ECONOMIC-ANALYSIS OF CROP-ROTATION SYSTEM S FOR WHEAT, OVER A 2-YEAR PERIOD, UNDER NO-TILLAGE

This work was carried out from 1984 to 1991, at the Cooperativa Agrari a Mista Entre Rios Ltda., in Guarapuava, PR, Brazil, with the purpose of analysing economically the effect of crop rotation systems for whea t (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 oat s/soybean, from 1990 to 1991); and system IV (wheat/soybean, legume/co rn, barley/soybean, and white oats/soybean). The experimental design w as a randomized, blocks with four replications and plots with 60 m(2). Both winter and summer crops were sown under no-tillage. Economic ana lysis from 1990/1991 to 1991/1992 is presented in this paper. In the a verage of years, the gross return of system I (US$ 642.61) did not dif fer from system II (US$ 618.11). On the other hand, gross returns of s ystems I and II were higher than those of systems III (US$ 488.16) and IV (US$ 513.51).