With increases in food production crop residues are also increasing. It is estimated that about 500 Mt of crop residues are generated in India annually. Burning crop residue has caught the nation’s attention, not only for wasting a resource which has a potential to improve farmers income, but also for polluting the environment, affecting the health of the citizens.
While crop residues have multiple uses like serving as soil mulching, bio-manure/compost, thatching for rural homes, bio-gas generation, livestock feed, bedding material for animals, etc., yet it is being burnt for various reasons in recent years, for example shortage of human labour, high cost of removing the crop residue from the field and mechanized harvesting of crops. The problem is, however, more severe in the irrigated agriculture, particularly in the mechanized rice-wheat system of north west India.
It is estimated that burning of one tonne of rice straw accounts for loss of 5.5 kg Nitrogen, 2.3kg Phosphorus, 25 kg potassium and 1.2 kg sulphur besides, organic carbon. Generally crop residues of different crops contain 80% of Nitrogen (N), 25% of Phosphorus (P), 50% of Sulphur (S) and 20% of Potassium(K). This shows the potential of the crop residues to improve soil fertility when ploughed back to the soil. When managed efficiently, use of crop residues also leads to many other benefits, like improved farm incomes and safe environment. This issue focuses on those farmers experiences who have successfully recycled farm wastes to their benefit.
Small family farms are designed for utilizing the resources to the maximum and appropriately, by integrating various components on the farm, to meet the family needs and income. Such recycled farms transform into eco friendly farms, multiplying the beneficial effects. Recycling of farm resources reduces input costs, enables low reliance on external inputs, improves quality of produce and ultimately ensures farm sustainability under climate change conditions. Such farms have been simply handed over by generations as a way of life.
Traditionally women farmers in small homesteads are especially good and innovative at recycling of farm resources. They utilize the farm residues as fuel wood or for nutrition gardens. Mrs. Usha from Pathiyor Panchayat in Kerala uses cowdung slurry in producing vermicompost, which is applied to her kitchen garden (Anithakumari.P and Induja. S). Laxmi Bai from Borgi village in Karnataka, made Panchagavya by mixing nine different ingredients easily available in her kitchen and farm like. This served as immunity booster for cattle and raised the milk yield, when added in their feed. (Jasbir Sandhu and Shivananda Matapati )
Farmers in Khunti and Ranchi districts in Jharkhand are using biomass as mulch for fruit trees. Bhoomi Sudha (Tephrosia candida) has been identified as a biomass yielding plant and has been included in the fruit cropping system. Recycling of biomass as mulch in plant basins was found to result in significant increase in soil moisture, soil nutrients and organic matter content which is reflected in terms of increased plant vigour and yield. (Bikash Das, Pradip Kumar Sarkar). Also, planting of leguminous plants with deep root systems to enhance the nutrient uptake from deeper soil layers, combined with N inputs from N fixation, is considered to be one of the most effective ways of improving nutrient cycling onfarm.
Innovative farmers like Ramesh Chander Dagar have multiple uses for farm wastes. He uses the agro wastes for his dairy, produces biogas from the farm wastes and also uses for composting. Besides, Dagar’s farm pond is the site of yet another innovative cycle. His farm pond collects rainwater, which is used in the dairy to wash buffaloes. “I have also introduced fish into the pond; that fetches me about Rs 30,000 per annum. So, I am not only recharging groundwater, but also making money out of it,” explains Ramesh Chander Dagar. (Nidhi Jamwal). Mr. Krishan Rai from Nepal too is an exemplary farmer. Human and animal excretions make up the fertilizer bank of Mr Rai, which is converted to vermi compost, vermic tea, fertilizer capsules and liquid fertilizers while powering bio-gas as well. In this way, every kind of organic waste is efficiently converted into powerful fertilizers completing the bio-cycle with optimum utilization of available resource.
Institutions too have played their role in helping farmers recycle their agro wastes. For instance, Appropriate Rural Technology Institute (ARTI), through their experiments, brought out many new insights in the technology of biogas production. While dispelling the myth that cowdung is essential for biogas production, ARTI’s experiments concluded that pure carbohydrates devoid of any nitrogen also yielded biogas in ample quantities, indicating that crop residues which contain primarily cellulose could be converted to biogas. (Anand Karve). Mainstream institution like ICAR-CPCRI under the Farmer First Program (FFP) evolved a practical model of using cow dung slurry and cow urine in vermicomposting units, utilizing coconut organic residues and farm wastes. (Anithakumari.P and Induja. S)
Crop residues, a large portion of which go waste, if recycled through microbial processes, can add to a lot of organic carbon. The compost thus produced is further enriched and fortified with the desired beneficial microbial consortium of nitrogen fixers, phosphate solubilizers, potassium and zinc mobilizers, iron chelators and phytohormone producers by simply incubating it over 15 to 20 days in the field. ICAR has demonstrated this bioconversion method among more than 3500 farmers from 30 villages in four districts of Eastern Uttar Pradesh, with good results.(D P Singh..)
With all its positive results, if resource recycling has to be adopted by large number of farmers, it has to be backed by government support. Widespread awareness and capacity building for farmers and change agents is necessary. For example, The Learning Exchange on AgroEcology to Srilanka, organized during March 2018, by Pesticide Action Network Asia and the Pacific, for its partners in South Asia, has provided new ideas and practical learning on effective recycling and management of farm waste.(Suresh Kanna). Beyond awareness, incentives for recycling farm wastes and support in terms of technology for optimum utilization of crop residues and finance for adopting the technologies, for example, setting up biogas unit, are essential. Also, policies to discourage crop waste burning are also crucial.