Microbial Composting And In Situ Degradation Of Paddy Straw

Ludhiana, April 22, 2015: According to the Microbiology and Soil Science experts of Punjab Agricultural University (PAU), the management of crop residues has become an important aspect of sustaining long-term fertility in cropping systems. Incorporation of crop residues can change microbial processes, which affect nutrient use efficiency by soil microorganisms.

Experts from PAU Departments of Microbiology and Soil Science are working on development of technology for microbial composting of paddy straw and its in situ degradation for the benefit of the farmers of the state. Traditionally, open-field burning of rice straw has been in practice to dispose off crop residues which results in air pollution, loss of 7-12 tonnes of nutrients per hectare and also loss of soil organic matter, cautioned Dr. Parampal Sahota, Head, Department of Microbiology. Further she said, there are currently few options for rice straw utilization because of its poor quality for forage, bioconversion and engineering applications.

She said that trials on the use of fungal cultures on paddy straw composting conducted at Research Farms of Microbiology and Soil Science, PAU, Ludhiana have demonstrated encouraging results. Trial running for 102 days, demonstrated the ability of Aspergillus terreus MTCC 11778 and Trichoderma hargianum MTCC 8230 to degrade paddy straw with an added advantage with respect to N,P,K content of the final compost, she said.

Elaborating further, she said that another trial on in situ degradation of paddy straw is in progress. A bacterial isolate identified as Pseudomonas sp. from naturally degrading paddy straw alongwith 5 per cent urea application degraded the paddy straw fast within 45 days compared with isolate from PUSA compost, she said.