Autoria: MENDES, I. de C.; REIS JUNIOR, F. B. dos

Resumo: ABSTRACT: Every factor that has a negative impact on soil microorganisms sooner or later will reflect in a deterioration of soil chemical and physical properties specially, those related to soil organic matter losses. This paper was based on a talk presented at "The International Symposium of Indicators of Soil Quality" held on Marco Juarez-Argentina. Some of the aspects related to the concept of soil quality and biological indicators of soil quality, were reviewed. Results of the studies related to the characterization of soil microbial biomass, respiration and enzymes activities on different agroecosystems of the Cerrado region also are presented. Soil microbial biomass, microbial respiration, and the activities of soil enzymes (acid phosphatase, glucosidase and arilsufatase) have been evaluated at Embrapa Cerrados, since 1998. The objective of these studies is to determine the impact of different agricultural management systems (conventional tillage and no-tillage) on soil functioning and to evaluate the possibility of using these parameters as biological indicators of soil quality. Soil samples were collected at the 0 to 5 cm abd 5 to 20 cm depths, during the dry (August) and the rainy (January) seasons. In relation to a native Cerrado, located near the experiments, significant reductions in microbial biomass and phosphatase activity were observed in the agricultural areas. At the 0 to 5 cm depth, the no-tillage (NT) system presented higher levels of phosphatase, arilsufatase and glucosidase activities as compared to the conventional tillage (CT). These effects were related to the lack of soil mechanical preparation, fertilizers' placement, and to the accumulation of crop residues at the soil surface.

Ano de publicação: 2004

Tipo de publicação: Folhetos

Unidade: Embrapa Cerrados

Palavras-chave: Análise do Solo, Atividade Enzimática, Biiomassa, Bioquímica do Solo, Cerrado, Enzymic activity, Microbial flora, Microbiologia do Solo, População Microbiana