Microbial Activity in Soil Cultivated with Different Summer Legumes in Coffee Crop

A field experiment was conducted for ten years in a sandy soil in the north part of the Parana State, Brazil. The soil samples were collected at 0-10 cm depth, both under the coffee canopy and in the inter row space between the coffee plants, in the following treatments: Control, Leucaena leucocephala, Crotalaria spectabilis, Crotalaria breviflora, Mucuna pruriens, Mucuna deeringiana, Arachis hypogaea and Vigna unguiculata. The legume crops influenced the microbial activity, both under the coffee canopy and in the inter row space. The cultivation of Leucaena leucocephala increased the microbial biomass C, N and P. Although L. leucocephala and Arachis hypogaea provided higher microbial biomass, the qCO(2) decreased by up to 50% under the coffee canopy and by about 25% in the inter row space. The soil microbial biomass was enriched in N and P due to green manure residue addition.