ECONOMIC-ANALYSIS OF CROP-ROTATION SYSTEM S FOR BARLEY, UNDER NO-TILLAGE

From 1984 to 1993, in Guarapuava, PR, Brazil, the effects of crop rota tion systems on barley were assessed. The economic analysis of these s ystems is presented in this paper. Four rotation systems for barley we re studied: system I (barley/soybean); system II (barley/soybean and c ommon vetch/corn, from 1984 to 1989, and barley/soybean and white oats /soybean, from 1990 to 1993); system III (barley/soybean, flax/soybean , and common vetch/corn, from 1984 to 1989, and barley/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1993); and system IV (barley/soybean, flax/soybean, common vetch/soybean, and white oats/s oybean). From 1984 to 1989, systems I (R$ 196,76), II (R$ 293,26), III (R$ 242,69), and IV (R$ 239,55) did not differ significantly for net return. Similarly, from 1990 to 1993, systems II, III and IV, whose me an net returns were R$ 447,62, R$ 400,46, and R$ 349,43, respectively, showed no significant differences in relation to system I (R$ 370,04) . Nevertheless, the annual net returns of system II, in both periods u nder study, make it the best alternative, since they were superior to or did not differ from the remaining systems studied.