Proceedings
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1. The Anaerobic Potentially Mineralizable Nitrogen Test as a Tool for Nitrogen Management in the MidwestThe anaerobic potentially mineralizable nitrogen (PMNan) test is a tool that can improve estimations of mineralizable nitrogen (N) and enhance nitrogen use efficiency. This tool may also help improve predictions of N uptake, grain yield, and the economic optimum nitrogen rate (EONR) of corn (Zea mays L.). A 32 site-year study across eight US Midwestern states was conducted to 1) compare the effect of incubation length (7-, 14-, 28-d), soil sampling timing, N fertilizer rate, and their... J. Clark, K. Sloan veum, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan |
2. Nitrogen Fertilizer on Soybeans: Are We Making Progress?The recent drop in the price of soybeans has dampened enthusiasm for applying inputs of uncertain value to crops, but application of fertilizer N during the season is often reported by soybean yield contest winners as a way to increase yields, and some producers have adopted this as a practice. As soybean yields have increased, the amount of N required by the crop has increased. Soybean seed with 36 percent protein is about 5.75% N, and a bushel of soybean grain contains about 3 lb.... E. Nafziger, J. Vonk |
3. Measuring Soil Quality Changes in Corn and Soybean RotationsSoil quality is described as the ability of the soil to sustain crop growth and development along with nutrient cycling and water infiltration and retention. One possible strategy to maintain or increase soil quality is crop rotation. Crop rotations have the potential to increase crop yields, disrupt diseaseand pest cycles, and when a legume is added to the rotation, reduce nitrogen fertilizer requirements. Although the long-term productivity and sustainability of agriculture are dependent on maintaining... M. Adams, G. Behke, E. Nafziger, M. Villamil |
4. Are We Getting Better at Supplying Corn with Nitrogen?While the MRTN approach to making N rate guidelines is an improvement over previous methods, there remains the question about whether or not the database is sufficiently large to support the results adequately. This question is brought into focus when N rates used according to the MRTN guidelines are seen (or at least perceived) as being be inadequate in a given field or area in a given year. Other entities now making N rate recommendations may also market against the MRTN approach by raising doubts... |
5. Which Corn Nitrogen Fertilization Rate Tools Preforms the Best in the Midwest?Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. Performance of a tool is often based on the specific soil and weather conditions of a growing season. Research is needed to determine which tools are the most effective at recommending economical optimal N... |
6. Effect of Three Tillage Systems on Soil Bulk Density and Porespace DistributionMany grain producers in Kentucky use a 3 crop in 2 year rotation of corn fol lowed by small grain-soybeans, and commonly no-ti1 1 the soybeans and corn in order to intensively use sloping land for continuous grain production. Because of the intensity of machinery traffic in this system, grtwxs. are concerned that continuw no-till management may cause compaction, and that such fields may need occasional primary tillage. In order to obtain information regarding this situation, we conducted a test for... |
7. Studies of Agricultural Effects on Groundwater Quality in KentuckySeveral small watersheds and tiled fields have been selected in Kentucky to assess the influence of agricultural practices on groundwater quality. Sites were selected to represent the dominant agricultural systems used in the most agriculturally important areas of the state. Within each study site, water samples from springs, wells, streams, or tile lines are being sampled monthly to monitor content of N03-N, atrazine. alachlor, and fecal bacteria. Although sampling will continue for at least another... |
8. Use of A Wheat Cover Crop to Trap Residual Soil N for No-till CornIn continued work on long-term no-till plots, wheat was tested as a winter cover crop to determine how much carryover soil N it would accumulate from the preceding no-till corn crop and make available to the successive no-till corn crop. Wheat biomass at time of planting no-till corn was about 1.7 times greater following 240 lbs N/A on the preceding corn than following 80 lbs N/A. However, maximum wheat biomass was only about 1 T/A, and contained only 15 lbs N/A more than wheat grown following corn... |
9. Using High-Tech Media Tools to Transfer the Principals of System Research to FarmersBeginning in 1981, research and extension personnel at Virginia Tech and the University of Maryland formed Intensive Wheat Management Teams. Over the next six years these Teams developed a higher yielding, more profitable and environmentally superior soft red winter wheat production system. Yields greater than 100 bu/a were achieved every year. This was at a time when average wheat yields were in the 40 bu/a range (Table 1). Intensive wheat research continues today to refine and update the system.... |
10. A Field Study of Soil Test Variability, Its Effects on Accuracy of Fertilizer Recommendations, and the Subsequent Effect of Variable Rate Fertilizer Application on Soil Test ValuesThree 2.5 acre blocks were selected for intensive soil sampling from within an approximate 90 acre field which had been partitioned into 35, 2.5 acre blocks by a farm supply dealer. The 2.5 acre blocks had previously been sampled on a central composite grid basis and a variable rate fertilizer spreader (VRS) programmed for fertilizing the field. Three other more intensive sampling techniques were used to sample the 3 blocks selected for more detailed studies. Results obtained showed that soil test... |
11. Evaluation of Novel Soybean Inputs to Enhance YieldThe U.S. Average soybean yield was 43.5 bushes/acre in 2010 (www.nass.usda.gov), with reports of much higher yields in some areas. With large yield differences among years and locations, as well as some high-profile marketing and publicity campaigns promoting 'high yield' management, producers are interested in any inputs or management practices that might improve yields. High soybean prices at present and interest in finding ways to increase yield have led to emergence of a number of new products,... |
12. Hybrid and Plant Density Effects on Nitrogen Response In CornThe development of corn hybrids that may be improved for nitrogen use efficiency along with the emphasis on higher plant density for maximum yields of modern hybrids have raised questions about interactions between N rate and plant density. We planted four hybrids (Pioneer 33D49, 33K44, 33W84, and 34F07) to represent a range of responses to N rate and plant density at four sites in Illinois at combinations of densities of 44,460, 83,980, and 123,500 plants ha -1 and N rates of 0, 90, 179, and 269... |
13. Active-Optical Reflectance Sensing Evaluated for Red and Red-Edge Waveband SensitivityUncertainty exists with corn (Zea mays L.) N management due to year-to-year variation in crop N need, soil N supply, and N loss from leaching, volatilization, and denitrification. Active-optical reflectance sensing (AORS) has proven effective in some fields for generating N fertilizer recommendations that improve N use efficiency. However, various sensors utilize different wavebands of light to calculate N fertilizer recommendations making it difficult to know which waveband is most sensitive... G. Bean, N. Kitchen, J. Camberato, R. Ferguson, F. Fernandez, D. Franzen, C. Laboski, E. Nafziger, J. Sawyer, P. Scharf, J. Schepers, J. Shanahan |
14. Do Split-Nitrogen Applications in the Midwest Affect Corn Nitrogen Uptake and Grain Yield?It is hypothesized that split-nitrogen (N) relative to single near-planting applications improve corn (Zea mays L.) grain yield and nitrogen recovery efficiency, which can lessen environmental impacts of fertilization. However, these hypotheses have not been fully tested. A 49-site-year study across eight US Midwestern states over three years was conducted to compare near-planting (Single) and split-N (Split) applications. Three N application timings were evaluated [Single near planting, 40... J. Clark, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan |
15. Late-Split Nitrogen Application On CornThe practice of applying a last (or additional) increment of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We established a set of trials in which a range of N rates from 0 to 280 kg/ ha were applied as UAN solution, either all at planting or with 56 kg N reserved and hand-applied at the base of the plants at tasseling (late-split... D. Rapp, E. Nafziger |
16. Nitrogen Fertilizer For SoybeanConcern about soybean’s ability to provide energy to fix adequate N while still producing high yields has led to renewed interest in in-season use of N fertilizer. We conducted a series of fertilizer N timing experiments in Illinois, in different soil types with a range of yield potential. There were few responses to N in silt loam soils, with unfertilized check yields ranging from 4,108 to 6,125 kg/ha, though applying the same N increment four times increased yield significantly... J. Vonk, E. Nafziger |
17. Does it Pay to Sidedress Some of the Nitrogen on Corn?Dividing the amount of nitrogen fertilizer applied to corn over two or three applications has become a common practice, based on the understanding that waiting to apply some of the N lowers the potential for loss of N, and that applying N during vegetative growth stages enables N to get into the plant quickly when the plant is rapidly taking up N. Across 20 sites, spring preplant ammonia at 200 lb. N/acre, fall-applied ammonia at 100 lb. N/acre + 50 lb. N as UAN injected at planting + 50... E. Nafziger |
18. Fertilizer Manufacture - Converting Nature's Nutrient Storehouse to Plant NutritionNorth American farmers rely on reliable supply of key fertilizer inputs to maintain productivity and profitability. Nitrogen fertilizers are produced from atmospheric nitrogen gas, while phosphate and potash fertilizers are mined from major North American deposits as well as others around the world. All the major fertilizers are supplied, in large part, by North American producers from domestic production supplemented by some imports from international producers. Nitrogen production... A. Blaylock |
19. The Ammonia RainbowAgriculture has been identified as a major contributor to atmospheric carbon dioxide with nitrogen fertilizer production as a key component. Recent scrutiny of nitrogen production processes has identified ammonia production processes to reduce carbon output from traditional Haber-Bosch processes. These different ammonia production processes are often described with color descriptions to designate the processes used and qualitatively identify their carbon footprint, such as “green ammonia”,... A. Blaylock |
20. Fertilizer Industry Update – Markets, Trends, and New DirectionsThe fertilizer industry was characterized, perhaps above all else, as volatile. We saw near record prices as supply chains were affected by war in Ukraine, international sanctions, and high production costs. Across the industry, fertilizer manufacturers and suppliers seek to cut operating costs to cope with rapidly falling prices. We will review key market drivers and other industry trends. ... A. Blaylock |