Effect of winter crops under no-tillage on soybean grown in crop rotation systems

Abstract

From 1984 to 1993, the effects of different crop sucession systems on yield and some agronomic characteristics of soybean (Glycine max (L.) Merril) were assessed at Cooperativa Agrária Mista Entre Rios Ltda., in Guarapuava, Paraná, Brazil. Four cropping systems were tested, in which soybean was seeded after different winter crops (white oats, barley, flax, and wheat). From 1990, in both second and third rotation systems for wheat, the sucessions common vetch/corn and flax/soybean, respectively, were replaced by white oats/soybean. Both winter and summer crops were under no-tilled, except in the winter of 1989, when limestone was applied before planting winter crops. A randomized complete block design, with four replication and plots with 60 m², was used. From 1984 to 1989, soybean grown after flax, system III, showed lower height of the first pods, lower plant height, and lower yield. Soybean grown after white oats, barley, and wheat, may be included, without losses, in the different systems studied.