Phosphorous: Diminishing glow Business Daily from THE HINDU group of publications Monday, Aug 04, 2008 Anmol Sethy
Dwindling supplies of phosphorous, a critical input for agriculture, could lead to a crisis situation if timely action is not taken.
Amidst all the noise over the rising price of crude oil, not many seem to have noticed that the price of phosphorous (P), an element that lies at the core of modern agriculture, has risen by more than 700 per cent in the last 14 months to reach a whopping $367 per tonne.
While mounting oil prices burn deep holes in our pockets, we don’t directly deal with phosphorus. It is time to turn the focus on phosphorous and understand why its dwindling supplies are a threat to us.
Occurence
Phosphorous is present in all living beings as a micronutrient and in basic life compounds such as DNA and ATP. Along with nitrogen (N) and potassium (K), it forms the bedrock of agricultural growth.
Phosphorous deficiency in soil is one of the major reasons for limited crop production. It is also one of the critical deficiencies in livestock. (US Department of Agriculture (USDA) Information Bulletin No. 378, issued in 1975).
The unprecedented rise in food production that we have seen over the last century has been, to a good extent, due to fertilisers of these three elements being put to use. Most farms, in today’s world, do not have enough amount of phosphate (a combination of one phosphorous atom with four oxygen atoms) or do not receive the requisite amount naturally.
To meet this ever rising gap between the phosphates naturally available in the soil and what is actually required, mankind’s reliance on fertilisers is rising continuously. This makes the demand of phosphorus very inelastic.
With the population continuing to grow and overexploitation continuing to degrade soil quality, the demand for fertilisers will not stop growing. In a natural ecosystem, phosphorous keeps getting replenished in the soil through the decay of dead leaves and branches. Nowadays, though, as all of the agricultural product is used in one way or another, there is hardly any chance of phosphorus getting replenished in the soil.
Fertilisers act as the principal source of water-soluble phosphorous. Unfortunately, most of this gets washed away with rains and reaches the ocean and hence practically becomes irrecoverable.
Exploitable reserves
In fact, as much as 95 per cent of phosphate rock extracted today is being used for fertiliser production. The worldwide production of phosphate rock has been hovering around the 140-150-million-tonne mark for the past five-six years (http://minerals.usgs.gov/minerals/pubs/commodity/phosphate_rock). Of this, China and Morocco produce 22 per cent and 17 per cent, respectively. Both the countries together also account for 68 per cent of exploitable reserves (high phosphate conc. ~ 35 per cent) which is around 180,000 million tonnes.
If the current consumption pattern is maintained, the existing exploitable reserves are enough to last more than a century.
But assuming a growth of 2 per cent in consumption rate — which is reasonable considering the rising population as well as food consumptions in countries such as India and China and continuous degradation of soil — these reserves will not last beyond 50 years. The rate can be expected to rise further due to a thrust on corn-based biofuels. Corn production is phosphate fertiliser intensive and when corn plants are used for biofuel production, the whole plant is consumed, leaving no possibility for natural phosphorus recycling.
Statistical analysis by Patrick Deary shows that the world’s phosphate production may have already peaked (http://energybulletin.net/node/33164). And, as we see in the case of oil, this is the time when the supply becomes a constraining factor and prices spiral out of control.
As in the case of oil, one can expect that further rise in production will be expensive and tougher. This will be so because one will need to access reserves that are remote or of poorer quality.
The need to conserve
Considering that phosphorus is a necessity and has no substitute, the scenario can lead to several outcomes. Foremost is that agriculture takes a hit and we see a sustained inflation in food prices as we are seeing now.
Second, the disproportionate phosphate rock distribution across the globe may lead to a new OPEC kind of organisation. This situation, in some time, can ring alarm bells for countries such as the US, India and Europe, which import phosphate for fertilisers and are already under a huge oil import bill.
The situation also raises questions on the renewability of biofuels if the very ingredients that go into its manufacturing are not readily available.
To overcome this challenge, besides continuous research on inventing crops that require less phosphorous, we also need to start looking into natural ways of conserving Phosphorous.
Going into these methods is beyond the scope of this article, but some methods immediately come to mind. One is using Terra Petra form of farming, where charcoal is added to the soil to prevent minerals from getting washed away.
Second is to further promote the use of traditional methods of using human and animal wastes to produce manure. As fertiliser prices rise, farmers will tend to use them more judiciously, thus helping in softening the demand.
Demanding situation
In the end, questions can be raised about whether the peak has actually occurred or not, whether improving technology and chances of discovery of new reserves have been considered or not.
However, the point remains that we are posed with a significant challenge: On the one hand, phosphorous requirement is set to rise because of rising consumption and diminishing soil fertility.
On the other hand, reserves are limited and the phosphorous production seems to have reached supply constraint. The fact that phosphorous has no substitute makes the situation even more demanding. And whether evolving technology and proactive implementation of natural methods will enable us to overcome the challenge or not remains to be seen.
