• Hindol Sengupta

Phosphorous, seaweed and the future of food in India

The world is running out of phosphorous. This is bad news for major agrarian countries like India which are likely to provide a large amount of future food supplies of the world. But there could be some interesting solutions.

An open phosphate mine.

The mineral phosphorous is a critical ingredient in agriculture. But its supply and demand are heavily skewed, a disproportionate majority, anywhere between 70-80 per cent, comes from a single source in Morocco.

And if that is not enough, the western Saharan part of Morocco is conflict-ridden and heavily contested. Most other countries that are major suppliers like China, Algeria, Syria, and the United States are conflict-ridden, and Estimates suggest that starting 2030, the global supplies of phosphorous will start to dwindle and in about a hundred years (some say as early as 2050), the world will run out of phosphorous casting a worrying shadow on agricultural productivity in the future.

While ‘peak phosphorous’ maybe some years in the future, there has already been one indication of the crisis to come – the price of phosphorous fertilizer grew 800 per cent in 2007-8. Since then, in 2010, the International Fertiliser Development Centre (IDFC) adopted new methods of calculating global phosphorous reserves and concluded that the world had 65 billion tonnes of phosphorous, and not the earlier assessment of 16 billion tonnes. Though not all researchers agree with this assessment.

Around the world, countries have put phosphorous supplies on critical lists. In 2013, the European Sustainable Phosphorous Platform was created, and the following year, the European Union announced phosphorous as a critical raw material, one of 20. From Germany to the United States, new programmes to conserve phosphorous supplies came up in the future like the North American Partnership for Phosphorous Sustainability and Australia’s Global Phosphorous Research Initiative. Several significant producers of phosphorous like China and the U.S. have progressively clamped down on the exports of phosphorous.

A phosphorous crisis is naturally cause for worry for a country as heavily reliant on agriculture, and which supplies, and is will supply, a large part of global food supplies in the future, as India. The country also faces the challenge of diminishing soil fertility making it even more dependents on the use of external macronutrients like phosphorous. India is one of biggest importers of phosphorous in the world.

Does India have phosphorous deposits of its own? It does. Not a very significant amount by the standards of other phosphorous-rich countries, but enough to merit mining. But as environmental awareness has grown, so have apprehensions about the Jhamarkotra mines in the Aravalli hills about an hour-and-half drive from the city of Udaipur in the western Indian state of Rajasthan. The concern is that pollution from the phosphate mines might affect the water quality of the picturesque city of lakes.

So, what is the alternative to mined phosphorous use in agriculture? One way is to recover phosphorous by treating faecal sludge – analysis has shown that India produces about 200 million tonnes of phosphorous which could be retrieved by treating faecal sludge. This is one way to stop the wastage of precious phosphorous (humans can digest only 10 per cent of the phosphorous they intake). When phosphorous fertilizer is applied to the soil in agriculture, about half of it is wasted in runoffs.

Treating those runoffs more intelligently would also help extract back useful mineral. The question is how? There is a simple answer. What happens to those runoffs? They usually drain into a waterbody. Now water heavy with phosphorous leads to eutrophication or the birth and spread of weeds and other aquatic plants on surface water.

Research shows that, “… seaweed fertilizers are better than other fertilizers; they are very economic and cheap. Seaweed fertilizers are preferred not only due to their nitrogen, phosphorus and potash content but also because of the presence of trace elements and metabolites similar to plant growth regulators. Seaweed extracts are utilized to enhance seed germination and plant growth; seaweed extracts have been used to increase crop yield, improve growth and induce resistance to frost fungal and insect attack and increase nutrient uptake from soil”.

China, Japan, and Korea are world leaders in seaweed cultivation and India has a good opportunity in this field because of its more than 17,000 kilometre-long coastline with 821 varieties of seaweed. Earlier this year, the Indian government has announced plans to expand seaweed cultivation from around 2,500 tonnes a year to 11.5 lakh* tonnes.

The future of food in India, then, might in intrinsically connected to seaweed, and, some repurposed faecal sludge too.

*10 lakh = one million


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