Proceedings
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| Filter results10 paper(s) found. |
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1. Spatial Variability of Soil Test Phosphorus, Potassium, pH and Organic Matter ContentAs part of a larger study investigating the potential for variable fertilizer N application in corn production, 18 field sites were established on farms across Ontario intensively sampled in the 1995 and 1996 field seasons to assess the spatial variability of soil test P, K, pH and organic matter content. Soil parameters typically display a log-normal distribution (positive skew) which would generally result in the under-fertilization of a greater area of a field if the rate of fertilization was... |
2. Field Scale Variability of Corn Yield response Functions to Fertilizer Nitrogen ApplicationVariable rate nitrogen (N) application assumes that corn response to N fertilizer varies within a field. However, this hypothesis has not been formally tested yet. Field variation of corn response to N fertilizer and economically optimum N fertilizer rates (EON) were assessed in on- farm experiments throughout central Illinois. Fields (16 to 32 ha.) were subdivided into 13 to 20 areas. Five nitrogen rates were randomized within these areas in 28 kg N increments (2 rates) and decrements (2 rates)... |
3. Variable Fertilizer Nitrogen Application Based on the Delta Yield Index- A Field StudyA quick review of the both the scientific and popular literature indicates that many different approaches have been suggested for the prediction of variable fertilizer N applications in the field. In previous meetings of this conference we have presented the general outline and approach taken for our site-specific crop management project in Ontario. Briefly, historical data sets of grain corn response trials to fertilizer N (encompassing some 300 site-years worth of data) indicated that most yield... |
4. Can Nitrapyrin and Cover Crop Improve Fall Dairy Slurry N Availability to Corn?Fall applications of manure have the potential for high nitrogen (N) losses. Cereal/grass cover crops have been shown to take up fall applied N. Similarly, using nitrapyrin (Instinct®) has been shown to prevent loss of fall applied N. No studies have been conducted to evaluate combining these tools to prevent N loss. This experiment was performed in 2016 and 2017 on a well-drained and somewhat poorly drained silt loam soils. This study was conducted to determine if using Instinct® and... A. Teeter, T. Andraski, C. Laboski |
5. No-till corn nitrogen recommendation using precision soil management practicesIn long-term no-till fields, South Dakota (SD) farmers reported a reduced fertilizer-nitrogen (N) requirement compared to conventional tillage to obtain optimum corn yield. Reduced fertilizer recommendation may be due to improved soil health resulting from increasing soil organic matter, higher soil microbial activities, and improved water and nutrient use efficiency over the years the no-till system is used. However, the impact of soil health measurements on fertilizer-N requirement has not been... D. Bhattarai, J. Clark, D. Clay |
6. Implications of Clay Mineral Analysis for Improved Calibration of Corn Potassium Fertilizer RecommendationsEastern South Dakota has seen an increase in soil potassium (K) deficiencies. To correct those deficiencies and avoid yield reductions, corn producers rely on accurate K fertilizer recommendations (KFRs). Among the various parameters used to estimate a KFR, clay mineralogy has significant potential to increase KFR accuracy. The study has two objectives: first, to determine the relationships among clay mineralogy, K uptake by corn, and KFRs, and second, to calibrate KFRs in South Dakota to incorporate... A. Ahlersmeyer, J. Clark, D. Clay, K. Osterloh |
7. Does Interseeded Cover Crops Composition Affect Corn N Fertilizer Needs and Corn and Soybean Yields?Cover crops are often recommended as a valuable practice to develop more sustainable cropping systems. However, interseeding cover crops may change the amount and timing of nitrogen (N) provided to the crop from decomposition (mineralization), which may increase or decrease the N fertilizer required to optimize corn grain yield. This study aims at understanding the effect of cover crop composition (single and multispecies) on soil biological measurements, corn N requirements, and corn and soybean... S. Kodali, J.D. Clark |
8. Consideration of Clay Mineralogy for Enhanced Prediction of Optimal Corn Potassium Fertilizer RatesProperly calibrated potassium (K) fertilizer recommendations (KFRs) are critical for improving crop yields and maintaining environmental stewardship. Recent innovations in soil and crop management suggest that certain soil factors, including clay mineralogy, can be used to predict optimal K requirements in corn. The objectives of this study include 1) correlate soil K levels to corn yield, 2) calibrate KFRs with clay mineralogy data, and 3) determine the relationships among clay mineralogy, K... A. Ahlersmeyer, J. Clark, K. Osterloh, D. Clay |
9. Impact of Cover Crop Composition on Nitrogen Application Rates and the Subsequent Yields of Corn and SoybeanInterseeding cover crops presents a promising strategy for enhancing the sustainability of agricultural systems. Nevertheless, the practice of interseeding cover crops introduces a dynamic element to nitrogen (N) cycling, potentially altering both the quantity and timing of N release through decomposition (mineralization). This variability in N availability may, in turn, influence the optimal nitrogen fertilizer requirements to maximize corn grain yield. However, long-term studies are essential... J.D. Clark , P. Kovacs, P. Sexton, S. Osborne, S. Kodali |
10. 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. Data... S. Archontoulis, M. Castellano, M. Miller, M. Baum, R. Osman |