Resumo

DOMINGUEZ, Anahí; BEDANO, José Camilo  e  BECKER, Analía Rosa. Changes in the earthworm community (Annelida: Lumbricina) as a consequence of no-tillage in the south-central region of Cordoba, Argentina. Cienc. suelo [online]. 2009, vol.27, n.1, pp.11-19. ISSN 1850-2067.

No-till has been recognized as a low environmental impact management in relation to other crop systems. However, it has been suggested that no-till may produce degradation of several soil properties. The earthworm (Annelida: Lumbricina) community is a good indicator of soil quality, especially because they integrate all possible stress factors. So, the aim of this study was to evaluate the changes on the earthworm community and on several physical, chemical and physicochemical soil properties in soils under no-till in relation to natural grasslands. The study was carried out in Gral. Deheza basin, Córdoba. The earthworms were sampled by means of the TSBF program method. It was observed an increase in compaction and a decrease in organic matter content and in pH values in no-till sites in relation to natural sites. Lumbricina community was dominated by endogeic earthworms. This is especially significant because the key role they play in edaphic processes since they modify both chemical and physical soil properties. It was found a clear decrease in Lumbricina abundance from a mean of 297 ind m-2 in natural sites to 70 ind m-2 in no-till and an increase in juveniles and diapause organisms in no-till in relation to the natural sites. These results were explained mainly by the high compaction and the low organic matter content. Furthermore, the possible negative influence of an intense use of agrotoxics, mainly associated to the increase in the number of juveniles and diapause organisms, is considered. It is concluded that in the studied region, soils would be threatened in relation to the maintaining of ecosystem functions which are the base of soil quality. The question arises about long-term sustainability of this crop system.

Palavras-chave : Soil macrofauna; Ecosystem engineers; Management; Soil Quality.

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