Nitrogen availability as affected by ten years of cover crop and tillage systems in southern Brazil

ABSTRACT:

Conservation tillage and cover crops are useful tools in Brazil for restoring degraded soils that resulted from the rapid expansion of agriculture without proper management during the 1970s. In 1985, a long-term study was initiated on a degraded Paleudult in the state of Rio Grande do Sul to better understand the impact of these soil management practices on nitrogen (N) dynamics in corn production systems. The systems include both conventional and no-tillage with oat/com, vetch/corn and oat + vetch/corn, + cowpea (intensive). After nine years, no-tillage with the intensive cropping system resulted in a 24% increase in soil N as compared to conventional tillage; there was no difference in corn yield between tillage systems.