Effects of winter crops and rotation systems on some agronomic characteristics of soybean

Abstract

The effects of winter crops and rotation systems on some agronomic characteristics of soybean were assessed at the Cooperativa Agrária Mista Entre Rios Ltda., in Guarapuava, State of Paraná, Brazil. Four cropping systems to soybean were tested: I) monoculture soybean/barley; II) rotation soybean/corn in sucession of barley/commom vetch, from 1984 to 1989, and rotation soybean in sucession of barley/white oats, from 1990 to 1993; III) rotation soybean/soybean/corn in sucession of barley/flax/commom vetch, from 1984 to 1989, and rotation soybean/corn/soybean in sucession of barley/commom vetch/white oats, from 1990 to 1993; and IV) rotation soybean/soybean/corn/soybean in sucession of barley/flax/commom vetch/white oats. Both winter and summer were grown under no-tillage, except in 1989 when limestone was applied before planting winter crops. A completly randomized block design with four replications and plots with 60 m² was used. Soybean crop can be cultivated after white oats and barley, with no restriction. Differences in the mean agronomic characteristics evaluated were observed on rotation systems studied.