Crop rotation and succession systems lesser the risk level due to diversification of cultivities. Soil tillage and crop rotation and succession systems were assessed in Passo Fundo, RS, Brazil, from 1994/95 to 1997/98. Four soil tillage systems - 1) no-tillage, 2) minimum tillage, 3) conventional tillage using a disk plow, and 4) conventional tillage using a moldboard plow - and three crop rotation and succession systems [system I (wheat/soybean), system II (wheat/soybean and common vetch/sorghum or corn), and system III (wheat/soybean, common vetch/sorghum or corn, and white oats/soybean)] were compared. An experimental design of randomized blocks with split-plots and three replications was used. The main plot was formed by the soil tillage systems, while the split-plots consisted of the crop rotation and succession systems. Two types of analysis were applied to the net return of soil tillage and crop rotation and succession systems: mean-variance and risk analysis. By the mean-variance analysis, no-tillage and minimum tillage, which presented higher net return, were the best alternatives to be offered to the farmer. By the stochastic dominance analysis, no-tillage and crop rotation with two winters without wheat showed the highest profit and the lowest risk.
net return; mean-variance; stochastic dominance; crop rotation; conventional tillage; minimum tillage; no-tillage
