Soil Microbial Activity and Biomass in Semiarid Agroforestry Systems Integrating Forage Cactus and Tree Legumes

Vegetation cover affects soil organic matter and activity of microorganisms. We investigated the intercropping effect forage cactus with tree legumes on microbial biomass in semi-arid tropic, state Pernambuco, Brazil. assessed following cropping systems: (i) Gliricidia sepium intercropped cv. IPA-Sertânia; (ii) Leucaena leucocephala (iii) Cactus IPA-Sertânia monoculture. Samples were collected during dry rainy seasons 0- to 0.10- 0.20-m layers at 0, 1.5, 3.0, 4.5 m a perpendicular gradient from legume rows. The responses determined: δ13C δ15N, C N, biomass, metabolic, microbial, mineralization quotient. δ15N varied distance trees. In season beginning season, systems showed similar values for C, activity, carbon, nitrogen biomass. presence end favored microbiota, which reduced loss C-CO2, no indication metabolic stress greater quotient relation