An oats (Avena sativa L.) – no-till soybean [Glycine max (L.) Merr.] ecofarming system was evaluated through four, 2-yr rotations during 1978 through 1982. Herbicides were applied to oats, to oat stubble, and to no-till soybeans for maximum weed control throughout the 2-yr rotation. The treatment sets also included conventional tillage of oat stubble for weed control and preparation of a soybean seedbed. Several herbicides gave effective weed control in oats with minimal crop injury; however, grain yield was not increased by any of the treatments. No recropping problems were encountered when planting no-till soybeans 14 months after application of chlorsulfuron {<2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide)}. Soybean yield under ecofarming was greater 1 yr and equal to that with the conventional-tillage system the other 2 yr.