Analysis of the cultural productivity of crop rotation systems for wheat, under no-tillage

Abstract

From 1984 to 1993, in Guarapuava, PR, Brazil, the effect of systems of crop rotation on wheat was assessed. Four rotation systems for wheat were studied: system I (wheat/soybean); system II (wheat/soybean, common vetch/corn, from 1984 to 1989, and wheat/soybean, white oats/soybean, from 1990 to 1993); 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 1993); and system IV (wheat/soybean, legume/corn, barley/soybean, and white oats/soybean). Cultural productivity (kg of commodity/Mcal consumed) during that period is presentend in this paper. From 1984 to 1989, systems II (2.20 kg/Mcal), III (1.91 kg/Mcal), and IV (1.83 kg/Mcal) showed a higher conversion rate, as compared to system I (1.52 kg/Mcal); system II was the best option. From 1990 to 1993 systems II, III, and IV, whose average cultural productivity indexes were 1.93 kg/Mcal, 1.96 kg/Mcal, and 1.91 kg/Mcal, respectively, did not differ from system I (1.78 kg/Mcal); however, the annual cultural productivity indexes of system II showed no difference from system II or exceeded it, becoming, therefore, a good alternative to replace wheat/soybean monoculture.