Proceedings
Authors
| Filter results17 paper(s) found. |
|---|
1. Predicting Plant Available Potassium using a Modified Sodium Tetraphenylboron MethodCurrent potassium (K) fertilizer. recommendations in the midwest are based primarily on the ammonium acetate exchangeable K (NH,OAc) soil test. In soils where nonexchangeable K comprises a major portion of plant available K, the ammonium acetate soil test is unreliable. Soil K extraction by sodium tetraphenylboron (Na-TPB) accesses both exchangeable and nonexchangeable K and mimics the action of K uptake by plant roots. A Na-TPB method utilizing a 5-minute extraction period is described, and the... |
2. 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... |
3. Impacts of Management, Moisture, and Phosphorus Form on Phosphorus Loss PotentialPhosphorus (P) is considered one of the major nutrients contributing to degradation of water quality in the United States. Our objectives were to examine P loss potential associated with: 1) high moisture conditions. 2) application (surface and incorporated) of manure from animals fed different diets and 3) sorption dynamics of inorganic and organic P compounds. The study of high moisture conditions evaluated the effects of near surface moisture conditions (wet and saturated), time (up to 28 days... |
4. In-Season Nitrogen Management for Corn ProductionWater quality impairment related to nitrogen (N) continues to be a concern in Iowa, including the nitrate drinking water standard, USEPA proposed surface water quality nutrient criteria, and the Gulf of Mexico hypoxia. Addressing these issues could include strict guidance for N input to corn and resultant N use practices that require very high level of management and risk, with unknown economic consequences. Rate of N application is an important ma nagement factor in corn production related to nitrat... |
5. Nitrogen Recalibration for Wheat in North DakotaThe general formula for determining N fertilizer ra te in North Dakota for about thirty-five years has been N-rate = (2.5 X Yield Potential (or Yield G oal) less credits from previous crops and soil test nitrate-N from a 2-foot soil core composite. Historically high fertilizer N costs and the ability to fertilize within fiel ds rather than whole field N management has resulted in a reexamination of N calibration data, and an effort to expand the modern N calibration database with new field experiments.... |
6. Nitrogen Recalibration for Wheat in North DakotaThe rise in grain prices and fertilizer costs, as well as the need for more soil-specific recommendations has spurred recent research into N response of wheat in North Dakota. Combining data from 1970 to 1990, together with recent studies has shown that new recommendations are in order. There is a rela tionship of wheat yield to available N. The relationship is better when residual soil nitrate is considered. Different areas of the state partition out with different response curves. Using the 'return... |
7. Evaluation of Crop Canopy Sensors as a Tool for Soybean Research and ProductionDetermining the variables that consistently increase yields in soybean  [Glycine max (L.) Merr.] continues to challenge researchers, agronomists and growers alike. Crop canopy sensors have emerged as a technology used in other cropping systems to monitor and manage agricultural inputs. The sensors measure reflectance in selected wavebands that are used to calculate vegetation indices that relate to unique leaf or canopy characteristics. The objectives of this study were to determine if a commercially... |
8. Assessing Nitrogen Management and Claypan Soil Variability Effects on Switchgrass using Reflectance SensingThe topsoil depth or depth to the claypan (DTC) can be highly variable across the landscape for some Midwest soils. This makes managing crops on these soils difficult because their productivity can be highly variable. In some ar eas of the landscape there can be no topsoil and leave the claypan exposed (e.g., side-slope) while in other areas it can be buried (e.g., toe-slope) (Kitchen et al., 1999). Due to the high variability of theses soils, switchgrass (Panicum virgatum L.) is a potential problem... |
9. Nitrogen Recalibration for Spring Wheat and Durum in North DakotaNorth Dakota will begin using new fertilizer r ecommendations beginning Dec. 1, 2009. Previous recommendations required a yield guess by growers with no rega rd to economics of nitrogen application. The new recommendations recogni ze different N response curves with yield and grain protein within three state agri-climatology zones. The reco mmendations use the "return to N" method, which vary the N recommendation based on crop price and N costs. The resulting rate is adjusted based on... D. Franzen, G. Endres, J. Lukach, R. Ashley, J. Staricka, K. Mckay |
10. Using Soil Properties to Predict Soluable Phosphorus Losses from Indiana SoilsEscessive phosphorus (P) levels in surface water can degrade water quality by causing algal blooms and accelerating the eutrophication process. Agriculture has bceri implicated as a major nonpoint source of P, so many states have considered restricting P applications from inorganic fertilizers, manures, and other Pcontaining materials once soil test P levels esceed "threshold values". Relationships between soil properties and soluble P loss potential have not been welldocumcnted. This laboratory... |
11. Iowa Soybean Nitrogen Fixation Consider in Nitrogen BudgetsSoybean (Glycine max) is one of the most important agricultural commodities grown in Midwestern states of the US and some other parts of the world. Like many other legumes, soybean can associate symbiotically with nitrogen (N) fixing bacteria, which can transform the N2 from the atmosphere into NH3 a more available N form, through a process known as biological N fixation (BNF). However, BNF is an energy expensive process for soybean that requires carbohydrates from... S. Cordova, R. Dietzel, M. Licht, S. Archontoulis, M. Castellano |
12. Biochemical Soil Health Indicators Related to Economic Optimum Nitrogen Rate in CornIn corn production, nitrogen (N) fertilization is one of the main inputs to enhance yield. However, in the last few years, reducing N utilization has been a goal due to environmental concerns and production costs. Soil health tests have been studied to understand the relationship with N availability and its use to adjust N recommendation rates. The objective of this study was to evaluate the relationship of different soil tests with the economic optimum N rate (N) for corn in Wisconsin. Soil samples... D. Orjuela diaz, C.A. Laboski, F. Arriaga |
13. Does Nitrogen Management in Winter Wheat Affects Its Yield and Nitrate-N Leaching in a Wheat-Soybean Double Cropping System?Conventional corn (Zea mays L.)-soybean (Glycine max L.) rotation contributes to nitrate-N and phosphate leaching to waterbodies causing water quality concerns. Two strategies that could minimize N and P losses include (i) incorporating winter rye (Secale cereale L.) (WR) as a cover crop to capture residual nutrients or (ii) intensifying the corn-soybean rotation with winter wheat (WW) (Triticum aestivum L.) (Double cropping). Double cropping WW at a right N... A. Sadeghpour, O. Ola, O. Guzel, K.L. Gage, K. Williard, J. Schoonover, S. Mueller |
14. Employing Statistical Models to Determine the Soil Tests and/or Soil Characteristics That Improved EONR Prediction in CornIn corn production, nitrogen (N) fertilization is crucial for increasing yield. However, in the last few years, there has been a push to use less N due to environmental concerns and production costs. There has been an interest in using soil health tests to predict N mineralization potential and further understand soil N availability to adjust N recommendation rates. Different statistical models like regression or decision tree analysis have been used to determine how the Economic Optimum N Rate... D. Orjuela diaz, C.A. Laboski, F. Arriaga |
15. 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 |
16. Short Term Effect of Double Cropping and Cover Cropping on Soil Physical PropertiesIntegrating cover crops into corn (Zea mays L.)-soybean (Glycine max L.) rotation has been promoted as a sustainable practice to reduce soil erosion, enhance soil health, and improve agricultural sustainability. However, growers are less inclined to include cover crops into their cash crop rotations especially winter cereals such as winter rye (Secale cereale L.) behind corn. One strategy to minimize the fallow period in corn-soybean rotation is by intensifying the corn-soybean... F. Sheikhi shahrivar, O. Ola, O. Guzel, K. Gage, K. Williard, J. Schoonover, S. Mueller, A. Sadeghpour |
17. The Effect of Nitrogen Management in Winter Wheat on Nitrous Oxide Emissions in a Wheat-Soybean Double Cropping SystemNitrogen fertilizer management plays a critical role in nitrous oxide (N₂O) emissions in agricultural production systems. This study investigated the impact of nitrogen application in a winter wheat (Triticum aestivum L.)-soybean (Glycine max L.) double cropping system on winter wheat biomass production, grain yield, and N₂O emissions. The experiment was conducted at the Agronomy Research Center (ARC), Carbondale in Southern Illinois University, IL using a Randomized Complete... O. Ola, O. Guzel, K. Gage, K. Williard, J. Schoonover, S. Mueller, A. Sadeghpour |