EFFECTS OF EARTHWORM INTRODUCTION ON SOIL PROCESSES AND PLANT-GROWTH

We studied short-term effects of three selected earthworm species on s oil physical parameters and the production of Oryza sativa (rice), Ara chis hypogea (peanuts) and Zea mays (maize) in short-term pot experime nts at Lamto (Cote d'Ivoire). Millsonia anomala significantly compacte d the soil and decreased water infiltration whereas Chuniodrilus ziela e and Hyperiodrilus africanus had opposite effects, and the associatio n of C. zielae and Millsonia resulted in a moderate compaction. Plants had specific responses to earthworm activities. Arachis did not respo nd whereas maize had a much higher above ground production and decreas ed root production and rice produced more roots in the presence of wor ms. Earthworm species had different effects; the association of M. ano mala and C. zielae was the most efficient treatment whereas C. zielae alone, or H. africanus had little effect if any on plant production. ( C) 1997 Elsevier Science Ltd.