Even though windbreaks benefit in agricultural systems by protecting crops from damaging effects of wind and controlling soil erosion, some farmers are reluctant to plant windbreaks in their fields because of the reduction of crop yields in the area close to the windbreaks due to tree competition. Windbreaksoybean competition for soil moisture and light was studied during two crop seasons (1996 and 1997) at Mead, Nebraska. The effects of windbreak orientations (east, west and south windbreaks), and the effects of tree root pruning (pruned and non-pruned) on soybean growth and yield were studied. Windbreaks were mature trees formed by two rows of green ash combined with eastern redcedar or Austrian pine. Tree root pruning was done at 7 m from the windbreak line and at 0.75 m depth. Neither irrigation nor fertilization were applied on soybean in either crop season.