Proceedings
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1. Site-Specific Nitrogen Management for Reducing Soil Residual NitrateSite-specific N management has potential for increasing the efficiency of N fertilizer use, and thereby reducing environmental impact. Field studies were conducted in 2000 and 2001 to evaluate the potential for site-specific N management to reduce residual soil nitrate in Missouri cornfields. Field-size side-by-side fertilizer N treatment strips were applied in cooperating farmers' fields. The site-specific crop N requirement (optimal N rate) was determined for sub- blocks that contained a full... |
2. Starter Fertilizer for Row Crop Production Under No-till Conditions in Eastern NebraskaStarter fertilizer application often results in increased corn and sorghum yield under no-till conditions, probably due to lower soil temperatures as compared to tilled soil. Five dryland and 5 irrigated corn trials. and 12 dryland grain sorghum trials were established after soybean in 2002 and 2003 on rolling land in eastern Nebraska with different soil types and topographic positions. Three placement positions were compared: in the seed furrow. over the row. and 2" to the side and 2" deep (2x2).... |
3. The Influence of Nitrogen Rate and Foliar Fetilization on Yield and Nitrosamine Levels in Burley TobaccoMany burley tobacco (Nicotiana tabactm~ L.) producers believe that additions of nitrogen (N) rates greater than those recommended by university extension senices will result in increased yield and income. In addition to high rates of N, many producers feel that additional foliar fertilizer will further increase yield and quality of burley tobacco and result in greater revenue. Concerns with excessive N additions include improper curing, elevated levels of tobacco specific nitrosamines (TSNA's), undesirable... |
4. Understanding Components To High Yielding Soybean Production SystemsThe increasing amount of products and techniques available to producers, coupled with increasing input costs, lends greater importance to the evaluation of management options for optimization of yield and economic return. This study was conducted to determine: 1) soybean yield potential when five additional inputs are combined in a high-intensity production system; 2) soybean yield impact of each additional input when removed from the high-intensity system; 3) soybean yield potential of each additional... |
5. Sulfur Fertility for Kentucky AgricultureSulfur (S) fertility concerns are becoming more common in Kentucky due to the reduction in atmospheric deposition resulting from more stringent air quality concerns. The most likely crops where S deficiency would first occur are winter wheat and alfalfa, due to mineralization rates or high removal rates. Currently few, if any, fields in Kentucky show consistent S deficiency problems. Tissue surveys were conducted in alfalfa fields during 2013 and 2014 to assess S status in alfalfa. Twenty-one percent... |
6. Survey of the Tissue Nutrient Status of Winter Wheat in KentuckyA field survey conducted in western Kentucky (KY) was initiated to determine if University of Kentucky soil fertility recommen dations for winter wheat production was adequate. Twenty- nine fields in 15 western KY counties were iden tified by county extension agents for sampling. Soil and tissue samples were collected for anal ysis in a 150 foot by 150 foot sampling area. Approximately 100 flag leaf samp les were collected, air-dried, ground, and analyzed for N, P, K, Mg, Ca, S, B, Zn, Mn, Fe, and... |
7. One-Time Tillage of No-Till Crop Land: Five Years Post-TillageField research was conducted at two eastern Nebr aska locations to test the hypotheses that one- time tillage of no till (NT) land results in increased grain yield, reduced stratification of available soil phosphorus but reduced wet aggregate stabili ty, and increased soil organic carbon (SOC), without a long term effect on the soil microbial community. Research was conducted in long- term NT fields under rainfed corn [ Zea mays (L.)] or sorghum [Sorghum bicolor (L.) Moench.] rotated with soybeans... |
8. Evaluation of Sulfur Fertilizers In Corn ProductionSulfur deficiencies and corn yield increases from S fertilization have been documented in Iowa since the mid-2000’s. Therefore, S fertilization management is an important component of high yield corn production. Many S fertilizers are available for use in correcting deficiencies. However, specific product evaluations have not been widely conducted in Iowa. In addition, a new S fertilizer has recently become available in the Midwest U.S., the mineral polyhalite. The research objectives were... J. Sawyer, M. Castellano, A. Sassman, J. Lundvall |
9. Manure and Fertilizer Management Influence on Soil Nutrient Levels and Grain Yields in Eastern South Dakota from 2003 to 2014Concentrated animal feeding operations (CAFOs) are required to hold a manure management permit in South Dakota. The permit encompasses available nutrients from manure, crop nutrient use and removal, soil test nitrate-N, and phosphorus and land availability for approved nutrient application rates. The management plan determines if nitrogen or phosphorus based manure application rates are used. Most CAFO’s start out following the nitrogen based plan as soil test phosphorus (P) levels... A. Bly, S. Berg, R. Gelderman, B. Rops, P. Sexton, C. Morris |
10. Post-Harvest Soil Nitrate Following Corn Production in Eight Midwestern StatesApplying nitrogen (N) at economically optimal rates (EONR) and at times of rapid crop uptake are practices that are thought to minimize the amount of residual soil nitrate (RSN) in the profile that may be susceptible to loss. The objective of this study was to evaluate the effects of rate (0 to 280 lb N/a in 40 lb increments) and timing (pre-plant (PP) or PP plus V9 sidedress (PP+SD)) of N application on corn grain yield and RSN in the top 3 feet of soil relative to the calculated EONR. Thirty-two... C. Bandura, C. Laboski, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, E. Nafziger, J. Sawyer, J. Shanahan |
11. Can Unmanned Aerial System-Mounted Passive Sensors Be Used To Recommend Sidedress Nitrogen Rates In Corn? A Comparison Between Active and Passive SensorsThe objectives of this research were to (i) assess the correlation between active and passive crop canopy sensors’ vegetation indices at different corn growth stages, (ii) assess sidedress variable rate nitrogen (N) recommendation accuracy of active and passive sensors compared to the agronomic optimum N rate (AONR) and (iii) assess sidedress VR N rate recommendation correlation between active and passive sensors. Two experiments were conducted, one near Central City, Nebraska on a Novina... L. Bastos, R. Ferguson |
12. Variation in Internal N Efficiency of Corn and Impact on Yield-Goal Based N RecommendationsInternal N efficiency (IE) is defined as bushels per acre (GY) produced per pound of N per acre (PMN) in the plant at physiological maturity (R6). Internal N efficiency defines the required amount of plant N content at R6 in a yield-goal based N rate recommendations (currently used in 30 U.S. states) and several commercial N recommendation models. Commonly IE is assumed to be constant at an approximate value of 0.8 bu lb-N-1 in yield-goal based recommendations. Our research objective was... M. Shafer, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, R. Nielsen, J. Sawyer, J. Shanahan |
13. Nitrogen Use Efficiency and Corn Yield as Affected by Applied Sulfur and Nitrogen FertilizerOverall corn (Zea mays L.) yield response, as well as nitrogen uptake and nitrogen use efficiency, can be affected by multiple factors, including the supply of other nutrients such as sulfur. The objective of this study was to evaluate the effect of nitrogen with added sulfur fertilizer on corn response parameters i) whole plant nitrogen uptake, ii) yield, and iii) nitrogen use efficiency when compared to nitrogen alone. Nitrogen Use Efficiencies evaluated in this study included i) Apparent... T. Husa, D. Ruiz diaz |
14. Revamping Nitrogen Fertilizer Recommendations for MissouriMultiple nitrogen fertilizer rate decision tools have been developed over the years for recommending nitrogen to growers. These tools are based on mass balance equations with expected yield and yield goal, economically optimum nitrogen rate, preplant soil nitrate test, pre-sidedress and late spring soil nitrate test, plant tissue nitrogen, crop growth models, and canopy reflectance sensing. These tools rarely include biological nitrogen in the rate recommendations. Advances in soil health assessment... G. Singh , J.A. Lory, K.A. Nelson, M. Davis, L. Abendroth, G. Kaur, J. Calhoun, J. Chlapecka |
15. 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 tools;... J. Kovar, C. Crespo, C. Hart, R. Roth, P. O'brien, S. Ruis |
16. 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 thousand... 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 |