Soil meso and macrofauna under different no-till managements in a gradient of soil development in the Humid Pampa of Argentina.

BEDANO J.C.; AROLFO, R.; DOMÍNGUEZ, A.; VAQUERO, F. & L. WALL.

Coimbra

Congreso; XVI International Colloquium on Soil Zoology; 2012

The aim of this contribution was to evaluate the effect of the application of good agricultural practices (as defined by farmer?s organizations) under no‐till on soil meso and macrofauna and to assess whether this effect is different for soils with different degree of development. Three treatments were defined, replicated as blocks in three agricultural sites with different degree of soil development, situated across a transect in the Pampa region of Argentina: 1) Good agricultural practices under no‐till (GAP): intensive crop rotation (including cover crops),nutrient replacement, and minimized agrochemical use; 2) Bad agricultural practices under notill (BAP): high crop monoculture, low nutrient replacement and high agrochemical use; 3)Natural Environment (NE): a natural grassland adjacent to the cultivated plots. Multivariate analysis of all faunal groups showed a clear separation of sites according to management. The effect of GAP on soil fauna was strong in low development soils, moderate in medium development soils and weak in high development soils. As expected, soil fauna from NE was clearly different from that of the no‐till systems. The soil fauna communities of GAP were more similar to the NE communities than to the BAP, independent of the degree of soil development. Enchytraeids were associated to BAP soils, while most other meso and macrofaunal groups were more abundant in the natural soils. The results indicate that no‐till systems managed with the application of good agricultural practices support distinctive faunal communities, different from that of the no‐till system with monoculture, and highlight the potential of these organisms as bioindicators of agricultural soil management. A soil development constraint was evident, with more fragile soils reacting more positively to the application of good agricultural practices