By – Dr. N. Munal Meitei
In Manipur, it’s high time for harvesting. Everywhere long spiral smog will be seeing from stubble burning. But due to much public awareness, a down-line of stubble burning is seen in the recent past. Stubble burning is not only illegal but it affects soil fertility, moisture, organic matter, microbial population and pollutes air, leading to the environmental degradation.
Stubble burning was not seen in the past. On the harvesting day itself, people used to make bundles & collect to heaps in their homesteads for fodder and other purposes. But now people hardly rear cattle and also due to lack of spaces, stubble is burnt to save labour, time and wages. People also have less knowledge about the benefits and determinants from the stubble burning. Thus, burning at the harvesting site itself is a common practice in the state and country.
Stubble burning reduces visibility, worsening air quality and endangering public health. While on stubble burning, the heat penetrate about 2 cm into the soil, elevating the temperature from 33.8°C to 42.2°C killing the beneficial bacteria, fungus and earthworm populations reducing soil fertility and increase erosion. Burning leads to drying up the soil, necessitating additional water for irrigation. Livestock, too, is impacted by crop burning. It has been found that milk production falls up to 50% during the two months of stubble burning.
A study on stubble burning, 84.5% of people were suffering from health problems due to the increased incidence of smog. 76.8% of people expressed eye irritation, 44.8% in the nose and 45.5% in throat irritation. Another study by the Institute for Social and Economic Change, Bengaluru, found that every year in rural Punjab people spends Rs 7.6 crore on treatment for ailments caused by stubble burning.
When stubble are scattered in the field during land preparation, they maintain soil’s nutrients and moisture. Every tons of stubble can increase soil nutrients; nitrogen 5.5 kg, phosphorus 2.3 kg, potassium 25 kg, sulfurs 1kg, besides organic carbon. Stubble can also be used as mulch to protect the roots of the plants from heat and cold and reduce the evaporation rate. They also prevent weeds to grow in the field.
Stubble burning decreases 38% soil nitrogen, 25% of phosphorus, 20% of potassium and 5-60% of sulfur. Incineration of agricultural residue contributes to 7% of total PM2.5 emissions in the country. While on stubble burning, the loss of nutrients per ha amounts to 339 kg Nitrogen (N‚ ), 6 kg Phosphorous (P), 140 kg Potassium (K) and 11 kg Sulphur(S) and many soil nutrients. Therefore with this rate, the total loss of nutrients in Manipur would be around 80.50 Mt. of N2, 1.42 Mt. of P, 33.22 Mt. K and 2.61 Mt. of Sulphur over and above many more important trace elements annually.
The amount of greenhouse gases emitted, when 1 ton of stubble is burnt are 2 kg of SO‚ , 60 kg CO, 4-7 kg CH4, 1460 kg of CO‚ , 3 kg particulate matters and 199 kg of ash. These are the pollutants that hamper the climate which hindered our seasonal rainfall every year. At the same time, if we could allow them to decompose without burning somewhere at a corner of the paddy field, then the soil could get back 156 – 170 kg Nitrogen, 10.15 – 20.75 kg Phosphorus, 66 – 70 kg Potassium and 5 – 5.70 kg Sulphur from the hay straw of 1.25 acre paddy field.
India’s rice production is about 8 tons/ha. Stubble burning showed a release of 11 tons of CO2-equivalent per ha of land. Our country produces 152.2 Mt. of rice and126.6 Mt. of stubble and 62.42% of them are burnt on the field annually. Haryana and Punjab contribute to 48% of the total stubble burning and releases 4,47,19,000 kilogram of total particulate matter (TPM) in the country increasing Air Quality Index up to 400 in Delhi on 27 October, 2024.
In absence of viable industries, agriculture is the main occupation in Manipur with about 80% of the total populations. Major parts of state’s employment up to 22.13% of the total work force are in agriculture sector with 12.98% areas used for cultivation and 52% of them are confined in the valley. The total cultivated area of about 289500 ha, which is about 82% of the gross crop areas are utilized for paddy cultivation.
A rough grain to straw ratio is about 1.0 to 0.8. In Manipur, the average rice yield is as high as 6.2 to 6.6 tons per ha (pari) and the subsequent stubble production is about 5.2 tons. Therefore, our state produced 15,05,400 tons of stubble annually. Thus, the total nutrients saving in Manipur would be around 113.6 Mt. of NPKS annually. While burning the heap up stubble near the trees along the roadside also kill the valuable plants.
Burning crop residue is a crime under Section 188 of the IPC and under the Air and Pollution Control Acts, 1981. National Green Tribunal directs all state governments to take up for coercive and punitive action to the violators of stubble burning. The penalties are; farmers with below 2 acres land while on burning have to pay Rs.2500, 2 to 5 acres for Rs.5000 and more than 5 acres for Rs.15000 as the environmental compensation. But in Manipur no such implementation is seen. But the farmers still burnt and prefer to pay the fines because paying fines save them more than to keep the NGT norms. Therefore, it is important to address their fundamental problems.
To save stubble, state government may plan to establish the industries which utilize the hay straw for various purposes, like producing ethanol, paper and packaging material, bio-char, compost, mushroom, fuel-briquette, fuel-pellets, pulp, animal-feed, eco-panel, erosion-control material and in-situ addition in conservation agriculture. The other method involves use of stubble for biomass energy plants to generate electricity. In Punjab, thirteen such plants producing 97.5 Megawatts have been established. In Manipur also, we may innovate for such power generating plants which will surely reduce the environmental problems and social impacts.
Rearing of cattle is another option, because stubble is a good fodder for cattle. Mushroom cultivation also known as protein cultivation is one of the most prospective eco-friendly practices to fight unemployment and malnutrition. Stubble which contains 41% cellulose, 14% lignin, 0.8% nitrogen, 0.25% P2O5, 0.3% K2O, 6% SiO‚ and with pH 6.9 is best for mushroom cultivation. The waste after mushroom cultivation is a good organic fertilizer.
While we allow the stubble to decompose in the field, it’s beneficial both for the farmers and the environment. Therefore let’s not burn the stubble but utilize it to uplift our rural economy and to save the environment for future generation.
(The author is Environmentalist, email-munall@yahoo.in)