The experiment was conducted on the Purdue University Agronomy Farm during the summer of 1973. Plots with varying amounts of ground cover were established by having five different plant populations for both corn and soybeans. The corn populations were 0, 15, 30, 60 and 90 thousand plants per hectare. The soybean plots were planted with row widths of 25, 50, 75, and 100 centimeters; there were also plots with no soybeans (bare soil). This experiment was a continuation and expansion of the 1972 Ground Cover experiment.