Soil organic carbon replenishment through long-term no-till on a Brazilian family farm

Excerpt

Deforestation and subsequent cultivation have been reported to result in loss of soil organic carbon (SOC) and soil productivity throughout the world (Matson et al. 1997). Decreased SOC due to cultivation of deforested land is well documented (Follett 2001; Janzen et al. 1998; Riezebos and Loerts 1998) and often happens two to five times faster in tropical than temperate environments (Matson et al. 1997; Six et al. 2002). Soil organic carbon decreases as a function of biomass removal, lower organic input, and greater biomass decomposition rates in the newly disturbed soil as compared to soil under native vegetation (Riezebos and Loerts 1998). The removal of native biomass also exposes the soil, rendering the surface prone to erosion (Prandini et al. 1977).

Research has shown that the high environmental costs brought by changes in land use can be lessened if conservation tillage practices are adopted (Rhoton 2000; Rimal and Lal 2009). The data collected in southern Brazil and presented in this report indicate that almost three decades of no-tillage farming practices have the ability to restore SOC to near native levels. We are reporting long-term shifts in SOC, as well as observed soil erosion, in a 60 ha (148 ac) Brazilian…