EARTHWORMS AS USEFUL BIOINDICATORS OF AGROECOSYSTEM SUSTAINABILITY INORCHARDS AND VINEYARDS WITH DIFFERENT INPUTS

Earthworm communities were studied in 72 different agroecosystems incl uding vineyards and three types of orchards: apple, peach and kiwi. Or chards had different agricultural inputs, in particular copper (namely , copper sulphate applied as fungicide), and soil cultivation. Heavy m etals were analyzed together with other soil parameters (nutrients, ba cteria and fungi). No differences were detected regarding microorganis ms in orchards subjected to different agricultural practices. Copper c oncentration was higher in vineyards. Total earthworm abundance and bi omass were severely reduced both by copper input and soil tillage. Ind ividual species gave different responses to agricultural practices. Ap orrectodea caliginosa was negatively affected by both copper concentra tion and soil cultivation, while Allolobophora chlorotica was negative ly affected only by copper input. Lumbricus rubellus and Lumbricus cas taneus were nearly absent in tilled orchards but apparently they were not much affected by copper input. Octodrilus lissaensis and Octodrilu s pseudocomplanatus did not seem to be reduced by copper input and soi l tillage. Species number and biomass were reduced both by tillage and copper input. Negative effects of tillage and fungicide residues (Cu, Zn) are clear enough factors to promote more extensive use of earthwo rms as reliable bioindicators in the rural landscape. (C) 1998 Elsevie r Science B.V.