Producing energy from rice straw: an alternative to burning crop residues in India


When the crops are harvested and the rice is threshed, what happens to the left overs of these valuable crops? Crop residues that are often just burnt can be used for various purposes including feeding livestock and producing energy. They can also be added to soil to improve its organic content.

Manas Puri, an expert in Sustainable Energy in agriculture working with FAO explained:

“The amount of crop residues that are currently being burnt as waste is double damage – polluting our environment and eliminating a valuable material that can be used in a multitude of ways.”

He added that the Government of India has been looking at options to improve the crop residue management process to reduce the burning and to use the residues more efficiently.

Identifying both environmentally sustainable and economically viable end uses is vital. FAO has the tools to support India to do this through the design and implementation of sustainable bioenergy strategies. 

Around 304 million people in India have no access to electricity and around 500 million people depend on traditional biomass - wood fuel and agricultural by-products for cooking.

Mr. Puri described how “many farmers burn the residues because it’s an easy option even though it’s a lost opportunity to diversify income generating activities and it causes strong air pollution.”  

Air pollution in India’s National Capital Region (NCR) has been a major concern over the last few years. A recent study by the Indian Institute of Technology, Kanpur (IIT-K) identified crop residue burning as one of the main sources of deteriorating air quality in NCR during the months of October and November.

Burning crop residues to quickly and cheaply dispose of them is a widespread practice, especially in the states surrounding the capital, Delhi. According to estimates from the National Institution for Transforming India (NITI Aayog), roughly 39 million tonnes of paddy straw is burnt annually in Haryana, Rajasthan, Uttar Pradesh and Punjab, resulting in severe air pollution spikes in these states and the capital.  

For farmers, it is a way to clear the fields quickly in the two to three weeks between cropping seasons. In terms of soil health, the burning of biomass is detrimental, besides loss of soil organic carbon, in each tonne of rice straw burnt, 5.5 kg Nitrogen, 2.3 kg phosphorus, 25 kg potassium and 1.2 kg of Sulphur are potentially lost. These are all essential nutrients to retain soil fertility over time. In addition, heat from the burning residues can kill soil biota which is essential for the development of crop roots.

India’s Cabinet Committee on Economic Affairs recently allotted 11.52 billion Indian Rupees (169 million US Dollars) to be spent over two years to subsidize agricultural machinery to turn rice straw into mulch – an organic material that provides necessary nutrients and retains soil moisture for crops.  

“This is a commitment and has obvious benefits for the soil but using all the rice straw currently burnt on site in Punjab and Haryana, around 20 million tonnes, could be a major challenge” explained Mr. Puri.

India also has ambitious renewable energy targets, outlined in both its energy policy as well as its NDCs, India aims to increase its Renewable Energy capacity from 35 GW in 2015 to 175 GW by 2022. This target includes a bioenergy specific target of 10 GW.

While energy production from residues is a viable option, it is important to ensure that enough of the residues like straw are still available for day-to-day use; bedding for livestock or for traditional handicrafts and basket-making.

FAOs Bioenergy and Food Security approach (BEFS) Rapid Appraisal consists of a set of easily applicable user-friendly tools which allow countries to get an initial indication of their sustainable bioenergy potential and of the associated opportunities, risks and trade-offs. The whole bioenergy pathway is considered, from an assessment of feedstock availability to energy end use options. The tools can be customized and adapted to specific country requirements, such as crop burning in India. Mr. Puri concluded that

“Not taking this opportunity to produce sustainable energy from crop residues could represent a loss for India in general. Producing green energy from residues contributes to meeting the country’s Nationally Determined Contribution targets and combatting climate change.”