Paddy stubble poses major challenges in north India. The quantity of the crop straw and stubble is humongous and the window for disposing of it is too small. The article focuses on several existing initiatives and challenges in the management of crop residue for a clean and rejuvenating environment.
Stubble burning is intentionally setting fire to the straw that remains after crop harvest. Farmers in Punjab, Haryana, and some parts of Uttar Pradesh burn straws of paddy and wheat which has been cited as a major cause of air pollution in Delhi NCR. In late September and October month every year, Punjab and Haryana farmers burnt about 23 million tons of paddy straw in their field after the crop harvest considering stubble burning as a low-cost disposal practice and reducing the turnaround time between harvesting and preparing land for next (Wheat, mustard, gram, etc.).
Smoke from the straw burning produces a cloud of particulates that is visible from space and has been described as a "toxic cloud" in Delhi, resulting in declarations of an air-pollution emergency. For this, the NGT (National Green Tribunal) instituted a fine of Rs.2 lakhs on the Delhi Government for not submitting an action plan providing incentives and infrastructural assistance for the farmers to discourage them from burning crop residue preventing air pollution. When paddy crop is harvested by a combined harvester and thresher, the machine leaves behind a significant length of the crop as straw and stubble in the field which does not mix with soil.
This restricts farm operations in preparing the land and sowing subsequent crop wheat. Further, with a short window period of 10-15 days between paddy harvest and wheat sowing time, straw and stubble leftover land does not decompose and farmers consider its removal as an un-economic activity. The myopic behavior of farmers is to burn the paddy stubble in the field making it available for suitable farm operations. According to an estimate, farmers burned about 40 percent of stubble in Punjab and Haryana, out of the 35 million tons of paddy stubble produced last year.
In other parts of the country, farmers depending on the manual harvesting of crops, simply plough the land after harvesting and fill it with water for a few days that causing stubbles to decompose and enrich the soil with nutrients increasing its fertility for the next crop. Stubble burning apart from causing air pollution, it deteriorates the soil’s organic content, essential nutrients, and microbial activity – which altogether reduces the soil’s long-term productivity. Stubble burning has been prohibited or been discouraged in many countries, including China, the UK, and Australia.
Hazardous Effects
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The burning of stubble poses a serious threat to the air quality of the exposed environment. Air quality is considerably affected by agricultural burning due to the emission of aerosols and gaseous pollutants.
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Stubble burning strips the soil of the essential nutrients, i.e. nitrogen, phosphorus, and potassium (NPK) as well as other micro-nutrients. It also raises the soil temperature to about 42° centigrade displacing or killing the important microorganisms in the soil at a depth of about 2.5 cm. This generates an additional expense of regaining back the soil fertility through the application of fertilizer or compost.
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Emissions from stubble fires have a direct effect on weather and climate through the release of greenhouse gases such as carbon dioxide (CO2) and methane (CH4) which may potentially lead to global warming. It is reported about 10% of the total annual greenhouse gas emissions in the world are contributed by the agricultural sector.
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Apart from its effects on human health and the ecosystem, air pollution also affects the growth of a country's economy. In recent years, tourists' inflow in Delhi has decreased by about 25-30% due to the increase in the level of air pollution affecting the state economy.
This situation is leading to a double whammy. On one hand, by burning the crop residue, we are wasting this precious bio-mass which could be used either as cattle feed or as fuel. On the other hand, we are creating an environmental hazard of smog and turning the country into a gas chamber.
Management Suggestions
The main administrative bodies that regulate emissions and promote air quality in India are the Ministry of Environment, Forest and Climate Change (MoEF&CC), the Central Pollution Control Board (CPCB), and its subsidiaries at the state level, which are the Board's main administrative body’s coordinates to monitor and control environmental pollution. In India, although both the center and state governments have encouraged alternatives, for example by promoting the use of new machines and technologies, farmers have been reluctant to adopt them. Some of the key practices that have to be adopted for sustainable management of the crop residue by the farmers are as below:
Decomposing of the straw
The crop stubbles (if managed properly) could provide immense economic benefits to the famers and protect the environment from severe pollution.
Pusa Bio-Decomposer: The ICAR- Indian Agricultural Research Institute, Pusa has developed a ‘Pusa Decomposer’, a microbial capsule that can decompose straw in the field within 10-15 days of application. This works on stubble with soil and changes straw into manure by accelerating the decomposition process and making it easy to plough the soil.
As a result, Pusa decomposer may reduce the use and cost of fertilizers and could help increase the yield of the subsequent crop. It costs less than Rs 1,000 per acre. The Pusa decomposer was validated last year on the basmati paddy field of ICAR-IARI with promising results. At present, the Delhi government is working actively to solve the stubble issue and decided to provide the bio-decomposer to the farmers of adjoining states free of charge. The spraying will begin from the 11th of October in Narela and decide to spend 50 lakh as cost on the spraying of bio-decomposer solution.
Use as fodder
In India, it has been common practice to use paddy straw as feed for livestock. However, only 7 percent of rice and 45 percent of wheat stubble are been used for animal feed in Punjab. Some primary survey shows farmers use dry fodder in form of wheat husk and hay fodder as feed which costs Rs. 350-500 per quintal and if the paddy stubble is used, it costs just Rs. 100 per quintal. Northern states have a large number of unregistered gaushalas and also many government-sponsored cattle pools which are managed either by social organizations or not-for-profit groups. Most of the organizations managing gaushalas are primarily dependent on charity for feeding animals and sometimes face severe financial constraints. If they are trained to use paddy straw as dry fodder or with urea treatment or as silage, gaushalas will be able to bring down their expenses considerably. Therefore, the use of paddy stubble as animal fodder could be a sustainable and economically viable technique that, if efficiently used, could potentially mitigate the outdoor burning of stubble.
Bio-fuel production
Farm2Energy, a startup that claims to have found the solution to stubble burning, urges the farmers of Punjab to take a vow to not put paddy stubble on fire and convert it into biofuel instead. The organization offers a fully mechanized solution to paddy straw burning. It provides an integrated biomass supply solution for the advanced biofuels, biopower, and bio-based products industries, by processing paddy straw, corn stover, sugarcane trash, and wheat straw, and wheat silage.
There is wide scope for biofuels as tonnes of biomass is burnt leading to pollution and waste of valuable resources. Some of the existing initiatives and challenges for the biomass power sector is given below:
Biomass Depots:
It is essential to undertake on-field baling of stubble, aggregate bales in a depot, and enter into “bankable” agreements for supplies to Bio-Energy Plants. There should be fiscal incentives (capital subsidy from MNRE and interest subsidy from state governments) enabling green entrepreneurship.
Biomass Power Plants:
The Punjab Energy Development Agency (PEDA) has actively supported the biomass power sector, including provisioning for a high feed-in tariff of Rs.8/ KWh, but created capacity is relatively low. A sharp decline in solar and wind tariffs seems to act as constraint. The costs of establishing a year-round “bankable” supply chain for paddy straw bales is another deterrent.
Solid Biofuels:
These comprise briquettes and pellets. Briquettes are fired in industrial boilers or combustors but the demand in Punjab and Haryana is not high. Pellets can be co-fired in utility range boilers & NTPC has issued EOI’s for 5 million tonnes of pellets (at the rate of Rs.5500 to 6,000 per tonne) for firing in 17 of their power plants. However, investor response has been muted, as pellet production is capital intensive, coupled with high energy + O&M costs, apart from stubble bales costs, for year-round operations. It’s also a moot point as to whether NTPC can better deploy the Rs 2,000 crore annual incremental cost (for displacing Grade E coal by 5 million tonnes pellets).
Government Initiative for bio-oil and bio-methanol
Liquid biofuels include bioethanol, drop-in fuel, bio-oil, and bio-methanol. The focus of the government is on 2G ethanol. Oil manufacturing companies have announced 12 ethanol-based projects, which require a volume of 150,000 tonnes every year. The PM “JI-VAN” Pradhan Mantri (Jaiv Indhan- Vatavaran Anukool Fasal Awashesh Nivaran (scheme of the Ministry of Petroleum and Natural Gas provide for viability gap funding to enable it to meet the blending target of 20 percent by 2030. The Centre for High Technology (CHT), a technical body under the aegis of the Ministry of Petroleum and Natural Gas (MoP&NG) is implementing an agency for the scheme. However, given the high capital expenditure per lakh tonnes, the impact on stubble burning would be marginal.
Under the scheme, 12 commercial scales and 10 demonstration-scale second generation (2G) ethanol projects will be provided a Viability Gap Funding (VGF) support in two phases:
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Phase-I (2018-19 to 2022-23): wherein six commercial projects and five demonstration projects will be supported.
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Phase-II (2020-21 to 2023-24): wherein remaining six commercial projects and five demonstration projects will be supported.
It will more be benefitted to produce ethanol by the scheme beneficiaries and will be mandatorily supplied to Oil Marketing Companies (OMCs) to further enhance the blending percentage under EBP Programme.
Gaseous biofuels include producer gas, biogas, and green hydrogen. The current focus is on biogas upgraded to Bio-CNG, with co-product being composted. MoP&NG launch a scheme Sustainable Alternative towards Affordable Transportation (SATAT) in 2018, envisaged 5,000 plants, typically rated 3,000 tons/year bio-CNG, consuming about 33,000 tons/year of paddy stubble. OMC’s issued multiple Expressions of Interests (EoI) and signed a few hundred MoU’s. Under the scheme few of the enablers like an assured price for off-take of Bio-CNG (CBG) as compared to that offered for first-generation bioethanol or biodiesel. Therefore processing agriculture residues to bio-CNG and compost will benefit many more farmer households, with manifold collateral benefits that accrue from assured availability of sustainable energy/ mobility.
Other uses
Paddy straw is ideal for use as bedding for dairy animals. The compositing of straw with animal urine and dung produces high-quality fertilizer which could be another far-sighted approach for use of paddy straw. Also, the paddy straw could be used in making paper, cardboard, and packing material and hydroseeding (deliberated rice straw can be used in hydroseeding for erosion control). Farmers, who have already been sensitized to refrain from the burning residue, should be given options such as biomass generation. The geospatial techniques will help to identify areas where stubble burning is severe and encourage the installation of biomass plants at such locations.
Actions of the states
Uttar Pradesh Bio-Fuel Policy-2020: The proposed policy seeks to promote and incentivize the setting up of power generation plants based on paddy straws and also makes it mandatory for state-owned thermal stations to use agricultural residue as raw material with coal to fire the power plants. The state government will provide an annual grant of more than Rs 250 crore to the UPPCL to buy power that might be a little costlier than what it procures from other sources.
The draft policy clearly indicates that “setting up such power plants will stop 10 million tonnes (MT) of paddy straw from being burnt by farmers every year,” It is estimated that around 16 MT paddy straw is produced in the state, of which 4 MT is used by farmers themselves while the 12 MT paddy straw is burnt in the fields.
Another significant feature of the proposed policy is that it seeks to make it mandatory for the UP Rajya Vidyut Utpadan Nigam Ltd (UPRVUNL) to use agricultural residue in ‘pellet’ form as a raw material along with coal in its power plants to generate electricity.
The United States Trade Development Authority (USTDA) signed up to allocate a grant of $300,000-500,00 to an Indian engineering firm, “The Virgo Group”, to carry out a ‘scoping study’ for setting up a plant near Bhatinda that will convert the stubble from harvested rice fields into green biofuel.
Haryana:
Furthermore, the Haryana government spent Rs 1,300 crore to set up Custom Hiring Centres (CHCs), in order to help farmers manage straw by providing machinery at subsidized rates.
Conclusions
Increasing problems associated with crop stubble burning several initiatives for its proper management have been taken up. The various departments and institutions are promoting alternative uses of straw instead of burning. These include the use of rice residue as fodder, bio-fuels, bedding materials for cattle, paper and cardboard production, etc. Other uses include the incorporation of paddy straw in soil, energy technologies, and thermal combustion. An extensive awareness program is required to enlighten the farmers on the environmental and economic benefits of using alternative approaches in the management of crop stubble.
Authors Details
Arun Kumar is a Consultant at the Ministry of Petroleum and Natural Gas, (MoPNG) Government of India. Prabhat Kishore is a Scientist at ICAR-National Institute of Agricultural Economics and Policy Research (NIAP).
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