Crop Residue Management in India: Stubble Burning vs. Other Utilizations including Bioenergy

In recent studies, various reports reveal that stubble burning of crop residues in India generates nearly 150 million tons of carbon dioxide (CO2), more than 9 million tons of carbon monoxide (CO), a quarter-million tons of sulphur oxides (SOX), 1 million tons of particulate matter and more than half a million tons of black carbon. These contribute directly to environmental pollution, as well as the haze in the Indian capital, New Delhi, and the diminishing glaciers of the Himalayas. Although stubble burning crop residue is a crime under Section 188 of the Indian Penal Code (IPC) and the Air and Pollution Control Act (APCA) of 1981, a lack of implementation of these government acts has been witnessed across the country. Instead of burning, crop residues can be utilized in various alternative ways, including use as cattle feed, compost with manure, rural roofing, bioenergy, beverage production, packaging materials, wood, paper, and bioethanol, etc. This review article aims to present the current status of stubble-burning practices for disposal of crop residues in India and discuss several alternative methods for valorization of crop residues. Overall, this review article offers a solid understanding of the negative impacts of mismanagement of the crop residues via stubble burning in India and the other more promising management approaches including use for bioenergy, which, if widely employed, could not only reduce the environmental impacts of crop residue management, but generate additional value for the agricultural sector globally.

Energy use pattern of diversified cropping systems under different nutrient and crop residue management practices in Eastern Indo-Gangetic plain

Aim: Assessment of energy input output relationship, greenhouse gases emission and carbon footprint of diversified jute-rice cropping systems under different nutrients and crop residue management practices. Methodology: The inventory was prepared for all inputs required for crop cultivation and outputs of crops in cropping systems. These inputs and outputs were converted into energy by multiplying with energy equivalent coefficient and CO2 emission coefficient following standard procedure. Results: Jute-rice-baby corn cropping system recorded significantly higher net energy (324 GJ ha-1) and energy use efficiency (8.02). Among different nutrient and crop management (NCRM) practices, significantly higher energy output (336.9 GJ ha-1) and net energy (291.4 GJ ha-1) recorded 100% NPK with crop residue. The highest carbon footprint recorded with rice-rice (0.44 kg COe kg-1 economic yield) and the lowestwith jute-rice-pea (0.29 kg COe kg-1 economic yield) cropping system. Among different NCRM practices, higher carbon footprint was (0.38 kg COe kg-1 economic yield) recorded with 100% NPK with crop residue. Interpretation: The energy efficient and low input required cropping systems which include legume crops like garden pea and mungbean should be considered for cultivation for diversifying the existing rice-rice cropping system in Eastern India.

Sustainable Biowaste Management in Cereal Systems: A Review

Among the field crops, cereals being the staple food for humans and feed for cattle, occupy 50.8 per cent of the cultivated land and contribute 52.5 per cent of the body calories. Cereals are the good source of carbohydrate, minerals, and dietary fibre for humans and animals. With the ever growing human population the agricultural production and agri-wastes are increasing across the globe. In Asia, Africa and Latin America, near about 66, 21 and 13 per cent of total estimated 2,060 Tg of biomass are generated every year. Burning has been the cheapest, simplest, easiest and quickest way of eliminating bulky unwanted biomass in-situ before raising of the succeeding crop(s). Rice, wheat, sugarcane and maize constitute 24, 23, 5 and 48 per cent of the global burnt residues. Although killing of problematic weeds, insects, and pathogens, and addition of valuable plant nutrients are the very basic objectives of this anthropogenic post-harvest residue management strategy but it releases noxious gases into the atmosphere polluting air and contributing to the global warming. Shorter sowing windows very often compel the farmers to remove crop residues through burning, especially in absence of alternative options for its productive and profitable disposal. Rising labour cost and their seasonal scarcity sometimes also insist the farmers to burn crop residues. However, stringent punitive actions have yet failed to curb such open burning in many countries in absence of the farmers’ friendly and financially viable options of crop residue management. In this chapter, attempts have been made to elucidate various sustainable crop residue management strategies in cereal systems.

Nexus Between Crop Residue Burning, Bioeconomy and Sustainable Development Goals Over North-Western India

The crop residue burning in India particularly North-western India is responsible for air pollution episodes and public health concerns; greenhouse gases emissions and radiation imbalance; and declining soil organic matter and soil productivity. The objectives of this paper are to estimate the crop residue burning and emissions from crop residue burning, to recommend interventions in crop residue management and to propose a crop residue management-bioeconomy model incorporating strategies to sustainably manage the crop residues through interventions that enable waste valorization, food and nutritional security, farmers’ livelihood and sustainable agricultural production system. A national inventory on crop residue burning including the pollutant species was prepared using the IPCC methodology. The crop types included for the estimation are cereals, pulses, oilseeds, sugarcane, cotton, jute and Mesta. The total amount of crop residues generated and burned for the year 2017–18 was estimated at 516 million tonnes and 116 million tonnes respectively. It is estimated that 116.3 Tg of crop residues burning released about 176.1 Tg of CO2, 10 Tg of CO, 313.9 Gg of CH4, 8.14 Gg of N2O, 151.14 Gg of NH3, 813.8 Gg of NMVOC, 453.4 Gg of PM2.5, and 935.9 Gg of PM10. The emission estimates can be a proxy to prepare the national level inventory of air pollutant species from crop residue burning. The crop residue management (CRM) demands a transition from the traditional zone of CRM to bioeconomy zone of CRM, wherein the interventions aim at the sustainability of agroecosystem. The proposed bioeconomy model has a four-pronged strategy that includes smart agriculture practices, waste bioeconomy involving aspirational principles of bioeconomy, capacity building of stakeholders’ and proactive government policy. Sustainable agricultural bioeconomy provides ample opportunities to reduce crop residue burning, increase farmers’ livelihood and decarbonize the agricultural production. India’s efforts and policies can provide lessons for other agricultural regions having similar environmental constraints.