THE ROOT SYSTEM OF Urochloa brizantha: DEVELOPMENT AND INFLUENCE ON THE ATTRIBUTES OF A DEGRADED SOIL

The use of cover crops characterized. by abundant root system with fast and continuous growth, such as the Urochloa brizantha, can provide chemical and physical significant improvements to the soil. Thus, the use of cover crops becomes a viable alternative to recovery soils degraded by mining This study aimed to analyze the root dynamics of Urochloa brizantha and its.influence in physical -chemical attributes of a soil degraded by coal mining, in two field experiments installed in 2003 and 2007, respectively. Root and soil samples were collected on July 2012, to a 0.30m depth. The Urochloa brizantha showed root development to a 0.30m depth after 58 months of implantation. The root biomass increased in the layers of 0.00-0.10m and 0.10-0.20m after this period. Changes in physical attributes and organic carbon content of the mine soil are slow, indicating that even if the root system continues its expansion in deeper layers, the interrelationships with other organisms of the degraded soil are still incipient. It is suggested to perform an edaphic fauna survey in different layers of soils degraded by mining the, aiming to estimate their contribution to the root system decomposition and in to the improvement of the physical conditions of the soil.