Every good farmer or gardener knows that sometimes you need more than sunlight and water to make things grow. You need to give plants food in the form of fertilizer. It could be organic compost or manure, but most of the world these days relies on chemical fertilizer – almost 200 million tons of it last year.
Most of the chemical compounds in fertilizer are abundant and easy to produce. But one element, phosphorus, is much less common. In fact, a few years ago, some scientists sounded the alarm that phosphorus supplies were getting tight. Forget peak oil, they said, what we really need to worry about is peak phosphorus because without it, we can't produce food.
It is a vital element for producing food and now its price is rising causing concern about both supply and pollution.
Reporter Jori Lewis traveled to Morocco to look at the problems and opportunities surrounding this key ingredient in the global food supply.