Explore the possibility of extracting essential nutrients like phosphorus, nitrogen, potassium and carbon from human excreta and replace fertilisers used in agriculture with them, the Niti Ayog has advised all states.
Faecal sludge is a rich source of nitrogen (N), phosphorous (P) and potassium (K), the three essential nutrients used in crop production across the world. But India relies heavily on imports to meet its demand for phosphorous and potassium, which are now limited and depleting further.
Intelligent use of faecal sludge, which is currently being disposed of indiscriminately, is an easy solution to meet the country’s demand for these nutrients.
In one day, a human being produces 30 grams (gm) of carbon, 10-12 gm of nitrogen, two gm of phosphorus, and three gm of potassium through human excreta, according to the International Water Management Institute.
“The solid matter that humans produce is largely organic,” Vijay Athreye, founder of non-profit FINISH Society, which is working on a similar project in Talcher in Odisha, said.
“It is carbon, phosphorous, plus a whole lot of other nutrients. We consume these nutrients in the form of food. For example, phosphorous remains in leaves. We consume those leaves. Thus, it stays in our body and then we excrete it,” he added.
Indiscriminate use of chemical fertilisers also reduces the soil’s health by killing microorganisms that nourish it. The average organic carbon content in soil, an index for soil health, is a low 0.3-0.4 per cent, according to Indian Council of Agricultural Research. This is well below the acceptable 1-1.5 per cent.
The advice from Niti Aayog Chief Executive Amitabh Kant to chief secretaries of all states in a letter came after he chaired a meeting on September 20, 2019. The event witnessed participation from different non-profits that have been working on the issue of nutrient recovery from faecal sludge.
Niti Aayog discussed a model in the Nilgiris, Tamil Nadu during the meeting, where faecal sludge was being distributed among farmers at a subsidised price after being turned into co-compost, to be used in agriculture in place of fertilisers.
The project is run by Rural Development Organisation Trust, a Tamil Nadu-based non-profit.
Results from the Nilgiris experiment showed that the co-compost improved soil quality and helped in boosting crop production. Farmers in the area reported an increase in yields and better quality produce.
All states were advised to consider such models and contact the non-profits working in the area to explore such a possibility in their jurisdictions, SK Singh, director, managing urbanisation, Niti Aayog, told Down To Earth.
“State governments have to now check its feasibility. Initiatives like these will take time to be adopted. It's a big country,” he said.
“It is a long-drawn process. Once we get some response, we will also have to look into the issue of vetting the technology and bringing some standardisations since currently there are none. We will need to assess how much of these organic fertilisers could be returned to the soil in a cost-effective way,” Singh added.
Its implementation can solve another big problem for India. When the country became open defecation free in October 2019, the next big concern was poor infrastructure for faecal sludge management.
Projects such as those in the Nilgiris and Talcher can help create a circular economy in sanitation —safe collection, treatment and reuse of faecal sludge.
“Linking sanitation and solid waste management with agriculture is the need of the hour. Without recycling, cities will continue to constitute vast sinks for waste including valuable crop nutrients and organic matter,” Kulwant Singh, chief executive of 3R WASTE Foundation, who attended the Niti Aayog meeting, said.
“A request to organise a faecal sludge management-related conference involving all states was also proposed by Niti Aayog. We are working on it currently,” he added.
Source ( Down To Earth)