Results of studies made from 1977 to 1984 to control erosion by cover crops and no-tillage techniques in Paraná, Brazil

Abstract

From 1977 to 1984, the influence of tillage and cover crops on soil erosion and yield of main crops was studied on Oxisols in Paraná, Brazil. Tillage systems were no-tillage (NT), minimum tillage with a chisel plough (CP) and conventional tillage with a disc plough (CT). It was found that under NT, as compared to CT and CP, the total pore volume and coarse pore volume were lower, bulk density in the upper soil layer was higher, available moisture was higher, temperature was lower and infiltrability was higher. Percentage of soil cover was the main factor governing infiltration rate. Without soil cover the infiltration rate under NT was the same as under CP and CT. The use of cover crops and crop rotation had a marked positive effect on maize, soya bean and bean yields. Yields of wheat and soya beans were higher under NT and CP. It is concluded that in Paraná no-tillage in combination with adapted cover crops and crop rotations represents a production system which is efficient in reducing water runoff and consequently soil erosion, and in increasing crop yields.