Resumo

GIZZI, Antonio H et al. Characterization of the meso and macrofauna of a Southeastern Buenos Aires province soil under different cropping systems. Cienc. suelo [online]. 2009, vol.27, n.1, pp.1-9. ISSN 1850-2067.

The aim of this work was to determine the taxonomic composition and relative abundance of the soil meso and macrofauna and their different trophic groups as affected by soil management practices. Four cropping systems were evaluated: LC50 [(50% pasture - 50% cropping under conventional tillage (LC)], SD50 [(50% pasture - 50% cropping under no-tillage (SD)], LC75 (25% pasture - 75% cropping under LC), SD75 (25% pasture - 75% cropping under SD). In the year 2000, a pasture (P) was sown on LC50 and SD50 and in 2001 it was one year old. On LC75 and SD75, corn was planted in 2000 and soybean was planted in 2001. Most of the individuals observed in 2000 within the mesofauna were enchytraeids and their abundance was not different between LC and SD, whereas in 2001 the highest abundance of enchytraeids was observed under the 15-year-old P. Within the macrofauna, earthworms, isopods and miriapods predominated, but isopods and miriapods were dominant under P in both years. In the first year, the meso and macrofauna densities were not significantly different (p>0.003) among cropping systems, although they tended to be greater under SD. In the second year, such densities were significantly higher (p<0.003) under P. In both years, density interactions between cropping systems and fertilization rates were not significant (p>0.003) for detritivours, herbivours, predators and omnivous. Despite the lack of significant differences (p>0.003) among systems during the first year, all four trophic groups were more abundant under P and SD than under LC. In the second year, detritivours, predators, and omnivours were significantly more abundant under P than under soybean. Our results confirm that the cropping systems affected the taxonomic composition of the soil meso and macrofauna and their trophic groups. On the other hand, the abundance of both communities increased under P throughout the experiment.

Palavras-chave : Soil fauna; Tillage systems; Crop rotations; Taxonomic composition; Trophic groups; Density.

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