Efficacy of ligno-cellulolytic microbial consortia on biodegradation of paddy residues and its effect on biological properties of soil

Abstract

In rice cultivation, rice straw is produced as a by products, which is composed largely of ligno-cellulolytic components which makes it high C:N ratio. Ligno-cellulolytic fungus, bacteria and actinomycetes can be used as potential agents for rapid composting of bulky rice residues. Four species of fungus (Aspergillus spp.) bacteria (Bacillus spp.) and actinomycetes (Streptomyces spp.) were used for the decomposition of paddy straw both individually as well as in various combinations for analyzing their potential for the degradation of lignin and cellulose content of paddy straw. Among eight treatments, the microbial consortia (Aspergillus spp. + Bacillus spp. + Streptomyces spp.) were showed maximum activity. Inoculation of these ligno-cellulolytic microbial consortia in rice residues accelerated the process of decomposition when compared to control. A significant increase was also observed in total NPK content. Soil microbial biomass carbon (242.91mg CO2-C kg-1) and nitrogen and particulate organic carbon (1.34 g kg-1) was maximum in soil + paddy straw + Aspergillus spp.+ Bacillus spp.+ Streptomyces spp. treatments. Hence we conclude that combination of ligno-cellulolytic microbial consortia viz., Aspergillus spp. + Bacillus spp.+ Streptomyces spp. can be recommended for the degradation of rice residues and enhance the soil properties.