FIELD EVALUATION OF THE EFFECT OF SOIL EROSION ON CROP PRODUCTIVITY (CLASSES, PHASES, LOSS, WATER USE, INDIANA)
Abstract
The purpose of this study was to develop a standardized sampling procedure and to obtain quantitative yield information on the effect of past soil erosion on crop productivity. The U.S. Department of Agriculture (Agriculture Research Service and Soil Conservation Service) and Purdue University conducted a 3-year investigation on this subject from 1981-1983. Yield data were collected for corn (Zea mays L.) and soybeans (Glycine max L.) grown on soils of three erosion classes. Three Indiana counties were involved with the following soils: Corwin, a fine-loamy, mixed, mesic, Typic Argiudoll; and two Typic Hapludalfs, Miami, a fine-loamy, mixed, mesic; and Morley, a fine, mixed, mesic. Crop yields were evaluated on erosion classes of slight, moderate, and severe. For each class, three replications were made in each of five fields in each county. In 1981, soil samples from the upper 15 cm of the soil were analyzed for soil pH and the content of organic matter, phosphorus and potassium. Corn yields for the Miami soil were 21 and 23 percent lower on the severely eroded sites as compared to the slightly eroded sites in 1981 and 1982, respectively. In 1982 the Corwin and Morley soils had 16 and 34 percent lower corn yields, respectively, on the severely eroded sites as compared to the slightly eroded sites. Three-year average corn yields for slight and moderate erosion phases were significantly greater than for the severely eroded phase. Organic matter and phosphorus contents were highest for slightly eroded soils and lowest for severely eroded soils. Potential plant-available water was least for the severely eroded sites. Extensive corn yield data collected in 1982 were used to develop a procedure for estimating corn yield on three erosion phases by counting ears and harvesting a fraction of them. The method is simple, and the data are obtained with minimal time in the field. The overall coefficient of determination was 0.978, and the coefficient of variability was 4.7% for yield estimates based on weights and moisture content of every fifth harvestable ear.
Degree
Ph.D.
Subject Area
Agronomy
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