Sustainable Production Systems under No-till in the Cerrado of Brazil - Piaui

This project was conducted for three years, and 2014 represented the last year of the study. Continuation will not be possible due to many changes in the research team. In 2014, a severe drought occurred in several regions of the state, including the site of the project.

After three years, a soybean crop followed by millet provided the greatest addition of biomass to the soil. No increase in soybean yield has been observed in this rotation despite an apparent increase in soil K recycling. Soybean followed by brachiaria showed an increase in grain yield over the period studied, especially with treatments where maize was cultivated before soybean and had N fertilizer input. Soybean followed by sun hemp did not show any grain yield increase. For maize associated with brachiaria grass, a linear response in grain yield was observed with N fertilizer input. Monoculture maize plus N promoted a grain yield increase. Furthermore, two harvests of maize in 2012 and 2013 with increasing rates of N did not reflect in an increase in soybean grain yield in 2014.