EDAPHIC MITES AND THEIR RESPONSE TO THE INCORPORATION OF ORGANIC MATTER FROM VARIOUS SPECIES OF FABACEAE INTO THE SOIL BENEATH COFFEE TREES

The aim of this study was to evaluate the presence and abundance of mites in the soil beneath cultivated coffee trees (Coffea arabica L.). In particular, we compared mite communities in three different soil environments: 1) native forest; 2) soils from underneath the coffee trees “under full sun” (i.e. areas that received no additional shade or organic treatment); 3) soils that incorporated organic matter from four leguminous windbreak plant species — acacia, Acacia mangium Wild.; pigeon pea, Cajanus cajan (L.) Millsp.; gliricidia, Gliricidia sepium (Jacq.) Walp.; and leucaena, Leucaena leucocephala (Lam.) de Wit. Sampling was conducted at the ends of the dry and rainy seasons, in São Sebastião do Paraíso, Minas Gerais, Brazil. Undisturbed soil samples were acquired using a cylinder and a Berlese-Tullgren funnel was used to extract the mites in the laboratory. A total of 1,014 mite specimens, assigned into 143 different species, were collected. The forest soil had the greatest richness and total abundance of edaphic mites, while the coffee plantation soils, enriched with acacia, had the lowest richness and abundance. The mite communities of treated soils were less than 18% similar to that of the forest soil. These results suggest that the substitution of native forests with cultivated systems can cause significant changes in the abundance, richness and structuring of edaphic mite communities, particularly of oribatid mites. Maintenance of mite communities should be one of the goals of agricultural practices, since these organisms are important for maintenance of biological cycles, especially for the decomposition of organic matter.