Proceedings
Authors
| Filter results21 paper(s) found. |
|---|
1. Profile Distribution of Available Potassium in Des Moines Lobe SoilsPlant potassium (K) concentrations and soil fertility evaluations to predict available K have received renewed attention during the past few years due to increasing interest in harvesting crop residues as feedstock for production of bioenergy and other bio-products [e.g., button mushroom (Agaricus Bisiporus) compost]. Interest in K crop nutrition has also increased as more producers adopt reduced or no-tillage production practices. This latter situation is not new, because the potential for K deficiencies... |
2. Influence of Phosphorus and Potassium Fertilization on Alfalfa Yields Under Intensive HarvestIn the northern part of the North Central (NC) states cutting management schedule and adequate fertilizer are important factors in maintaining alfalfa stands. Recent work in Minnesota by Sheaffer indicates that fall cutting poses some risks to lon-term stand persistance but should be considered as a management alternative to allow greater harvest flexibility. He further states that stand loss can be greatly reduced by high levels of fertilizer (particularly potassium). The study I am reporting on... |
3. Effect of Intensive Management Practices on Wheat Yields and ProfitabilityConsiderable interest in improving wheat yields and profitability has been shown throughout the U.S. over the past ten years. Much of this interest has resulted from the dramatic yield increases achieved by English producers during that time - an annual increase of 5.0 bushellacre per year (Figure 1). During that same time period, wheat producers in the U.S. have shown a much lower rate of increase in wheat yields - 1.02 bushellacre per year (Figure 2). Missouri growers have been no exception to... |
4. Economic Perspective on Variable Rate FertilizationSoils form a continuum across every farmer's field, constantly changing in both physical and chemical characteristics. Sometimes these changes are visible; sometimes they are completely masked to the eye. Variables such as organic matter, water-holding capacity, pH, and soil nutrient levels differ, and combined, they affect crop yield goals. In either case, these differences should result in different management practices, including fertilizer applications, being recommended for different soils within... |
5. Sidedress N applications for corn based on corn colorNitrogen-deficient corn reflects more light over the entire visible spectrum than nitrogen-suff icient corn. Our objective was to calibrate the relationship between remotely-sensed corn color and the nitrogen need of the corn. Corn color measurements were made two ways: Aerial photographs In-field spectral radiometer A successful calibration would allow: Variable-rate sidedress nitrogen applications that precisely meet the needs of the crop. Precise response to in-season N loss (Figure 1). Data reported... |
6. Evaluation of Nitrogen Management Practices in No-till Corn ProductionExperiments were conducted fiom 1995 to 1998 at the Dixon Springs Agricultural Center of the University of Illinois and the Belleville Research Center of Southern Illinois University to evaluate agronomically and economically several nitrogen (N) management options, including the use of the urease inhibitor Agrotaii, in no-till corn production. Compared in these studies were N sources (urea, UAN, ammonium nitrate, and anhydrous ammonia), placement (dribble vs. broadcast for surface-applied N and... |
7. Field Scale Evaluation of Innovative N Management Systems for CornPrevious research has shown that N fertilizer need for corn can vary widely, both between fields and within fields. Producers, however, almost always apply the same N fertilizer rate to whole fields, and vary N fertilizer rates minimally if at all over whole farms. Matching N fertilizer rates more closely to N needs could produce both economic and environmental benefits. Our objective is to test a range of innovative N management systems for their ability to match N rate recommendations to N needs... |
8. Phosphorus and Potassium Effects on Yield Components, Nutrient Accumulation and Persistence of Alfalfa (Medicago Sativa L.)Our objective was to determine why phosphorus (P) and potassiun~ (K) are essential for high yield by analyzing alfalfa yield components. Plots of P treatments (0, 25. 50, and 75 kg/ha) and K treatnients (0. 100, 200, 300, and 400 kgha) arranged in a factorial design were replicated four times. Forage was harvested four times per growi~lg season (1998-2000), and yield. mass per shoot, shoots per area. and herbage nutrient concentrations determined. In May and December, plants were dug to determine... |
9. 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 of... |
10. Corn Nitrogen Rate Response Trials in Northwest and Westcentral Minnesota, 2007=-2009With the growing number of corn producers and increased acres of corn in NW and WC Minnesota along with the revisions in the Univer sity of Minnesota Corn Nitrogen Guidelines (2006) many northern corn growers were asking a bout the validity of the new nitrogen guidelines for corn production in the region. Prior to 2007, University of Minnesota calibration and correlation data included in the new guidelines did not include any research sites north of Interstate 94. A request for funding from the Minnesota... |
11. Effect of Late-Applied N on Corn Dry Matter, N Content, and YieldNitrogen management of corn (Zea mays L.) may be improved by delaying N application until just prior to the rapid growth phase (approximately V6-V8). This timing is commonly referred to as 'sidedress'.� Some farmers do not sidedress because they are concerned inclement weather may delay N application beyond V8, requiring high clearance equipment to apply N and possibly reducing grain yield. However, few studies have investigated the effects of late-applied N in rain-fed production environments... |
12. Validating Potassium Fertilizer Guidelines in Alfalfa-corn RotationsIn 2008 to 2010, on-farm research was conducted on 10 fields with medium soil test K (STK) to validate Minnesota K fertilizer guidelines by determining the effect of K fertilizer applications on alfalfa yield and quality in its last production year, and estimating the carryover of excess fertilizer K to first-year corn. We were surprised to find that no K fertilizer was needed to maximize alfalfa yield or overall forage feed value and quality. Luxury consumption of K occurred because as K application... |
13. Soybean Production Research: A National ApproachU.S. soybean growers are looking for alternative methods to increase soybean yields and recent increases in commodity prices have given producers more freedom to invest in additional crop inputs or products. Unfortunately, quality data from studies addressing multiple contemporary inputs is scarce. The objective of this work was to evaluate the effectiveness of combined soybean inputs on seed yield. These high input systems were tested in six states to evaluate their value across a broad geography.... |
14. Soybean Response to Potassium Fertility and Fertilizer in ManitobaSoybean acres have increased greatly in Manitoba in recent years, now occupying more than 25% of the province’s annual crop land. Potassium removal by soybean is greater than any other crop grown in Manitoba (1.1 – 1.4 lb K2O/bu). This large removal, accompanied by the large and rapid expansion in soybean acres, has contributed to an increase in province-wide potassium removal rates and likely explains the increase in incidence of potassium deficiency symptoms reported in recent years.... M. Bourns, D. Flaten, J. Heard, G. Bartley |
15. Adjusting Soybean Seeding Rate and Nutrient Strategies to Promote Nutrient Uptake in Irrigated and Non-Irrigated SystemsIncreases in total dry matter accumulation (TDM) can impact soybean (Glycine max L. Merr.) grain yield. However, the relationship between nutrient uptake and dry matter (DM) across seeding rates and influences on grain yield under irrigated and non-irrigated conditions remains uncertain. Two multi-year trials were established near Lansing, MI to investigate soybean dry matter accumulation, partitioning and remobilization; nutrient accumulation, partitioning, and remobilization; grain... K. Steinke , C. Terwillegar |
16. 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 |
17. Corn Responses to Sulfur Fertilizer in IndianaCorn yield increases in response to sulfur (S) applied as ammonium thiosulfate in liquid N (in sidedress and/or starter fertilizer applications) occurred in ~40% of 40 trials conducted between 2017 and 2021 and ranged from 4 to 24 bushels per acre on responsive sites. Increased grain yield with S fertilization occurred on soils ranging in texture from sandy loam to silty clay loam and soil organic matter concentrations from ~1 to 3%. Yield increases with S fertilization were not predicted by Mehlich‑3... J. Camberato, D. Salguero, R. Nielsen |
18. Integration of Satellite and UAV Imagery for Assessing Corn Nitrogen Uptake at Early Vegetative Growth StagesNitrogen (N) fertilizer accounts for 20-25% of the variable cost of production for rotation maize in Indiana. Spatial variability within fields and variable, unpredictable rainfall patterns make N a challenging nutrient to manage, withup to 65% of the nitrogen applied being lost as nitrate. Post-emergence sidedress applications of N fertilizer can reduce N loss and improve plant uptake, so efficient and practical ways to identify maize N status at early maize growth stages is key to assessing... A. Morales Ona, R. Nielsen , J. Camberato, D. Quinn |
19. 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 |
20. Carryover Effects of Sulfur Fertilization from One Cropping Season to the NextCorn and soybean grain yield increases with S fertilization are not uncommon in Indiana. Low rates of S fertilizer (<15-20 lb S/acre) are needed to maximize grain yield response. We found that sulfate-S fertilizer applied to silt loam or heavier textured soils in one cropping season provided S to the crop grown the next season more often than not. At some S responsive locations, S applied the prior season at 15 to 20 lb S/acre produced yields of the second crop equivalent to crop yields with... J. Camberato, R. Nielsen |
21. 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 |