Proceedings
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| Filter results7 paper(s) found. |
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1. In-Field Determination of Anhydrous Ammonia Applicator Accuracy in NebraskaLiquid and dry fertilizer applicators have been studied for their application patterns and precision. However, anhydrous ammonia (AA) applicators are generally considered less accurate. Due to the difficulty of calibration, actual application errors have not been documented. In order determine if AA applicators were delivering the intended application rate, a standard AA nurse tank was fitted with load cells, temperature, pressure, travel speed and travel distance sensors. Initial data from 55 farmer... |
2. Site-Specific Management of N Fertilization in OntarioSignificant within field variability of soil properties, such as soil fertility, and plant growth have been well docome~ited. Standard soil testing practices and fertilizer recommendations which enco~npass an average soil test value for a field and a constant rate of fertilization will obviously result in certain areas of a field being either over or under fertilized. As indicated by Kachanoski and Fairchild (1995), for a single (constant) rate of fertilizer application, reconimendations based on... |
3. Variability of Soil Test Phophorus and Management of Phosphorus FertilizerSoil avdable phosphorus (P) can have appreciable spatial variation wluch could result in inefficient ferthzer use. The hlgh cost of mapping ttus variab&ty may make sit2 spedc management of P uneconomic. Seed-placing a small amount of P fertrli2er has been shown to increase gain yield of corn. Therefore. it may have potential for improving P use efficiency. Ah txperiment was conducted to evaluate the spatial pattern of soil test P and the spatial response of applied P fertilizer. The scale of P variability... |
4. Spatial Variability of Soil Test Phosphorus, Potassium, pH and Organic Matter ContentAs part of a larger study investigating the potential for variable fertilizer N application in corn production, 18 field sites were established on farms across Ontario intensively sampled in the 1995 and 1996 field seasons to assess the spatial variability of soil test P, K, pH and organic matter content. Soil parameters typically display a log-normal distribution (positive skew) which would generally result in the under-fertilization of a greater area of a field if the rate of fertilization was... |
5. Impact of Liquid Hog Manure and Inorganic Phosphorus (P) Fertilizer Additions on Soil Test P and P Uptake by RyegrassOntario recently introduced a phosphorus (P) index to assess the relative risk of surface water contamination resulting from P application to cropland, and to suggest possible management strategies and application restrictions to reduce this risk. The index incorporates various soiVsite characteristics (soil test P level, erosionlmnoff potential etc.) as well as management practices (rate and method of P application). Within the development of the P index, questions were raised regarding the relative... |
6. Visual Correlation of Aerial Imagery with Topography and Crop YieldA study is currently being conducted on several farms to evaluate the usefulness of aerial imagery of soil and of a growing crop to delineate within-field management zones for the purposes of site-specific management. Presented is information for one site in Kent county Ontario for which correlations between aerial images taken of the soil and of the growing crop with the spatial patterns of measured topography, soil texture, and corn yield were examined. Visual interpretation indicated a very good... |
7. Utilizing Inhibitor Technology to reduce Ammonia Volatilization Losses from Urea Sources Applied to Conservation TillageA severe limitation to urea fertilizers and the ureacomponent in livestock wastes is the high potential for volatile loss of nitrogen (N) as ammonia. Losses are especially severe when the urea-containing materials are surface applied with no or only limited subsequent incorporation. Extensive losses are also observed when urea is applied to warm soils that are moist and undergoing rapid drylng. Soil pH, the presence of an active microbial population, and soil texture are also known to impact volatilization... |