Manure is like a double-edged sword. It can have positive as well as negative effects which depends on how it is used. Manure leads to increase in CH4 and nitrogen emission which are greenhouse gases and air pollutants, water pollution if the liquid manure is excreted to water stream or ground water pollution. Additionally, they cause nuisances, through foul odour in surrounding areas and breeding ground for mosquitos and flies which then spread diseases.
On the other hand if used wiselythrough integrated soil management, vermin-compost, it can enhance the organic matter of the soil, reducing the need for inorganic fertilizers with immense positive impact on the environment. Although it is important to emphasize that using fresh manure without proper decomposting also has severe implications for spread of infestation.
Also, there is immense scope for conversion to biogas which can serve as a non-polluting source of renewable energy. The potential of biogas can be judged from the fact that India produces 980 million tonnes of wet dung from bovines, which could produce 41,000 million cubic meters of bio gas per annum, sufficient to produce196 MW of electric power. The impact of organic fertilizers on soil health are well proven and needs no explanations. These efforts can significantly minimize the environment foot prints of livestock.
With the recent spate of climatic disasters, it is not only important, but critical to minimize the negative impact on environment. The question is: What can we actually do? Where do we start?
Situation of manure in crop-livestock system
More than 80 percent of nutrient and organic matter is excreted as dung and urine. This should be used to supplement soil nutrients. However the current practices rely on extensive use of chemical fertilizers, limiting the use of manure.
The existing dung management practice in the country (like drying dung as dung cakes and using it as fuel) is neither an efficient method, nor it is environment friendly. The urine from cows and buffaloes mostly flows freely and gets wasted.
At the global level, several initiatives have been undertaken to harness the positive potential of manure through proper management. Institutes like the International Livestock Research Institute (ILRI), Global Agenda on Sustainable Livestock (GASL) and other international research institutions are conducting research to understand the gap between existing and best practices and undertaking projects to enhance farmer awareness regarding good practices. International institutions like the Netherlands Development Organisation (SNV) and UNFAO are working with local institutions in developing policies related to manure management and change of traditional manure management practices in Asian, African and Sub Saharan countries.
It is time to initiate action on this front at the country level. Some starting point are noted below:
– Initiate dialogue with key stakeholders including research institutes, policy makers, farmers, NGOs, donor agencies to understand the key issues and constraints
– Initiate research to understand the current practices on manure management, the reasons why farmers follow these practices and what it would take to encourage the farmers to follow improved practices.
– Focus on policy aspects required for improving manure management
– Enhance farmer awareness regarding importance and practices for efficient manure management.
These will be the baby steps required to actually change manure from waste to a valueable resource contributing positively to agriculture and environment.
Dr. Meeta Punjabi Mehta, Ph.D, Agriculture Economist, Creative Agri Solutions & Dr. Ankaj Sharma, Research Associate, Creative Agri Solutions
1Teenstra, E. et al (2104) Global Assessment of Manure Management Policies and Practices