ABSTRACT
The concepts of soil quality and agricultural sustainability must be viewed in a broad form that includes the needs for increasing agronomic productivity, improving resource conservation, and enhancing environmental quality. According to R. Lal et al., sustainable land use must be assessed in terms of its impact on soil organic carbon pool. Conversion of native vegetation to cultivated cropland under the conventional tillage system has resulted in a significant decline in soil organic matter content. The underlying land management principles that led to the development of no-tillage systems in Brazil were prevention of surface sealing caused by rainfall impact on soil surface, achievement and maintenance of an open soil structure, and reduction of the volume and velocity of surface runoff. A complete balance of greenhouse gas emissions as affected by long-term management systems was performed by Gomes in the South of Brazil.
