In a two-year field experiment, sweet corn was intercropped with a perennial cover of white clover. The clover was suppressed after corn emergence by rototilling. The nitrogen exchange between the corn, clover, and soil was closely monitored. Soil sampling indicated the rate and amounts of mineralization of nitrogen from soil organic matter and clover. Fertilizer labelled with 15-N was used to assess contributions of nitrogen from the various sources.
Results from 1989 showed little nitrogen benefit to the corn from the clover. Content of 15-N in the corn indicated that non-fertilizer nitrogen uptake was similar in monocropped and intercropped corn treatments. Corn yields were correlated with the amount of nitrogen fertilizer applied.
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