Abstract

VALPASSOS, Maria Alexandra Reis; CAVALCANTE, Eloiza Gomes Silva; CASSIOLATO, Ana Maria Rodrigues  and  ALVES, Marlene Cristina. Effects of soil management systems on soil microbial activity, bulk density and chemical properties. Pesq. agropec. bras. [online]. 2001, vol.36, n.12, pp. 1539-1545. ISSN 0100-204X.  http://dx.doi.org/10.1590/S0100-204X2001001200011.

The objective of this experiment was to study the effects of soil management systems on the bulk density, chemical soil properties, and on the soil microbial activity on a Latossolo Vermelho distrófico (Oxisol). Soil samples were collected from plots under the following management conditions: a) natural dense "cerrado" vegetation (savanna); b) degraded Brachiaria decumbens pasture, 20 years old; c) no-tillage treatment with annual crop sequence (bean, corn, soybean and dark-oat in continuous rotation), 8 years old; d) conventional tillage treatment with crop residues added to the soil, and annual crop sequence, 10 years old. The continuous use of no-tillage system resulted in an increase in microbial biomass and decrease in soil basal respiration, therefore displaying evident long-term effects on the increase of soil C content. The no-tillage system also provided an improvement in bulk density and chemical properties of the soil. Hence, the no-tillage management system could be an alternative for the conservation and maintenance of physical and chemical conditions and the productive potential of "cerrado" soils.

Keywords : soil chemicophysical properties; biomass; soil deterioration; soil conservation.