Net returns for the full-season 2000 crop treatment combinations were between $89.57/acre for the continuous rice, no-till, enhanced fertility, 'LaGrue' treatment combination and $326.71/acre for the rice following corn, conventional tillage, standard fertility, 'Wells' treatment combination. Net returns, on average, were lowest ($141.49/acre) for the continuous rice rotation and highest ($234.61/acre) for the rice following soybean rotation. Lower production costs from the no-till plots were more than offset by increased yields in the conventional till plots resulting in higher net returns for the conventional tillage plots. The enhanced fertility treatment did not result in sufficient yield gains to offset fertilizer costs, thus net returns were higher for the standard fertility treatments. Consistently higher grain yields from Wells resulted in overall higher net returns from this variety. The only short-season rice variety combination resulting in positive net returns was with the variety 'XL-6'. Overall grain yields declined from 178 bu/acre in 2000 to 158 bu/acre in 2001. The mean grain yield from the continuous rice rotation was approximately 20 bu/acre lower than rice following soybean or corn. The enhanced fertility plots yielded only 6 bu/acre more than the standard fertility treatment. Yields declined in the short-duration rice treatments with highest grain yields from the variety XL-6. Water-use measurements indicated that, on average, all rice plots used approximately 29 acre-inches of irrigation water during the season. Water savings came from a reduced need to flush no-till plots. Above-ground plant nutrient uptake values indicated that the variety Wells generally took up more nutrients when compared to LaGrue. Rotation had the biggest impact on nutrient uptake in 2000 and there was a trend of increased nutrient uptake from the enhanced fertility treatments when compared to the standard fertility treatments even though there was no increase in grain yield.
