Effects of trefoil cover crop and earthworm inoculation on maize crop and soil organisms in Reunion Island

Traditional tree fallows have been abandoned on the western coast of the Re union Island because of the increasing need for cultivated land. Soil ferti lity is no longer restored and crop yields have decreased drastically. The leguminous plant, Lotus uliginosus (trefoil), used as a cover crop, has mad e possible the control of erosion, the restoration of soil macrofauna, espe cially earthworms, and the increase in crop yields. When trefoil was associ ated with earthworms (Amynthas corticis), the densities of maize, the yield s of maize stalk and dry matter, the yield of trefoil fodder dry matter, an d the biomass and respiratory activity of soil microflora were considerably increased. The combined effects of their association led to a significant decrease in populations of the plant-parasitic nematode, Pratylenchus vulnu s in maize roots, and in the population of borers. Some soil chemical featu res were modified.