Agricultural Waste Management Through Crop Residue Management: Challenges, Solutions, and Technological Advancements

1. Introduction

Agricultural wastes are the leftover materials produced during the cultivation and processing of agricultural items such as fruits, vegetables, meat, dairy products, and crops. These residues are wastes of agricultural production and processing, containing chemicals that may be helpful to people but are not economically valuable enough to collect transport, and process for use. The nature of agricultural waste varies according to the agricultural activity and can be liquids, slurries, or solids. Agro-waste, also known as animal waste (such as manure and animal carcasses), food processing waste (with only 20 percent of maize being canned and the remaining 80 percent becoming waste), crop waste (such as corn stalks, sugarcane bagasse, and discarded fruits, vegetables, and pruning), and hazardous and toxic agricultural waste (including pesticides, insecticides, and herbicides). Although precise statistics are difficult, agricultural waste is widely acknowledged to account for a sizable proportion of overall waste generated in developed countries. As agricultural production grows, so does the amount of livestock waste, agricultural waste, and agro-industry byproducts. As developing countries continue to intensify their farming practices, there is a significant increase in global agricultural waste. It is estimated that roughly 998 million tonnes of agricultural waste are produced annually worldwide (Agamuthu et al., 2009).

Rising food consumption in developing countries has led to tremendous growth in global food production. Rice-wheat farming systems cover 13 million hectares in South Asia (India, Pakistan, Nepal, Bangladesh, and Bhutan). Rice-wheat (RW) farming systems produce around 20 per cent of overall cereal production and 40 per cent of wheat production in India (Chaudhary et al., 2024). The Indo-Gangetic Plains (IGPs) include more than 85 per cent of South Asia's RW system. India's IGPs account for around 20 per cent of the country's total geographical area (329 Mha) and approximately 27 per cent of the country's net cultivated land, producing almost 50 per cent of total food consumption (Das et al., 2024).

The continuous rice-wheat cropping system, intensive tillage for both crops, crop residue (CR) removal, and use of excessive water and chemicals have resulted in environmental and ecological imbalance. The CR is made up of plant materials that remain after crops have been harvested and threshed. These residues were once thought to be waste, but with more knowledge and research, it is becoming clear that they are not waste, but rather an important natural resource. CR recycling could be used to convert surplus farm waste into useful materials. These items can help with nutrient replenishment, soil fertility enhancement, and ecological balance, all of which improve crop yield. Many farmers use wheat straw as animal feed, but rice straw remains a problem due to its high silica concentration (Padmakumar et al., 2024).