Unlocking the potential of crop residues: Profitable and eco-friendly solutions

India generates approximately 500 million tons (MT) of crop residues annually, with around 141 MT categorised as surplus, and 92 MT being burned. The improper management of these residues leads to severe environmental, health, and agricultural challenges. The burning of residues results in air pollution, loss of valuable nutrients, and a decline in soil quality.

Despite growing awareness, many farmers continue to burn residues due to a lack of viable alternatives and economic constraints. A recent paper by Gatkal et al., explores current trends, sustainable strategies, energy potential, and government interventions in crop residue management in India.

The problem of crop residue burning

Burning crop residues is a common yet hazardous practice in India, contributing to significant air pollution and greenhouse gas (GHG) emissions. The process results in the loss of essential soil nutrients, reduces microbial biomass, and adversely impacts soil fertility. Additionally, particulate matter released from burning leads to respiratory diseases, cardiovascular problems, and other health concerns.

Sustainable strategies for crop residue management

Several alternative methods can effectively replace residue burning and enhance soil health, crop productivity, and environmental sustainability.

• Residue retention and incorporation: Retaining crop residues on the field is crucial for soil health. This practice improves soil organic matter, boosts microbial activity, and reduces erosion. Conservation tillage techniques, like zero tillage and reduced tillage, further aid in moisture retention and overall soil health. By preventing topsoil loss and conserving moisture, retained residues lessen the need for irrigation.

• Mulching: Mulching crop residues offers several benefits, including regulating soil temperature, conserving moisture, and suppressing weed growth. This practice is particularly advantageous in semi-arid regions, where it reduces evaporation and improves soil fertility. Mulching also enhances microbial activity and helps retain essential soil nutrients, making it a cost-effective solution.

• Composting and biofertiliser production: Crop residues can be transformed into compost, enriching soil nutrients and decreasing reliance on chemical fertilisers. Using effective microorganisms (EM) accelerates decomposition, making nutrients more readily available to crops. Composting also reduces methane emissions from decomposing residues and presents a sustainable alternative to burning.

• Livestock feed: Certain crop residues, such as wheat and sugarcane tops, can be used as livestock fodder. Pre-treatment methods, like fermentation, improve the digestibility of these residues for cattle. This approach offers a dual benefit by managing residues while simultaneously supporting the livestock sector.

• Bioenergy production: Crop residues are valuable resources for bioenergy production, including biofuels, biogas, and electricity. Technologies like pyrolysis, gasification, and anaerobic digestion convert residues into energy-rich products such as biochar, bio-oil, and producer gas. This practice reduces dependence on fossil fuels and encourages the use of renewable energy sources, particularly in rural India.

• Briquetting: Densifying crop residues into briquettes provides a sustainable fuel alternative to coal and wood. Briquetting reduces transportation costs and improves the energy efficiency of biomass. These briquettes can be used for industrial heating, lessening the reliance on conventional fuels.

• Machinery for crop residue management: Several agricultural machines have been developed to incorporate crop residues into the soil, including the Happy Seeder, Rotavator, and Super Seeder. The Indian government is increasingly subsidising these machines to encourage sustainable residue management. Mechanising residue management allows farmers to adopt sustainable methods without increasing labour costs.

Government initiatives and policies

The Indian government has implemented several schemes to tackle residue burning and promote sustainable practices:

• National Policy for Management of Crop Residues (NPMCR): Encourages scientific approaches to residue management and emphasizes alternative uses of crop residues.

• Sub-Mission on Agricultural Mechanization (SMAM): Provides subsidies for purchasing residue management machinery, making mechanisation more accessible.

• National Bio-Energy Mission: Supports the conversion of agricultural waste into renewable energy sources like biofuels and biogas.

• State-level initiatives: Various state governments offer incentives to farmers adopting sustainable residue management practices, such as Punjab’s scheme for providing in-situ crop residue management equipment.

• Financial assistance: Government subsidies range from 50–80% for purchasing machinery like Happy Seeders and Super Seeders, making them more affordable for farmers.

Challenges in implementation

Despite the availability of sustainable alternatives, several challenges hinder effective crop residue management:

• High cost of machinery: Many small and marginal farmers cannot afford advanced machinery without government subsidies, making large-scale adoption difficult.

• Lack of awareness: Farmers often lack knowledge about the long-term benefits of sustainable residue management and prefer quick disposal methods like burning.

• Short crop cycle: The limited time between harvesting and sowing the next crop makes quick residue disposal a necessity, discouraging alternative methods.

• Policy implementation gaps: While policies exist, their execution at the grassroots level remains inconsistent, requiring stronger monitoring and enforcement mechanisms.

• Market and supply chain gaps: There is a lack of established markets for bio-briquettes and compost derived from crop residues, limiting their adoption.

• Technological and logistical constraints: Many sustainable residue management solutions require skilled labour and specific operational knowledge, which is often lacking in rural areas.

• Resistance to change: Traditional practices such as residue burning are deeply ingrained in farming communities, making behavioural change a challenge.

• Inadequate infrastructure: Lack of proper storage facilities, collection centers, and transportation options makes residue utilization difficult.

• Fragmented land holdings: Small landholdings prevent farmers from investing in large-scale machinery, leading to continued residue burning.

Future prospects and recommendations

• Strengthening infrastructure: Establishing collection centers, supply chains, and storage facilities to facilitate residue management.

• Developing incentive-based models: Providing financial incentives to farmers who adopt sustainable practices.

• Collaboration with private sector: Encouraging private investments in bioenergy projects and briquette production.

• Strengthening cooperative models: Promoting farmer cooperatives to enable shared access to machinery and resources.

• Real-time monitoring and policy enforcement: Implementing AI-based surveillance and stricter enforcement measures to curb burning.

• Educational campaigns and outreach programs: Conducting mass awareness campaigns through digital media, farmer training programs, and government outreach initiatives.

Sustainable crop residue management is crucial for India's agricultural and environmental well-being. By adopting eco-friendly alternatives, India can mitigate pollution, improve soil health, and harness the energy potential of crop residues. Strong policy support, technological advancements, and farmer participation are essential to ensuring a greener, healthier, and more productive agricultural sector. The integration of innovative technologies, financial incentives, and community-driven initiatives can lead to a long-term solution, making agriculture more resilient to environmental challenges.

The full paper can be accessed here