Proceedings
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| Filter results9 paper(s) found. |
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1. 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... |
2. 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... |
3. 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... |
4. 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... |
5. 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... |
6. Sustainable Vegetable Crop Production Using Vermi-CompostThis research intends to utili ze earthworm castings as an alternate nutrient source, especially nitrogen, for vegetable crop production. The experiment was conducted in the greenhouse and 'Mountain Fresh' tomato ( Lycopersicon esculentum Mill.) was used as the test crop. The main objectives were (1) to identify the optimum app lication rate of earthworm castings (EC) for tomato growth, and (2) to compare tomato res ponse under different treatments. Three different textural soils, namely sandy soil,... |
7. Crop Sensors as In-season Nitrogen Management Tool for Winter Wheat in WisconsinIn Wisconsin, current winter wheat (Triticum aestivum L.) nitrogen (N) rate guidelines are determined by soil type, previous crop, and pre-plant soil nitrate test (PPNT). Nitrogen management may be improved through site-specific assessments of N need in the spring, offering a more effective use of top-dressed N. The study objective was to determine if crop reflectance measurements could be used to determine optimal in-season N rates on silt loam soils in eastern Wisconsin. This study evaluated the... |
8. Nitrogen Management: Unraveling the Effect of Timing and FormImprovement of nitrogen use efficiency by co rn production would decrease the potential for nitrogen loss into the environment. A study ha s been conducted in Ames, Iowa on 16 different forms and rates of nitrogen in both a continuous corn and corn-soybean production systems. There were differences among treatments; howeve r, the most consistent treatment was the SuperU applied as a 150 lb A -1 preplant or as 50 lb A-1 preplant and 100 lb A-1 sidedress and UAN with Agrotain adde d to both the 50... |
9. Methods and Limitations of Zone Sampling Using Topography as a Logical BasisTwo forty-acre fields in North Dakota were sampled in a 110 foot grid. Each field was measured for elevation in the same 110 foot grid. Topographic sampling zones were identified in each field and a correlation of the sampling based on these zones was compared to the correlation values from a 220 foot grid. Nitrate-N and the 220 foot grid were both correlated to the 110 foot sampling values for nitrate-N and P. A map of field nitrate-N levels from topography sampling compared to the 220 foot grid... |