Influence of alley copping system on AM fungi, microbial biomass C and yield of finger millet, peanut and pigeon pea

An experiment was carried out to study the effect of spacing of tree species on native AM fungi and microbial biomass C in the soil in an alley cropping system. The treatments comprised of 3 spacings (4, 8 and 12 m) as main plots, two perennial leguminous plant species ( Gliricidia — Gliricidia sepium and Leucaena — Leucaena leucocephala) as subplots and three field crops (finger millet— Eleusine coracana , peanut— Arachis hypogea and pigeonpea— Cajanus cajan ) as sub–sub plot treatments laid out in a split–split plot design with four replications. Growing finger millet, pigeonpea and peanut in between Leucaena supported mycorrhizal parameters like spore numbers and infective propagules of AM fungi in the rhizospheric soil compared to those grown in between Gliricidia . The microbial biomass C in soil was more in all the three alleyed crops grown in between Gliricidia. Spacing of 12 m between trees supported all the microbial parameters studied (except mycorrhizal spore numbers) and also the yield of finger millet, pigeonpea and peanut. Growing finger millet as an alley crop in between Gliricidia spaced 12 m apart considerably improved the yield of finger millet.