Bacteria, a microscopic organism, may be the solution to a gigantic problem that has long challenged the state government and the agriculture department — to stop the open burning of paddy straw after harvesting.
Punjab Agricultural University (PAU) has come out with a small answer. Its microbiologists and soil scientists have done successful trials on microbial composting and on-site degradation of crop residue, using bacteria. Traditionally, open-field burning of paddy straw is the practice to clear the fields for the next crop, which pollutes the air and robs each hectare of soil of 7 to 12 tonnes of nutrients and organic matter.
The government has tried its best but failed to educate farmers about the harms to the soil, air, human, and cattle health. For them, burning straw is the easiest and the cheapest way of getting rid of it. Suggestions have been made to make laws to halt this practice but its political implications have discouraged the governments.
Increasing the options
Speaking on the issue over telephone, PAU microbiology department head Parampal Sahota said the rice-straw bioconversion engineering options were limited, so far, because of the poor quality of forage.
“The management of crop residues is important for sustaining long-term fertility in cropping systems. The Incorporation of these residues can change microbial processes that affect nutrient-use efficiency,” she said, adding: “Trials on the use of fungal cultures on paddy straw composting have demonstrated encouraging results. These were conducted on the PAU research farms in Ludhiana over 102 days.”
The trials demonstrated the ability of Aspergillus terreus MTCC 11778 and Trichoderma hargianum MTCC 8230 bacteria to degrade paddy straw with an added advantage with respect to the NPK (nitrogen, phosphate, potassium) content of the final compost. Another trial on in-situ (on-site) degradation of paddy straw is in progress. Pseudomonas, a bacterial isolate from naturally degrading paddy straw, with just 5% urea application degraded the paddy straw within 45 days, faster than any other form of compost.
Time-saving and effective
The degradation helped tackle the post-harvest residue. After straw is shortened with the help of Happy Seeder, it is treated with the bacterial isolate. There is no need to gather the straw in one large heap for treatment. “In-situ degradation is time-saving and effective,” said the PAU scientist.
The university’s microbiologists hope that the method will put to end to the menace of straw burning. It is likely to be applied in the paddy-harvesting season this year.