The Influence of Crop Management on Runoff, Erosion, and Soil Properties of a Marshall Silty Clay Loam
1967
Moldenhauer, W. C. | Wischmeier, W. H. | Parker, D. T.
A series of field plots at Clarinda, Iowa, were operated from 1932 through 1963 to study effects of crop and soil management on infiltration, erosion, and crop yield. Major treatment changes were made in 1943 and 1953. Before 1953, soil-erosion rates were high, especially when corn (Zea mays L.) followed several years of corn, and were inversely related to organic carbon content and aggregate stability of the soil. After the 1953 revision of the study, erosion loss from continuous corn that received annual applications of 179 kg of N per ha (160 lb/acre) were relatively low and were not closely correlated with soil carbon content or with aggregate stability. However, erosion was inversely related to high nitrogen fertility, which, in turn, was accompanied by a trend toward increased soil carbon and high carbohydrate content of the soil. The erosion-reducing effect of the nitrogen additions were most evident under intense July and August thunderstorms. Soil loss from corn following good meadow was, however, substantially less than from the nitrogen-treated continuous corn, particularly when erosive rains occurred during the corn seedling stage of the crop year. Crop yield was directly related to N fertility and not to aggregate stability or to organic-matter content of the soil.
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