Composting of rice husk using different inocula and analysis of compost quality

Recycling of crop residues in agriculture through production of compost brings the much needed organic matter to the soils. Rice husk is an agricultural residue abundantly available in rice producing countries. It contains high amounts of cellulose and lignin. The composting of rice husk with different microbial consortia viz 2 per cent lignocellulolytic fungus (Aspergillus sp), 2 per cent lignocellulolytic bacteria (Enhydrobacter aerosaccus ACCA2) and earthworm (Eisenia foetida) alone and in combinations was done for a period of 3 months during summer period in south India. The nutrient dynamics during the period of composting was monitored at frequent intervals. At 90 days of composting, C-N ratio of compostable material decreased from 88: 1 to 17: 1 in the treatment which received 2 per cent lignocellulolytic fungus. The analytical results showed that rice husk composted with lignocellulolytic fungus (LCF) recorded the maximum nutrient content of 1.10 per cent of N, 0.96 per cent of P and 1.24 per cent of K compared to other methods of composting. The raw rice husk and composted rice husk were examined through scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) and significant structural and chemical changes were observed.