K concentration of vegeta tive tissues. Several studies found that K fertilization usually increases the K concentrati on of vegetative plant parts, often regardless of the soil-test K (STK) level a nd grain yield response (Malla rino et al., 1999; Borges and Mallarino, 2000; Yin and Vyn, 2002a, 2002b; Borg es and Mallarino, 2003; Yin and Vyn, 2003). It is well known that the K co... |
17. Corn Grain Yield and Quality Response to Commercial Biostimulant Products and Nitrification InhibitorsBiological nitrogen (N) fixation by microorganisms plays a crucial role in the N cycle, transforming atmospheric nitrogen (N₂) into ammonia (NH₃) and enhancing plant growth. The objective of this study was to evaluate three biological N fixing products or biostimulants (BS), including Gluconacetobacter diazotrophicus (BS-1), Klebsiella variicola + Kosakonia sacchari (BS-2), and Methylobacterium symbioticum (BS-3) for their in-field performance in enhanc... R. Paul, G. Singh , K. Nelson, G. Kaur |
18. Corn Grain Yield Response to Nitrogen Rate Timing, Source, and Nitrification Inhibitor in MissouriNitrogen response depends on several factors including weather conditions, soil N supply capacity, previous crop in rotation, plant population, and fertilizer management practices. Fertilizer management practices include fertilizer rate, source, application timing, placement, and use of nitrogen stabilizer. In Missouri, the nitrogen fertilizer rate recommendations for corn are based on the yield goal equation. This equation includes the target plant population, pounds of nitrogen removed per ... G. Singh , K. Nelson, G. Kaur , J. Lory, M. Davis, L. Abendroth, H. Naumann, J. Calhoun, J. Chlapecka, W. Bradley, C.J. Ransom, R. Carson, P. Pal |
19. Corn Response to Nitrogen Rate at Three Topographic Positions Within a Terraced LandformNitrogen (N) application and topographic positions (TPs) are critical factors affecting corn (Zea mays L.) grain yield and quality, particularly in regions with diverse terrain like Northern Missouri. A field experiment was conducted in Northern Missouri in 2022 and 2023 to evaluate the effects of four nitrogen rates (0, 120, 200, and 280 N lb acre-1) and three TPs (shoulder, backslope, and footslope) on corn yield and quality. Corn grain yield increased with N application rates th... M. Muhammad Aslam, G. Singh , K. Nelson, G. Kaur |
20. Corn Response to Sulfur Fertilization in Central Iowa SoilsReductions in atmospheric sulfur (S) deposition and increased S removal through continuous cropping have led to S fertilizer responses in many crops. Responses to S fertilization by corn (Zea mays L.), however, have been inconsistent across the upper Midwest. Our objectives with this field study were to: (i) compare S sources for corn vegetative growth and grain yield; (ii) evaluate soil extractable S and S tissue concentrations at different growth stages as S diagnostic too... J. Kovar, C. Crespo, C. Hart, R. Roth, P. O'brien, S. Ruis |
21. County-Level Phosphorus Balances for 2017 in IllinoisCropland phosphorus (P) balances (manure and fertilizer P minus crop P removal) are great sustainability tools to assess long-term managements at farm, county, and state levels. Our objectives were to estimate county, regional, and state-level cropland P balances for Illinois in 2017. Based on the census data in 2017, Illinois county P balance ranged from -14.38 to 36 lb/acre/yr. Overall, Illinois had a negative P balance at about -3 lb/acre/yr. About 71% of counties, had a negative P balance... X. Liu, S. Xu, A. Margenot, A. Sadeghpour, O. Zandvakili, M. Guzel |
22. Cover Crop Composition: Implications for Crop Yields, Nitrogen Use, and Soil Health in Corn-Soybean RotationsCover crops can improve agricultural sustainability by influencing nitrogen (N) use, enhancing soil health, and optimizing crop yields. However, their effects can vary based on species composition. This study evaluated how different cover crop compositions impact crop yields, N requirements, and soil health in corn-soybean rotations. Field experiments were conducted at Brookings and Beresford, South Dakota. Three cover crops (none, single grass, and multi-species) were interse... S. Kodali, J. Clark |
23. Cover Crop Management for Soybean Iron Deficiency ChlorosisIron Deficiency Chlorosis (IDC) has been a s oybean production in the Upper Midwest for many years. A study was conducted in 2006 and 2007 to determine the effect of cover crop management under increasing soil nitrate-N concentrations. The study was conducted at two locations each year with histor ies of IDC. The treatments incl ude nitrogen rates of 0, 100, and 200 pounds N per acre applied as Ur ea with and without an oat cover crop. The oat cover crop was planted at a rate of 1 bushe l per ac... |
24. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern IllinoisIt is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized c... A. Sadeghpour, C. Kula, G. Sener |
25. Cover Crops and Nitrogen Cycling in North Dakota Cropping SystemsCover crops have proven effective in reducing wind and water erosion, improving soil health, and capturing excess N in the fall to prevent leaching. Although the benefits of cover crops to soil health are widely reported, their impact on the yield of the following crops is not clear. The purpose of this North Dakota study was to determine the impact cover crops have on the yield of following corn (Zea Mays L.) and wheat (Triticum aestivum L.) crops along with quantifying nit... B. Goettl, D. Franzen |
26. 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 |
27. Crop and Soil Response to Different Phosphorus Management ApproachesPhosphorus (P) management has implications for crop production and water quality issues in Ohio. Recent data from 457 field P trials conducted in Ohio reported less than 25% positive yield response to P fertilization. It warrants further evaluation of crop P uptake, soil P levels and environmental factors to improve the predictability of crop yield response. Therefore, we collected soil and plant data from three P fertilizer trials (Wooster, South Charleston, and Custar) established in 2006. ... M. Rakkar, L. Fleuridor, S. Culman, G. Labarge |
28. 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 |
29. 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 |
30. 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 |
31. Effect of Barley and Winter Pea Cover Crops on Nitrogen Availability in No-Till CornCover crops are known to have positive effects on soil health and reduce erosion. However, popular cereal grains used as cover crops, such as rye (Secale cereale), wheat (Triticum aestivum), and barley (Hordeum vulgare) can negatively affect nitrogen availability for the subsequent corn crop. Legumes, such as winter peas (Pisum sativum) could reduce competition for nitrogen between the cereal cover crop and the summer corn crop. This study's objective is to determine if barley as a cover ... E. Marsh, C. Lee |
32. 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 |
33. 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 |
34. 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 |
35. Effect of Phosphorus and Potassium Application on the Growth and Yield of a 14 Year Old Miscanthus X Giganteus StandMiscanthus x gigantues (miscanthus) is a perennial C4 grass grown for renewable bioenergy and bioproducts. Despite its known low nutrient requirements, the specific fertilization needs of miscanthus remain poorly constrained, especially for older stands. This study aims to guide nutrient management practices for miscanthus by determining the demand for phosphorus (P) and potassium (K) fertilization and identifying the soil testing values at which these nutrients optimize yields. To address th... A. Larson, E. Heaton, N. Boersma, J. Studt, S. Emran, M. Mcdaniel, A. Vanloocke |
36. 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 |
37. Effects of Cover Crops on Surface Runoff Under Increasing Precipitation IntensitiesWith climate change increasing the frequency of extreme precipitation events, the risks of erosion, nutrient transport and flooding increase as well. Cover crops (CC) are a best management practice for cropping systems that are vulnerable to soil erosion. The objective was to analyze the effects of CC and precipitation intensity on surface runoff and water quality under natural precipitation events. Runoff and water quality data were collected from 2015-2022 from a corn-soybean crop... S. Moylan, N.O. Nelson, G. Kluitenberg, A. Sheshukov |
38. 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 |
39. Effects of Phosphorus Fertilizer Rate, Timing, and Addition of Fertilizer Enhancer on Potato Yield and QualityPotato plants are very inefficient in their abil ity to utilize soil phosphorus (P) on some soils (Kelling et al., 1997). The optimum soil test P category for potato is more than three times greater than for other crops (Laboski et al ., 2006). Being a high value crop, potato growers generally tend to apply more P fertilizer than recommended because it is inexpensive insurance if a yield response to applied P would occur. State nutrient management regulation requires growers to write and follow ... |
40. 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 |
41. 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 |
42. Enhancing Nitrogen Fertilizer Efficiency in Sorghum to Boost Yields and Reduced Nitrogen LossNitrogen management is crucial in modern farming as it plays a major role in achieving higher yields. This study aimed to identify the optimal nitrogen application rate and best management practices to prevent over-application, nitrogen losses, and nitrogen deficiency in crops. Kansas, a leading state in sorghum production, served as the study's setting. Research was conducted at four sites during 2021 and 2022 on rain-fed fields in North-East and North-West Kansas. The objectiv... M. Platero, P. Morinigo Ferreira, D. Ruiz Diaz, P. Tomlinson |
43. 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 |
44. 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 |
45. 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 |
46. 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 |
47. 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 |
48. 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 |
49. Evaluating the Effects of Nitrogen Source, Placement, and Timing on Corn Yield and Nitrogen Losses in the Sandy Soils of Northeast NebraskaThe impact of nitrogen sources, placement, enhanced efficiency fertilizers (EEFs), and application timing on improving groundwater quality in groundwater management areas remains unclear. This study assessed the effects of various N fertilizer sources, EEFs, application timing, and placement on corn yield and nitrogen losses via nitrate (NO3- ) leaching and ammonia (NH3) volatilization. The experiment was conducted in 2023, a notably dry year, at a farmer&rsqu... A. Singh, C. Misar, J. Iqbal |
50. Evaluating the Removal of Corn Residue on Crop Production and Soil QualityRemoval for corn residue as a possible feedstock for the biofuels industry leaves many producers with a number of unanswered questions. These include what impact will this have on the following crop and also the impact on soil quality associated with this practice. A field study was established in 2000 to addr ess these and other questions. Experimental treatments include three corn residue removal levels (low, mid and high); corn harvested for grain and all residue remains on the soil surface,... |
51. Evaluation of Dicyandiamide and Enhanced Efficiency Fertilizers on Corn Production in Upstate MissouriNitrogen fertilizer is the most yield-responsive nutrient in corn production. In-field variability of soil properties such as organic matter content, drainage class, and microbial activity causes challenges in managing this nutrient which causes reduced yield potential and N-use efficiency. Enhanced efficiency fertilizers (EEFs) could reduce some of this variability by keeping N available to the plant longer. This research evaluated a non-treated control (NTC, 0 lbs N ac-1, dicyandiamide (DCD... D. Steinkamp, K. Nelson, G. Singh , M. Davis |
52. Evaluation of the Greenseeker Active Sensor for Sugarbeet Cropping System Nitrogen ManagementThe application of adequate, non-excessive rates of N fertilizer to sugarbeets ( Beta vulgaris L.) continues to increase in importance with rising fertilizer costs and industry transitions from yield-based payments to payments weighted towa rd crop quality. The objective of this study is to evaluate the use of an optical sensor for its potential in assessing in-season sugarbeet N status, in-season yield prediction, and total N in foliage on day of harvest. Six N fertilizer treatments, from 0 to ... |
53. Factors Affecting the Relative Benefit of Deep-banding versus Broadcast Application of Phosphorus and Potassium for Corn and SoybeanScientifically based recommendations concerning the choice of deep banding versus traditional broadcast application of phosphorus (P) and potassium (K) for corn and soybean production in conservation tillage systems have been hampered by insufficient research and inconsistent results. Even when the decisi on is made (e.g. by strip-tillage corn farmers) to go with deep- banding of P and K, numerous questions remain about fertilizer rates, optimum deep-banding depth and frequency, whether to have ... |
54. 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 |
55. 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 |
56. Fertilizer Placement with Seed - A Decision AidBanding fertilizers with the seed at planting con tinues to be a popular option with producers in the Great Plains and North Central regions of the U.S. However, seed-placed fertilizer may limit germination/emergence of the seed/seedling. Nutrie nt source and rate are two factors affecting injury that are relatively simple to manage. Unfortunately, many crop producers and advisors have few rate guidelines for the many crop by fer tilizer combinations that are common to the region. The objectives... |
57. 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 |
58. Field Measurements of Nitrous Oxide Emissions across a Nitrogen Fertilizer Gradient for Corn Cropping SystemsSignificant reductions in nitrous oxide (N 2O) emissions from corn (Zea maize L.) cropping systems may be possible by reducing N fertilizer i nputs with relatively little impact on crop grain yield or economic return. To te st this hypothesis, experiments we re conducted at 4 locations in corn production in Michigan in 2007. All sites were under a corn-soybean rotation. Prior to planting, six rates of urea fertilizer (0-200 lb ac -1) were broadcast and incorporated into four replicate plots (RCB... |
59. Finding the “Sweet” Spot: Nitrogen Strategies for Variable Sugarbeet Harvest TimingsEarly sugarbeet (Beta vulgaris L.) harvest is a new challenge facing the Michigan sugarbeet industry. Due to sugar processing capacity limitations, earlier sugarbeet harvest is necessary to ensure beet processing is complete by mid- to late-March. The early harvest time interval compounds the N application issue as a large percentage of applied N is utilized by the plant later in the growing season. Few data indicate how early or how late N can be applied and the subsequent effects o... K. Steinke, S. Fleming |
60. 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 |
61. 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 |
62. 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 |
63. 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 |
64. Impact of Different Inorganic Phosphorus (P) Fertilizer Rates on Soil P PoolsPhosphorus runoff from agricultural fields is one of the contributors to the contamination and degradation of various aquatic ecosystems. Data from Ohio fertilizer trials show applying phosphorus (P) leads to an accumulation of P in the available pool, but the crop yield response remains unaffected. A better understanding of other P pools would be beneficial for comprehending the yield responses. This study aims to determine the impact of different inorganic P fertilizer rates on soil P pools... J. Singh, J. Ippolito, G. Labarge, M. Rakkar |
65. Impact of Nitrogen Application Timing on Corn Yield and Farm Profitability in Different Wheat Cover Cropping SystemsThe continuous increase in the concentrations of nitrogen (N) and phosphorus (P) in the Upper Mississippi River Basin (UMRB), has led to the introduction of mitigation strategies with the use of winter cereal cover crop such as winter wheat (Triticum aestivum). The understanding of the use of these winter cereal cover crops in relation to soil N and its impact on corn yield is imperative. The study investigates the impact of cover crop termination and N application timing on corn pro... F. Adeyemi, O. Adeyemi, J. Mcgrath, S. Armstrong, A. Sadeghpour |
66. 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 |
67. 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 |
68. Implication of Soil Conservation Practices on Fertility ManagementManagement practices for soil conservation are crucial for reducing soil degradation, and improving crop productivity and soil health. Often these practices are implemented after a problem has already occurred in a field. Therefore, because of changes in conservation management and year-to-year variability soil conditions are often not in a state of balance. Management practices for soil conservation are often studied to establish their impact on crop production, other soil properties, and th... F. Arriaga |
69. 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 |
70. In-Season Nitrogen Management for Corn ProductionWater quality impairment related to nitrogen (N) continues to be a concern in Iowa, including the nitrate drinking water standard, USEPA proposed surface water quality nutrient criteria, and the Gulf of Mexico hypoxia. Addressing these issues could include strict guidance for N input to corn and resultant N use practices that require very high level of management and risk, with unknown economic consequences. Rate of N application is an important ma nagement factor in corn production related to n... |
71. Industrial Hemp Response to Nitrogen ApplicationsWith the increasing interest in industrial hemp (Cannabis sativa L.) as a versatile crop for both fiber and grain production, optimizing nitrogen (N) management has become critical for maximizing its productivity. Field experiments were conducted at two locations (Novelty, Albany) in northern Missouri to evaluate the effects of N application rates on industrial hemp growth, biomass, and grain yield. The experiment was set as a randomized complete block design with a split-plot arran... A. Nain, G. Kaur , K. Nelson, G. Singh , J. Miller |
72. 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 |
73. 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 |
74. 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 |
75. 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 |
76. 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 |
77. 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 |
78. 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 |
79. Investigating the Effects of Tillage Practices and Fertilizer Placement Strategies on Corn Yield and Nutrient Uptake in Eastern South DakotaIn South Dakota, phosphorus (P) and potassium (K) fertilizers are often used to optimize corn (Zea may L.) grain yields and maintain soil fertility. The placement of these fertilizers often has an impact on the nutrient accessibility to the plant and the fertilizer’s impact on the environment. The management of these fertilizers is largely influenced by the tillage system utilized. In the western corn belt, producers have historically used a combination of conventional an... C. Tesch, P. Kovacs |
80. 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 |
81. Is Field Crop Contamination with Heavy Metals an Emerging Concern?Heavy metal contamination of food, particularly food consumed by infants and young children, with arsenic (As), cadmium (Cd), and lead (Pb) is a major food safety concern in the United States and beginning to draw heightened regulatory scrutiny. Crop uptake of heavy metals also has high spatiotemporal variability due to multiple soil, field, climate and plant factors. Management strategies that minimize heavy metal uptake and translocation are needed. The objective of this field study was to ... K. Steinke, Z. Hayden, M. Suplito |
82. Landscape Positions and Nitrification Inhibitors Affect Corn Productivity and Grain Quality on Claypan SoilsMicrotopographic variations in agroecosystems create spatial variability, necessitating site-specific nitrogen (N) management to enhance corn yields and grain quality. Incorporating nitrification inhibitors (NI) into this management strategy can further optimize efficiency by reducing fertilizer application rates, thereby lowering overall input costs for farmers while maintaining yields. A field experiment was conducted on a field with three topographic positions (TP) i.e, shoulder (SH), back... P. Kadari, G. Singh , K. Nelson, G. Kaur |
83. 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 |
84. Long-Term (16-year) Comparison of Phosphorus Fertilization Strategies: Targeted Soil Test Values Vs. Crop Removal in Corn ProductionDeveloping effective phosphorus (P) fertilization strategies to optimize corn (Zea mays L.) yields across varying environmental conditions is essential. This 16-year study, conducted on Nora silt loam soil in Concord, NE (initial Bray-1 P of 16±3 mg kg⁻¹), evaluated different P fertilization strategies under dry, normal, and wet years. The treatments included: no P or N (NPNN), no P (NP), phosphorus applied at crop removal (CRP), and maintaining soil P at 15 (B15), 30 (B30), and... S. Patel, C. Shapiro, J. Iqbal |
85. Management of Enhanced EfficiencyFertilizersPhosphorus generally occurs in soils as the anions H 2PO4- or HPO4-2, depending on the soil pH. These anions readily react with soil cations su ch as calcium, magnesium, iron, and aluminum to produce various phosphate compounds of limited wate r solubility. Crop recovery of applied P fertilizer can be quite low during the season of application. Specialty Fertilizer Products 1 has developed and patented a family of dicarboxylic co-polymers that can be used as a coating on granular or mixed into l... |
86. Management Practices to Minimize Edge-of-Field Phosphorus LossManaging agricultural phosphorus (P) loss at the edge-of-field is critically important to inhibit the development of algal blooms in freshwater bodies. This is particularly important in the Northern Central region which has an abundance of freshwater lakes, agricultural lands, and harmful algal blooms. Edge-of-field monitoring data allows us to take a broad look at how management affects P export from cropland. Looking across a region over several decades also allows us to evaluate the non-ma... L. Pease |
87. Managing Phosphorus and Potassium Soil Test Levels and Effects on Corn Response to Nitrogen with Variable Crop PricesAnnual fertilizer investment for corn-soybean rotation systems represent a significant portion of annual input costs. Variable crop and fertilizer prices raise questions of which macronutrients can be prioritized or cut from fertilization programs. Corn yield response to N fertilization is affected by soil N supply, crop N demand, and interacting factors that affect crop N use, such as phosphorus (P) and potassium (K) supply. The later also influencing soybean yield in the rotation. To invest... J. Jones |
88. Manure Application Technology and Impact on Nitrogen DynamicsA field study was carried out ne ar Elora, Ontario to assess the impact of manure application timing and method on ammonia volatilization a nd nitrogen availability to the crop. A novel method was developed and calibrated for quan tifying ammonia volatilization using passive dosimeter tubes, which promises to provide an economical alternative to other methods. Ammonia loss was negligible from injected manure treatments, and when manure was incorporated immediately it had smaller losses th an wh... |
89. Nitrogen Application Timings in No-Till Dryland Corn Production SystemRight timing of nitrogen application is one of the practices of the 4 R nutrient stewardship. Three independent trials using a randomized complete block with 4 replications were conducted to determine the optimal (1) split rate, (2) proportion and (3) timing for sidedress N application in non-irrigated corn. In trial 1 (13-site years), five N rates were examined: 60, 120, 180, 240, and 300 lb N/A, which were applied at two split-applications. Split-applications included single- and split-appl... N. Adotey, R. Blair, R. Adotey, N. Montgomery |
90. Nitrogen Dynamics and Agronomic-Environmental Impacts of Annual Vs. Perennial Cover Crops in Irrigated Corn-Soybean Systems on Sandy SoilsIrrigated sandy soils can be highly productive yet vulnerable to Nitrogen (N) losses. Kura Clover (Trifolium ambiguum) living mulch offers an alternative mitigation strategy. However, there is limited research aiming to holistically compare the effect of annual vs. perennial cover crops on season-long N dynamics and agronomic-environmental impacts on corn (Zea Mays L.)-soybean [Glycine max (L.) Merr.] cropping systems. This 2-yr study assessed rye (Secale cereale) and Kura... E. Garay Lagos, F. Fernández, J. Grossman , V. Sharma, R. Venterea |
91. 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 |
92. 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 |
93. Nitrogen Fertilizer Efficiency in a Long-term Research TrialIn 1993, a long term crop rotation study (The Living Field Laboratory) was initiated at the W.K. Kellogg Biological Station, Hickory Corners, MI, designed to investigate the benefits of cover crops in various integrated systems compared to a conventional system without cover crops. Today, with the rising cost of production (i.e. energy and fertiliz er) and continued environmental concerns, there are strong incentives for corn pr oducers to accurately assess N requirements and improve fertilizer ... |
94. Nitrogen Rate and Harvesting Time Based on Growing Degree Days Influenced Winter Cereal Rye Morphological Traits, Forage Yield, Quality, and Farm Profit in Poorly Drained AlfisolsWinter cereal rye (Secale cereale L.) (WCR) is often double cropped with maize for silage (Zea mays L.) to increase farm forage supply and profit. Spring nitrogen (N) fertilization to WCR could influence its production and quality at different harvesting times. Therefore, two on-farm trials were conducted in the 2019-2020 and 2020-2021 growing seasons to evaluate the effect of harvesting time (late-March to end-of-April considering the growth stage) and spring N fertilizatio... G. Burkett, K. Vaughn, O. Adeyemi, O. Zandvakili, M. Battaglia, S. Babaei, J. Nair, S. Still, A. Sadeghpour |
95. Nitrogen Recalibration for Wheat in North DakotaThe general formula for determining N fertilizer ra te in North Dakota for about thirty-five years has been N-rate = (2.5 X Yield Potential (or Yield G oal) less credits from previous crops and soil test nitrate-N from a 2-foot soil core composite. Historically high fertilizer N costs and the ability to fertilize within fiel ds rather than whole field N management has resulted in a reexamination of N calibration data, and an effort to expand the modern N calibration database with new field exper... |
96. NUE in Practice: Will N-efficient Corn Hybrids Sell?Efficient use of nitrogen (N) fertilizer is becomi ng increasingly important in corn production due to rising N fertilizer prices and growing concer ns about N contamination of ground and surface waters. Seed companies are also beginning to develop hybrids with N use efficiency (NUE) improved through trait introduction. The introduc tion of such hybrids will bring new questions about the value of higher NUE, and about risk ma nagement associated with decreasing, or not increasing, N use rates as... |
97. 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 |
98. 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 |
99. 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 |
100. Phosphorus Management in the North Central Region: A Brief History, Current Unknowns and Next StepsThe history of phosphorus (P) reflects the history of agriculture in the North Central region. The yield-limiting importance of P, secondary to nitrogen, was recognized as at the turn of the 19th century. An overview of key developments and unfinished business following the picking of these low hanging fruit in the 20th century that face researchers, agronomists, and producers will be discussed. These include assessing P mobility, P sources from fertilizer versus soil, the concept o... A. Margenot |
101. 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 |
102. Plant Population Influences on Maize Physiological Responses to Nitrogen ApplicationPast genetic improvements in maize ( Zea mays L.) have led to the creation of modern hybrids that are increasingly tolerant to a variety of stresses and, in particular, to high plant populations. However, high plant densities can adversely a ffect overall grain yield due to greater intra- specific (within species) competition for lim iting resources. This competition increases barrenness and plant-to-plant variability for grain yield (GY CV) and other morpho-physiological traits. In this study, ... |
103. Polymer Coated Urea and Time of Application for Corn Production in MinnesotaManaging N for corn production is a key to minimizing N losses. Excessively wet spring conditions resulting from ongoing climate change exacerbate loss potential of early spring N applications. Also, a shift in available N fertilizer sources calls for an extensive evaluation of these sources across different soil conditions to update the current N best management practices. The objectives of this research are to evaluate various urea, polymer-coated urea (PCU), and PCU-urea blends and N appli... F. Fernández, K. Fabrizzi, J. Vetsch, W.F. Lazarus |
104. 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 |
105. Predicting Relative Yield of Corn in Indiana Using an Active SensorFine-tuning N fertilization is important for impr oving the economic and environmental impact of corn production. This importance is highlighted by ever rising fertilizer prices and increased public scrutiny. Reflectance measurements usi ng an active sensor during the growing season may be useful for determining the need for additio nal N. This is the second year of a multi-year study to evaluate canopy reflectanc e as an N management tool across a variety of Indiana soil types. The objectives o... |
106. 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 |
107. 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 |
108. Short Term Effect of Double Cropping and Cover Cropping on Soil Physical PropertiesIntegrating cover crops into corn (Zea mays L.)-soybean (Glycine max L.) rotation has been promoted as a sustainable practice to reduce soil erosion, enhance soil health, and improve agricultural sustainability. However, growers are less inclined to include cover crops into their cash crop rotations especially winter cereals such as winter rye (Secale cereale L.) behind corn. One strategy to minimize the fallow period in corn-soybean rotation is by intensifying the ... F. Sheikhi Shahrivar, O. Ola, O. Guzel, K. Gage, K. Williard, J. Schoonover, S. Mueller, A. Sadeghpour |
109. Short-Stature and Full-Stature Corn Hybrid Response to Nitrogen Rate and Plant PopulationThe recent introduction of short-stature corn (Zea mays L.) hybrids (5-7 ft height) suggests agronomic management recommendations need to be reassessed and updated in comparison to modern full-stature hybrids. Short-stature hybrids target to increase overall Midwest corn production and agronomic efficiency by reducing lodging potential under higher plant populations through improved wind tolerance, stalk strength, and plant standability. However, the optimal combination of nitrogen r... E. Oliva, S. Casteel, D. Quinn |
110. Skip-Row Configuration and Plant Density Effects on Sorghum Grain Yield and Yield Component in Southern NebraskaEqual spacing of sorghum rows typically results in the highest grain yield when soil water is adequate throughout the season, but skip-row plan ting may be a means to reduce water deficits during reproductive growth stages. We evaluated the effect of skip-row planting configuration and plant population density on grain yield, yield components and water use efficiency at five locations in a transect across southern Nebras ka where annual mean precipitation ranges from 300 to 900 mm yr -1. Three r... |
111. 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 |
112. Soil pH and Manganese Effects on Roundup Ready SoybeansSoybean 'flas'h is a general yellowing of th e upper soybean canopy thought to be associated with high rates of glyphosate and reduced levels of manganese (Mn) with glyphosate-resistant soybeans. Several field sites varying in soil Mn levels and some with within field variable pH levels were evaluated between 2004 and 2006 for re sponsiveness of soybeans to glyphosate rate and Mn treatments. The objectives of this study were to 1) evaluate the effects of foliar applied Mn and soil applied Mn on ... |
113. Soybean Response to Phosphorus Fertilizer and Cover Crop Combination in KansasPhosphorus (P) plays a critical role in supporting plant growth and maximizing crop yields, but its availability is often limited in agricultural soils. Cover crops (CC), widely used to improve soil health, can also influence nutrient availability and moisture dynamics. This study investigates the effects of P fertilization and CC on soybean P uptake, soil moisture, and grain yield in Kansas. Field trials were conducted across multiple sites in 2022 and 2023, using a randomized complete block... J. Demarco, D. Ruiz Diaz |
114. 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 |
115. 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 |
116. Sustainable Vegetable Crop Production Using Vermi-CompostThis research intends to utili ze earthworm castings as an alternate nutrient source, especially nitrogen, for vegetable crop production. The experiment was conducted in the greenhouse and 'Mountain Fresh' tomato ( Lycopersicon esculentum Mill.) was used as the test crop. The main objectives were (1) to identify the optimum app lication rate of earthworm castings (EC) for tomato growth, and (2) to compare tomato res ponse under different treatments. Three different textural soils, namely sandy s... |
117. Swine Manure Applications for Soybean Production - Environnmental and Pathological ImplicationsSoybeans are leguminous plant sp ecies capable of fixing nitrogen (N) from the atmosphere to support their growth and development. Despite th e fact that soybeans can fix their own N, in a soil environment rich in inorgani c N they will scavenge for available N decreasing the level of root nodulation (Schmidt et al., 2000; Hester man and Isleib, 1991). Studies conducted to measure the impact of N fertilization of soybean s reveals that crop response to commercial N fertilizer does not result in ... |
118. 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 |
119. 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 |
120. The Effect of Nitrogen Management in Winter Wheat on Nitrous Oxide Emissions in a Wheat-Soybean Double Cropping SystemNitrogen fertilizer management plays a critical role in nitrous oxide (N₂O) emissions in agricultural production systems. This study investigated the impact of nitrogen application in a winter wheat (Triticum aestivum L.)-soybean (Glycine max L.) double cropping system on winter wheat biomass production, grain yield, and N₂O emissions. The experiment was conducted at the Agronomy Research Center (ARC), Carbondale in Southern Illinois University, IL using a Randomized Com... O. Ola, O. Guzel, K. Gage, K. Williard, J. Schoonover, S. Mueller, A. Sadeghpour |
121. 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 |
122. 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 |
123. 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 |
124. The Iowa Nitrogen InitiativeThe Iowa Nitrogen Initiative is a private-public partnership with a vision to provide Iowans with the best nitrogen science for the benefit of productivity, profitability, and environmental performance. We are working alongside agricultural service providers, farmers, and their advisors to design, execute, and interpret hundreds of coordinated on-farm, scientifically robust nitrogen rate trials every year. In 2024, we conducted more than 400 scientifically robust, fully replicated trials. Dat... S. Archontoulis, M. Castellano, M. Miller, M. Baum, R. Osman |
125. 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 |
126. The Three-Legged Stool: Nitrogen, Environment, and Crop ProductionNitrogen, crop production, and environment are interrelated. The presentation will discuss recent and ongoing studies in Minnesota aimed at understanding how to manage nitrogen efficiently to enhance corn production while minimizing negative environmental impact. Realizing that overemphasizing one component or underemphasis another creates instability, just like adding or cutting a piece of a leg in a three-legged stool, this research is trying to find the "sweet spot" where each of... F. Fernández |
127. Tillage, Cereal Rye Cover Crop, and N Placement Effects on Corn and SoybeanAlthough conservation tillage and cover crops can improve soil health, producers are hesitant to adopt these practices due to concerns about potential yield reductions. We conducted field experiments for four years (2020-2023) near Urbana, Illinois, to explore how these practices affected corn and soybean yields. The experiment was conducted on a Flanagan silt loam soil, with corn and soybean following one another on two sides of the same field. Treatments were arranged in a RCBD with four re... F. Rolle, G. Preza Fontes, D. Schaefer, E. Nafziger |
128. Triple-Stacks, Genetics, and Biotechnology in Improving Nitrogen Use of CornGenetic improvement in N use efficiency (NUE) is a clear strategy fo r enhancing yield and fertilizer N management of corn ( Zea mays L.), and has been the subj ect of our ongoing research. Calculation of the N requirement (N fertilizer usage/grain yield) based on statewide average grain yields and fertilizer sales shows a stead y decrease since the mid 1980's, suggestive of a genetic improvement in N use. Direct comparis on of the response to N for a 1980�۪s hybrid with its modern counterpar... |
129. 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 |
130. 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 |
131. Updating Nitrogen, Phosphate and Potash Rate Recommendations (AGR-1) for Kentucky Grain GrowersFor UK soil test lab users, soil test phosphorus (P) and potassium (K) have been slowly declining for several decades, suggesting recommended ‘maintenance’ rates (initiated in 1992) were insufficient. Adjusting for modern grain P and K concentrations and increasing yield-driven nutrient removal, we raised corn, soybean and wheat maintenance rates by 10 to 20 lb P2O5 and 10 to 30 lb K2O per acre, depending on the individual crop. Corn nitrogen (N) rate recommendations had not ... J. Grove, E. Ritchey |
132. 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 |
133. Using Reflectance Sensors to Predict Nitrogen Needs of CottonObjectives 1) Develop on-the-go N recommendations based on analysis of the reflectance sensor readings. 2) Determine the sensor model, height, and wa velength that give the best prediction for sidedress N. 3) Determine the best growth stag e for sensor-based sidedressing Relevance There is great spatial variability of N in the soil. Cotton fields that receive a blanket rate of nitrogen, ignoring the vari ability, will have areas of excessi ve growth. This unnecessary growth raises production cos... |
134. Value of Tillage Practices and Nitrogen Rates for Corn ProductionMost N recommendations for corn (Zea mays L.) production in the U.S. Midwest do not consider tillage as a factor when an appropriate N rate is determined. Our objectives were to determine the response of grain yield and RTN to increasing rates of fertilizer N for corn grown in three tillage systems. Tillage by N rate experiments we re conducted at eight Central Illinois site-years at three locations and years (1998-2000). Tillag e systems employed were: zero-till, where no tillage was performed ... |
135. 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 |
136. Wisconsin's Nitrogen Optimization Pilot Program: Highlights and Successes of On-Farm ResearchAccurately determining nitrogen fertilizer requirements for crops is challenging due to the wide variability introduced by management practices and environmental conditions. Over-application reduces profits and negatively affects 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 nitrogen rates on a field by field basis. In 2023, Wisconsin’s Department of Agric... M. Schauer, M. Ruark |