Sustainable Livestock Waste Management Practices in India
The manure generated by animal production is currently receiving a great deal of attention in the water quality arena. While manure generated by livestock have historically been returned to the soil to improve its fertility, the concentration of large numbers of confined animals and increasing urban encroachment into agricultural areas have created several concerns.
In order to stay economically competitive, most commercial livestock and dairy production operations have found it necessary to increase the number of animals utilizing the same land base. More manure is generated than can be safely applied to the soil. Consequently, waste treatment technologies must be upgraded.
Adoption of animal waste best management practices can reduce the transport of nutrients and pathogens from farms, contributing to improved water quality. Improved management and utilization of animal wastes can occur through proper collection, storage, proper land application, and composting. Such strategies can benefit farmers by reducing disposal problems and reliance on commercial fertilizers, as well as improving water retention and fertility of soils.
A common practice in rural areas of India is the use of animal waste as a source of biogas to be used primarily for cooking purposes. The animal waste is usually collected at the end of the day, shaped into cakes and then left under the sun for drying for at least 15 days in the summer and 30 days in winter on the walls of the houses. This act does not appeal to the eyes, is unhygienic and may the spread of diseases in addition to the practice being environmentally unfriendly at the same time. According to World Health Organization, about 1.6 million people, mostly women and children, die each year due to cooking and heating with wood, dung, coal or crop waste [1]. When it rains these cakes are usually destroyed which means there may not be a cooking gas source to prepare the food. Apart from loss of the heat source, the washed away cakes move towards the nearby lake or river and contaminate the water body. This contamination has major impacts on human health as the water bodies are normally used directly without any treatment. In addition to the cakes, twigs were also used to ignite the fire and then spread it to the cakes to maintain the temperature required for cooking. Besides supplying energy and manure, biogas technology provides an excellent opportunity for mitigation of greenhouse gas (GHG) emission and reducing global warming through substituting firewood for cooking, kerosene for lighting and cooking and chemical fertilizers [2]. A study produced by AGAMA energy in 2008 concluded that at least 9.5% of South Africa’s rural houses are viable to produce biogas and take part in a rural biogas program. In other words, 310,000 houses in South Africa produce enough plant or animal waste to feed and run a bio digester [3]. In addition, UAE can also create biogas using animal waste. UAE has a great number of camel and sheep on its land. Production of biogas requires anaerobic condition where methanogenic bacteria can act on plant waste or animal dung. Biogas is a mixture of gases and primarily consists of 50-70% methane (CH4), 30-40% carbon dioxide (CO2), 5- 10% hydrogen (H2) with low concentrations of nitrogen (N2), traces of water vapor and hydrogen sulfide (H2 S). The methane production usually involves three stages, as follows: (1) Hydrolysis – breaking down of large molecules to sugars, amino acids and fatty acids by hydrolytic and fermentative aerobic bacteria, (2) Acetogenesis – conversion of sugars into short-chain acids, namely acetic acid, and (3) Methanogenesis – conversion of acids to methane by anaerobic bacteria [4]. Using the biogas technology can result in a smoke-free as well as ash-free kitchen. This eliminates the suffering of women and children from the pollution in the developing countries [2]. Biogas can replace the costly firewood and also provide a clean and easily controlled source of renewable energy produced from organic waste materials [5]. Biogas, being flammable, can produce approximately 600 BTU per cubic foot of heat which is relatively low when compared to pure methane (995 BTU per cubic foot). In addition to animal and plant waste, bio digesters can also be fed with municipal waste. This capability of biogas systems can substantially reduce the potential environmental pollution as municipal is a major source of pollution. The key reason for a biogas plant to be a successful project in a rural setting is because the major raw materials – animal and plant waste – are abundant. It saves the people from price and supply fluctuations of convention fuels and fertilizers .
Livestock is a demand driven commodity which has a good nexus as an unavoidable asset for the whole animal world. Sometimes it seems to become a liability when not managed properly. One of the best cited prospect for the above reason is liberation of waste from livestock and their proper utilization so as to prevent the dissemination of especially Green House gases more particularly CH4. There may many ways for the disposal and utilization of manure be adopted in both rural and urban areas. Composting is an aerobic degradation of organic compounds. Vermi –composting may be adopted as it includes inclusion of earthworm for the above same purpose. Panchgavya, a medicinal usable product is also explored as an alternate feasible item from the cow.
Management of Waste from Dairy Farms
