Economic analysis of crop rotation systems for wheat, over a two-year period, under no-tillage

This work was carried out from 1984 to 1991, at the Cooperativa Agraria Mista Entre Rios Ltda., in Guarapuava, PR, Brazil, with the purpose of analysing economically the effect of crop rotation systems for wheat (Triticum aestivum L.). Four rotation systems were studied: system I (wheat/soybean); system II (wheat/soybean and common vetch/corn, from 1984 to 1989, and wheat/soybean, and white oats/soybean, from 1990 to 1991); system III(wheat/soybean, flax/soybean and common vetch/corn, from 1984 to 1989, and wheat/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1991); and system IV (wheat/soybean, legume/corn, barley/soybean, and white oats/soybean). The experimental design was a randomized, blocks with four replications and plots with 60 m(2). Both winter and summer crops were sown under no-tillage. Economic analysis from 1990/1991 to 1991/1992 is presented in this paper. In the average of years, the gross return of system I (US$ 642.61) did not differ from system II (US$ 618.11). On the other hand, gross returns of systems I and II were higher than those of systems III (US$ 488.16) and IV (US$ 513.51).