| Land use and soil management may affect both labile and humified soil organic matter (SOM) fractions, but the magnitude of these changes is poorly known in subtropical environments. This study investigated effects of four land use and soil management systems (forest, native pasture, and conventional tillage and no-tillage in a wheat/soybean succession) on (i) total soil organic carbon (SOC) stocks (0 to 250mm depth) and on (ii) carbon (C) stocks in labile (coarse, light) and humified (mineral-associated, humic substances) SOM fractions (0 to 25mm depth), in a Hapludox soil from southern Brazil. In comparison to the adjacent forest site, conventionally tilled soil presented 36% (46.2Mg ha-1) less SOC in the 0 to 250mm depth and a widespread decrease in C... |
