Overuse of fertilizer has led to phosphorus shortages and water pollution. But farms might not need so much to grow healthy crops.
ON AN OVERCAST day, Roger Sylvester-Bradley walks along a hawthorn hedge, collecting a thick rind of mud on his leather boots, before stepping into a gently sloping field of barley.
He stoops to pluck an ankle-high seedling from the ground and examines its healthy mop of fine white roots. Turning them in his hands, he says, “when you see a plant that’s deficient in phosphorus, it doesn’t look like this.”
That’s something of a surprise to Sylvester-Bradley, a crop scientist at ADAS, an agricultural consulting company in Cambridge, England. Phosphorus occurs naturally in soil and is a critical nutrient for plant growth. For centuries, farmers have added extra to their fields to boost harvests, but Sylvester-Bradley and his colleagues are studying ways to produce food using less of it.
The reasons are twofold: First, phosphorus runoff from farms contributes to widespread water pollution. Second, we don’t have phosphorus to waste.
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