Atributos físicos, químicos e biológicos do solo em sistemas de integração lavoura-pecuária-floresta

Abstract

Integrated systems have become common in several regions of Brazil and studies on the effects of these systems on soil attributes have intensified. However, there are still doubts about their impacts on the environment due to the use and applied management, such as machine traffic and animal trampling. This study aimed to detect changes in physical, chemical and biological soil attributes caused by the implantation of integrated crop-livestock-forestry systems (iCLF) and to identify those attributes that are suitable for detecting changes in soil quality. Soil samples were collected in the 0-0.10 m layers in Nova Canaã do Norte, MT, and Cachoeira Dourada, GO, in areas of iCLF with one (iCLF1) or three (iCLF3) eucalyptus rows in each tree set and in areas of recovered and degraded pasture. In areas under iCLF, the samplings were carried out on several positions in relation to the tree rows. The higher soil physical quality under iCLF1 and recovered pasture was responsible for its discrimination from the other environments. Potassium content, soil microbial biomass carbon and nitrogen as well as soil basal respiration were efficient in discriminating degraded pasture from integrated systems and recovered pasture. The integrated systems, with three or four years of implantation, have contributed to improving the soil physical quality, but have not yet been able to interfere markedly on its biological quality in relation to the degraded pasture.