Bescansa Miquel, PalomaVirto Quecedo, ÍñigoFernández Ugalde, OihaneImaz Gurruchaga, María JoséEnrique Martín, Alberto2018-10-252018-10-2520101687-7667 (Print)1687-7675 (Electronic)10.1155/2010/526934https://academica-e.unavarra.es/handle/2454/31211The behaviour of earthworms, their role in organic matter incorporation into the soil, and the influence of aridity in such processes in arid and semiarid regions have scarcely been studied. In this study, physico-chemical analyses of the casts and the surrounding no-till agricultural soils of three experimental sites representing an aridity gradient in Navarre (NW Spain) were done. The casts were formed by the activity of the only anecic species, Scherotheca gigas (Dug`es, 1828), ubiquitous in no-till soils in this region.We observed a significant depletion of clay and higher concentration of total organic C and labile C in the form of particulate organic matter (POM) in the casts as compared to the surrounding soil, suggesting selective ingestion of soil by S. gigas. This, together with the observation of increased concentration in POM with increasing aridity, suggests a major role of this species in the observed progressive gains of organic C stocks in no-till soils in the region.6 p.application/pdfeng© 2010 Paloma Bescansa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Scherotheca gigasParticulate organic matterNo-till soilsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccessAcceso abierto / Sarbide irekia