Crop residues of winter species and the corn yield in the minimum tillage system

Abstract

The use of legume species as a soil cover decreases soil losses by erosion and adds N by symbiotic fixation. With the objective of determining the N supply capacity to corn of six winter soil cover crops species (Vicia sativa, Lathyrus sativus, Lupinus albus, Pisum sativum, Avena strigosa and Brassica napus) under minimum tillage, an experiment was carried out on a brunizem soil (Molisol). Two control treatments in winter fallow without and with 110 kg/ha of N were used. The experimental design was a completely randomized block with four repetitions for each treatment. Lupinus albus gave a yield of corn similar to that obtained in the treatment with mineral N (5.18 and 5.42 t/ha), respectively, and 61% higher than the winter fallow with N (3.22 t/ha). A significant relation between winter cover crops total N absorption and corn grain yield was observed, showing that in this experiment the N supply to corn is one of the major benefits of winter cover crops.