Effect of earthworm and plant residues for soil enrichment under agroforestry systems for north- east India

The experiment was conducted to highlight the effect of increasing concentration of macro and micro-nutrients in soil by using plant residues along with Indian epigeic earthworm (Perionyx excavatus). The soil (1kg) collected from the different plant based agroforestry systems viz., Arecanut, Banana, bamboo and colocasia and mixed with specific residues to form a substrate. The worms experienced variation in the mortality rate, weight, production, number of hatchlings and fertility of the substrates by rapid decomposition of the matters in all treatments. Available nutrients were maximum in the residue with cowdung treated substrates and available- P in non-residue treated soil. The microbial biomass in the soil was less whereas microbial activity was more in residue with cowdung treated soil. Reduction of C: N ratio due to mineralization brought out by the combined action of earthworms and microbes. It was observed that the organic manure and cowdung treated soil had high soil fertility.