CROP-ROTATION IN GUARAPUAVA .13. EFFECTS OF CROP SUCCESSION SYSTEMS ON YIELD AND ON OTHER AGRONOMIC CHARACTERISTICS OF SOYBEAN, UNDER NO-TILLAGE

The effects of crop succession systems on yield and on other agronomic characteristics of soybean were assessed at the Cooperativa Agraria M ista Entre Rios Ltda., in Guarapuava, Parana, Brazil. Four cropping sy stems were tested in which soybean was seeded after different winter c rops (white oat, barley, flax, and wheat) distributed in a number of c rop rotation systems. The crops were seeded under no-tillage. A random ized complete block design, with four replications, and plots with 60 m2, was used. Soybean after the succession flax, wheat, and common vet ch presented lower height of insertion of the first pods. Soybean grow n after the succession white oat, wheat, lupine, and barley showed low er plant height. Soybean following the succession wheat and common vet ch; wheat, common vetch, and flax; wheat, lupine, barley, and white oa t; wheat monoculture; barley, white oat, wheat, and lupine showed the best performance, in relation to the parameters studied.