Proceedings
Year
| Filter results40 paper(s) found. |
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1. 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 Novi... L. Bastos, R. Ferguson |
2. Chemistry of Soil Phosphorus - Agronomic and Environmental ImplicationsTo be available for uptake by crop plants or to stimulate algal growth in a eutrophic environment, P must in a dissolved form. Therefore, in the absence of soil erosion, chemical processes that can transfer phosphate ions from the soil solution to the solid phase can limit P bioavailability and mobility. These processes include exchange, adsorption, and precipitation reactions. This presentation focuses on how local fluctuations in soil water content, solution pH, redox potential, and dissolv... M. Thompson |
3. Comparative N and Dry Matter Dynamics in Corn Ears, Stems, and Leaves During the Critical Period After Early and Late-split Sidedress NThere is currently great interest in the possible agronomic and environmental benefits of split N applications that include a late vegetative sidedress timing. The objective of this study was to determine the impact of N rate and timing of N application on the accumulation of N and dry matter in the ears, stems, and leaves of corn during the critical period (encompassing the period two weeks before to two weeks after silking) in order to understand the differing sensitivity to N stress in the... S. Mueller, T. Vyn |
4. Corn Nitrogen Calibration in South DakotaSouth Dakota (SD) corn nitrogen (N) rate recommendations were last established in 1991 and based on the coefficient of 1.2 lbs N/bu of the yield goal. The South Dakota corn N rate calculator subtracts the pre-plant soil test NO3-N (0-2ft) and legume credits and adds 30 lbs N/a for recently established no-till. Much improved corn genetics, shifting farming practices, and climate changes warrant re-calibration of corn N rate recommendations. During 2013-2105, N rate studies were conducted at 20... A. Bly, S. Berg |
5. Do Soil Tests Predict Yield Response to Phosphorus in Modern Corn and Soybean Production?Modern corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems produce higher yields, and consequently, may remove more nutrients than fertilizer rates based upon existing soil test recommendations for these yields. With greater emphasis on soil test levels for nutrient stewardship strategies, soil tests need to also predict critical levels in which fertilized nutrient responses are likely. Current soil test recommendations for Illinois have negl... T. Beyrer, F. Below |
6. Effects of Applied Soil Micronutrients on Corn and Soybean Yields in Eastern South Dakota EnvironmentsMicronutrients although taken up by plants in small quantities, their deficiencies can have significant detrimental effects on grain yield. As growers aim for maximum corn and soybean yields, availability of micronutrients in agricultural market both as individual source or combined with other secondary nutrients have also increased. However, effects of micronutrients on corn and soybean grain yields are not well documented for South Dakota (SD) soils, and growers seem to be concerned if appl... D. Karki, A. Bly, S. Berg |
7. Evaluation of Four Iron Sources for the Control of Iron Deficiency Chlorosis in SoybeanIron deficiency chlorosis (IDC) is a destructive disorder of soybeans grown on calcareous soils in the North Central region. Certain chelates are effective at preventing IDC, but the quality of commercial-grade materials varies. The objective of this greenhouse study was to compare the ability of four commercial iron fertilizers to prevent IDC in soybeans. The four sources were a high-quality FeEDDHA product (FeEDDHA-1), an FeEDDHA product of lower quality (FeEDDHA-2), FeEDDHSA, and FeHBED. T... H. Ohm, R. Goos |
8. Evaluation of Polyhalite as a Source of Potassium and Sulfur for a Corn-Soybean Rotation in MinnesotaPolyhalite contains K, S, Mg, and Ca which could be used as a source of nutrients for crops in Minnesota. The objective of this research was to determine if polyhalite can utilized within for a two-year corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Field studies were established at two locations in Minnesota with the soil test K of <120 ppm (0-6 inch sample extracted with 1M NH4OAC) and where a response to S was expected. Treatments were polyhali... A. Sutradhar, D. Kaiser, C. Rosen |
9. Fall Nitrogen for Winter Wheat Production?Fall nitrogen (N) applications are typically not recommended in Kentucky unless previous corn yields exceed 30 bu/A more than expected or when wheat is planted later than optimal in combination with a wet fall. In 2016, much of Kentucky experienced this combination of yield and environmental conditions. A study was initiated to test the need for fall applied N and how much fall N may be needed. Wheat was planted at recommended (normal) dates and then at dates that would be considered later th... E. Ritchey, J. Grove |
10. Impact of Nitrogen Application Timing on Corn ProductionWater quality issues have renewed interest in timing of nitrogen (N) application as a means to improve use efficiency in corn and reduce losses. Improved economic return is also desired as N fertilization is one of the most costly inputs to corn production. Time of fertilizer application is a component of the site-specific 4R nutrient management stewardship programs. In Iowa, the Nutrient Reduction Strategy has a 7% (37% std. dev.) nitrate-N reduction with a 0% (3% std. dev.) corn yield chang... J. Sawyer, D. Barker, J. Lundvall |