Francisco de Assis Braga

Physical attributes of distroferric red latosol under four eucalypt species over the long term

Planted forests have been increasingly highlighted in the Brazilian scenario, maintaining status regarding their environmental effects, among them those related with soils. The objectives of this work were to evaluate and to compare the physical attributes of a typic distroferric Red Latosol under Eucalyptus cloeziana, E. grandis, E. Pilularis and Corymbia maculata coverage, 37 years after being planted at the Federal University of Lavras campus. The soil profiles were sampled down to 1 m depth in order to analyze their particle-size distribution, porosity, structure and water retention. The results were submitted to analysis of variance, Scott-Knott multiple means comparison test, correlations and linear regression. The profiles presented appropriated soil physical conditions to provide good plant development. The bulk density and microporosity increased in depth while the total pore volume, macroporosity and aggregates stability decreased in depth. The soil profiles under E. cloeziana and C. maculata coverage presented lower density, more pores, are more structured, present lower water retention capability and lower water availability than the soil profiles under E. grandis and E. pilularis.

BIOMASSA E ATIVIDADE MICROBIANA SOB DIFERENTES COBERTURAS FLORESTAIS

This study evaluated the soil fertility, biomass and microbial activity of the soil under forest cover of Eucalyptus grandis, Eucalyptus pilularis, Eucalyptus cloeziana and Corymbia maculata; Pinus Caribbean var. hondurensis, 40 years old, and a fragment of Semideciduous Forest, located on the campus of the Federal University of Lavras. In soil samples collected in the 0-5 cm layer were determined fertility parameters, basal respiration and microbial biomass carbon. The results showed that for the species E. grandis and E. cloeziana the carbon of biomass microbial content was higher than for any other ecosystem evaluated, and equal to those observed under native forest. In contrast, the ground under Pinus had the lowest microbiological indexes. Under C. maculata and E. pilularis the contents were intermediate for this parameter. The basal respiration of all ecosystems was equal. The fertility level was very low in all types of evaluated vegetation.