Resumo

MOGOLLON, José Pastor; TORRES, Duilio  e  MARTINEZ, Alicia. Changes in some biological properties of soils under different land uses in El Cebollal zone, Falcon State, Venezuela. Bioagro [online]. 2010, vol.22, n.3, pp.217-222. ISSN 1316-3361.

Soil biological activity may reflect the state of soil degradation, and it is influenced by the type of land use. The objective of this research was to evaluate the impact of the predominant types of land use in El Cebollal area, Falcon State , Venezuela, by the quantification of some biological properties. Three kinds of land uses were evaluated: 1) conventional, by growing muskmelon under usual tillage and chemical fertilization, 2) alternative, by growing aloe under minimal tillage and organic management, and 3) a non altered for ten years secondary forest, as a reference soil. The soil basal respiration, soil carbon biomass, and soil urease activity were determined. It was found that muskmelon under conventional management represented the land use with the most degraded soil, showing a lower soil basal respiration (12.29 μg C-CO₂ g^-1 suelo·h^-1), lower microbial biomass (238 µg C g^-1 soil), and lower urease activity (10.2 µg NH₄ g^-1·2h^-1), as compared to the secondary forest, which showed the largest values of soil basal  respiration  (27.16 μg C-CO₂ g^-1 suelo·h^-1),  soil  carbon  biomass  (510.5 µg C g^-1 soil)  and  urease  activity (57.2 µg NH₄ g^-1·2h^-1). The land use with organic aloe showed intermediate values, with greater biological activity and greater organic matter content than the conventional management.

Palavras-chave : Urease activity; microbial biomass; biological degradation; soil basal respiration.