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Cropping systems were: corn + atrazine + EPTC/dichlormid; corn + atrazine + metolachlor; corn + atrazine + bentazon; corn + EPTC/dichlormid intercropped with red clover as green manure or managed as forage crop in the following year; alfalfa + EPTC; soybean + metalachlor + metribuzin; sorghum as green manure followed by winter wheat; and spring barley + diclofop-methyl + bromoxynil. Control treatments were yellow nutsedge growing in a pure stand and complete yellow nutsedge control. After two growing seasons in experiment #1, the tuber population had decreased in all cropping systems. Yellow nutsedge was reduced to 9% of the initial population under perfect control while it tripled in the pure stand. After the first growing season in the second experiment, only corn intercropped with red clover significantly reduced yellow nutsedge population by 17%. When the systems were not treated with herbicides, the yellow nutsedge population increased between 41 to 180% in all cropping systems. There was a significant relation between yellow nutsedge, broadleaf weed and grass densities and yellow nutsedge tuber production. Corn was the most profitable cropping system. The least economically advantageous cropping system was barley.