Proceedings
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| Filter results9 paper(s) found. |
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1. Topsoil Thickness Effects on Phosphorus and Potassium Dynamics on Claypan SoilsDue to variable depth to claypan (DTC) across landscapes, nutrient supply from subsoils, and crop removal, precise P and K fertilizer management on claypan soil fields can be difficult. Therefore, a study was performed to determine if DTC derived from soil apparent electrical conductivity (ECa) could be used to improve P and K management for corn (Zea mays L.) and soybean (Glycine max [L.]). Research was conducted on a claypan soil at the University of Missouri’s... L. Conway, M. Yost, N. Kitchen, N. Kitchen, K. Sudduth |
2. Nitrogen in the Mississippi River Basin- Sources and Factors Affecting Loss of Nitrate to the RiverNitrogen (N) is a naturally occurring element that is essential to plant growth and crop production. In a soil system, nitrate-N is continually supplied through mineralization of soil organic matter. Other sources of N include fertilizers, animal manures, municipal sewage wastes, agricultural and industrial wastes, atmospheric deposition. and dinitrogen fixation, all of which either occur as nitrate-N or can be converted to nitrate-N through mineralization and nitrification. ... |
3. Site-Specific Manure Application Effects on Corn Yield and N StatusManure, a renewable resource, is an excellent source of nutrients that can be substituted for synthetic types of fertilizers. The organic matter in manure can enhance the physical and chemical properties of soils, especially infertile soils, as these soils typically contain low levels of organic matter and nutrients, and have low water holding capacities. The objective of this study was to evaluate the ability of manure application for improving crop yield and N status in less productive areas within... |
4. A Crop-Based Approach for In-Season N Management of CornOver-application of nitrogen (N) fertilizer on corn has resulted in elevated levels of N in ground and surface waters. A major factor contributing to decreased N use efficiency and environmental contamination for traditional corn N management schemes is routine pre-season application of large doses of N before the crop can effectively utilize this N. Our long-term research goal is to reduce these over-applications by using remote sensing to direct fertilizer only to areas needing N at times when... |
5. Relationship Between Response Indices Measured In-Season and at Harvest in Winter WheatCurrent methods for making nitrogen recommendations in winter wheat (Triticum aestivurn L.) do not adjust for in-season temporal variability of plant available non-fertilizer nitrogen (N) sources. The purpose of this study was to compare the use of different nitrogen response indices determined in-season @INDVI and RIPLANTHEIGkm) to the nitrogen response index measured at harvest (RIHARvEST). In addition, this study evaluated the use of the in-season response indices for determining topdress nitrogen... |
6. 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 |
7. Evaluation of soybean response to in-season potassium fertilizationIn-season application of potassium (K) fertilizer may offer an alternative to remediate deficiencies developed during the growing season. The objective of this study was to determine soybean (Glycine max) response to topdress K application timing under deficient soil conditions. Treatments included a control (0 lbs K2O acre-1), 50 lbs K2O acre-1 pre-plant incorporated, and 50 lbs K2O acre-1 in-season broadcasted at the... D.A. Charbonnier, D.A. Ruiz Diaz, M.A. Coelho |
8. 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 |
9. 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 |