PUSA spray: a breakthrough to reduce air pollution in Delhi NCR

Dr varsha Gayatonde and Dr PrudhviRaj Vennela

2021-11-12 15:12:03

Credit: pixabay.com

Credit: pixabay.com

Bengaluru-based firm “nurture.farm” is providing technology to aid farmers to spray decomposers over an unprecedented 5 lakh acres which proves to be a boon to the National Capital Region (NCR). The firm is offering a microbial bioenzyme “Boom spray” developed by Indian Agriculture Research Institute (IARI) to help farmers across India to dispose stubble (crop residue) on their farms responsibly. The company is giving free service to farmers where spraying the bioenzyme, named “Pusa Decomposer”, and gets converted into manure, thereby improving the quality of soil. A technology-led solutions provider for sustainable agriculture, has signed up with more than 25,000 farmers, mostly in Punjab and Haryana, covering an area of over 5,00,000 acres. Thanks to IARI and nurture.farm for this innovative solution to poor air quality index.

The “boom sprayer” is a hybrid between a tractor and an autobot from the Transformers; its has two 20-feet booms that spread out like outstretched wings. On them are equally spaced nozzles that spray bio-decomposers on the freshly harvested rice field where about 700 of these machines will be at work across 5 lakh acres in Punjab and Haryana. The decomposers are a powder (earlier introduced as capsules) mixed in water meant to accelerate the process of turning rice stubble into compost. Untreated rice straw takes 4-8 weeks to disintegrate which is too long for the average farmer to wait to be able to sow the winter wheat crop. The other option is to employ farm labour, who will cut the stalk and pile it into bundles, but that’s expensive and unaffordable for more than 95% of the farmers. Here, by not alighting the fields, carbon as well as essential soil-micronutrients will be retained. After spraying, the soil needs to be turned over and irrigated. When done correctly — spraying, turning the soil over and irrigating it for four days. As per the company claim, with the boom sprayer, an acre can be sprayed in 7 minutes whereas manually it takes half a day.

The Delhi government is bearing the cost of spray and has appealed to all the States to help their farmers in decomposing the stubble by bearing the entire cost of spraying the bio-decomposer. From making the solution to spraying in the field, the entire process costs less than ?1,000 per acre. The Commission for Air Quality Management (CAQM) too has ordered all States to use the bio-decomposer solution after the Delhi government submitted the third-party audit report. The Water and power consultancies Ltd. (WAPCOS), a Central government agency, had conducted the third-party audit of the impact of spraying the bio-decomposer on the stubble.  The solution has been prepared in collaboration with Indian Agricultural Research Institute, Pusa, and the government is spending about ?50 lakh from making the solution to spraying in the fields. Several state governments viz., Haryana has reportedly allocated ?200 crore to disincentivise farmers from crop burning. Uttar Pradesh will be spraying a decomposer using a cow dung manure over 1 million acres. Haryana in 1 lakh acres, Punjab 5 lakh acres and Delhi in 4,000 acres under paddy.

Stubble burning problem at Delhi NCR: Stubble burning is a term that is frequently seen in the news is one of the major causes of winter pollution in northern India.   Every year, burning rice paddy stubble on around 5.7 million acres of land contributes to polluting the air and smog formation (smoke+fog). The burning of stubble also impacts the quality of soil as the process kills nutrients and beneficial microbes. Flora and fauna are also destroyed in the fire. Stubble burning emits fine particulate matter, an air pollutant that is a concern for people’s health when levels in the air are high; the particles can get trapped inside the lungs and increase the risk of lung cancer by 36%. Around 75% of Indian farmers own land, which spans a hectare or less. They are aware of the negative implications of crop burning, but lack of access to the latest technology, and farm mechanisation pushes them to burn stubble. Any delay in disposing stubble directly affects their next crop cycle, which has a domino effect on their yield and ultimately their income.

According to a study, the burning of crop residue released about 149 million tonnes of carbon dioxide, more than 9 million tonnes of carbon monoxide, 0.25 million tonnes of oxides of sulphur (SOX), 1.28 million tonnes of particulate matter (PM) and 0.07 million tonnes of black carbon. As evident, it contributes to a lot of greenhouse gas emissions. As per the reports, it could also aggravate the conditions leading to the spread of COVID-19. In particular, the stubble burning across Punjab and Haryana contributes to the winter haze in Delhi where about 40% of the near-surface particulate matter can be attributed to the stubble burning. The practice  can also cause an increase in ‘enemy’ pests because, during the burning, many microorganisms in the air are killed. The loss of these organisms leads to an increase in the pests, in turn, causing increased diseases in crops.

Why Stubble Burning?

Stubble burning is the intentional burning or setting on fire of crop residue to remove them from the field in order to sow the next crop. Leaving stubble on the field will invite termites and other pests which can damage the subsequent crop. In Punjab and Haryana, farmers burn the stubble/ chaff left after the rice harvest so that the field may be readied for the next Rabi crop like wheat. In these areas, it begins around October, the same time at which the southwest monsoon withdraws. Section 188 of the Indian Penal Code (IPC) makes stubble burning a crime. Additionally, it was notified as an offence under the Air (Prevention and Control of Pollution) Act, 1981.

Stubble burning is an age old practice?

In the 1960s, as part of the Green Revolution, farmers in Punjab and Haryana were encouraged to do wheat-paddy crop rotation to make India self-reliant in grains production. As a result and because of assured procurement of rice and subsidies, rice acreage increased.  The Punjab Preservation of Subsoil Water Act (2009) made it mandatory for farmers to transplant paddy late during the Kharif season to prevent loss of water. This gives the farmers very little time between harvesting the rice crop and preparing the field for the next winter crop. Hence, stubble burning is a quick, cheap and easy way to clear the field of any rice chaff residue. One reason for the large quantity of rice stubble left behind after harvesting is the increased modernisation and mechanisation of agriculture. Mechanised harvesting extracts the rice grains only leaving behind huge residue. Manual harvesting is not an option for farmers because of the huge labour charges and the increased time taken. Earlier, the stubble used to be used by farmers as hay to keep animals or homes warm, and even for cooking. However, these uses of stubble have now become outdated. Also, rice straw is not considered suitable as fodder for animals because of its high silica content. Despite the Punjab government making available tractor-mounted ‘happy seeders’ to cut down the rice stubble and sow wheat seeds simultaneously, many farmers find the prices of these machines or their rents prohibitive. Also, stubble burning requires only a matchbox whereas the adoption of these machines incurs additional costs for the farmers. Apart from harmful effects the practice has some advantages as it is a cheapest and quickest way to deal with crop waste, destroys weeds including those that are resistant to herbicides. It kills other pests also, such as slugs and decrease nitrogen tie-up.

Other alternatives stubble burning problem: Incentivise farmers for not burning the stubble and provide economic value for the crop residue. The stubble can be converted into fodder or organic fertilizer or fuel. The government should also subsidise or incentivise the industries that are engaged in converting stubble into economically viable products. Efforts should be made to improve the combine harvester that farmers use to harvest the crop. The current machine used leaves behind a huge residue. Improvement should be made in the technology used in such machines so that minimal residue is left behind. Encouraging and incentivising the farmers to go for early paddy, so as to give them enough time to harvest and thereafter prepare their fields for the next Rabi crop. Sowing alternate crops and shift them away in the long run from paddy to maize, fruits, vegetables and cotton.

The high-grade organic fertilizers can be prepared by mixing the stubble with cow dung and some natural enzymes.  This has been initiated by the Chhattisgarh government which has set up gauthans in many villages. In these, gauthans, farmers bring their stubble to a ‘gauthan’ where it is mixed with cow dung and enzymes to obtain organic fertilizer. This initiative also provides employment to the rural youth. A lot of nitrogen, potassium, sulphur, phosphorous as well as organic carbon are destroyed every year on account of stubble burning. They should ideally be used to make organic manure. This will also reduce the dependency and use of chemical fertilizers. The straw can also be used in electricity generation.

The government should penalise farmers that indulge in stubble burning. The government can also consider reinterpreting the MSP scheme to disallow the benefits of the scheme to farmers who practice crop residue burning. The government has to increase monetary incentives for avoiding and also make machines that counter stubble burning an affordable, viable and accessible option and offering attractive alternatives for farmers. Eminent agricultural scientist M.S. Swaminathan has suggested that the state governments could set up ‘Rice Bio Parks’, where farmers could convert stubble into products including paper, cardboard and animal feed.