Cultural productivity of crop rotation systems for barley, under no-tillage

Abstract

Over a ten-year period (1984 to 1993), in Guarapuava, Paraná, Brazil, the effect of crop rotation systems on barley was assessed. Four rotation systems for barley were studied: system I (barley/ soybean); system II (barley/soybean and common vetch/com, 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; common vetch/corn was replaced by white oats/soybean, from 1990 to 1993); and system IV (barley/soybean, flax/soybean, common vetch/com, and white oats/soybean). The objective of this work was to evaluate the cultural productivity of these flour rotation systems under no-tillage. From 1984 to 1989, the systems 11 (2.19 kg/Mcal) and 111 (1.89 kg/Meal) showed a higher energy conversion rate, as compared to system 1 (1.54 kg/Mcal). No difference was found between systems IV (1.81 kg/Mcal) and 1. From 1990 to 1993 the systems 11, 111 and IV, whose average cultural productivity indexes were 1.89 kg/Mcal, 2.02 kg/Mcal, and 1.88 kg/Mcal, respectively, did not differ from system 1 (1.68 kg/Mcal); however, the annual cultural productivity indexes of systems III and II were either higher than or did not differ from systern I.