The Influence of Alfalfa, Bromegrass, and Corn on Soil Aggregation and Crop Yield
1959
Barber, Stanley A.
The influence of alfalfa, bromegrass and a mixture of the two on soil structure was investigated in an experiment in which each crop was grown for 1, 2, 3, and 4 years. Continuous corn was also grown. All plots were heavily fertilized in an attempt to avoid yield differences due to nutrient factors. Soil samples for physical analyses were taken in each of two years. Percentages of water-stable aggregates were determined. The aggregation index obtained by this procedure was higher after bromegrass than after alfalfa and higher after alfalfa than after corn. The alfalfa-bromegrass mixture gave a value intermediate between alfalfa and bromegrass. The aggregation index increased in a linear fashion with each additional year of bromegrass or alfalfa up to the 4 years used in the experiment. The aggregation index was not affected by the number of years of corn. Preliminary data indicate that corn yields were affected little by the aggregation index.
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