FLAGSTAFF, Ariz., Nov. 1 (UPI) -- Crop production could decline as climate change affects soil nutrients, possibly affecting the lives of one-fifth of the world's population, experts say.
As dry regions of the world become even drier, water will not be the only resource in short supply -- levels of nutrients in soils will also probably be affected, they said.
Scientists reporting the results of their study in the journal Nature said most of the 17 nutrients that plants need to grow to their potential -- such as nitrogen and phosphorus -- are soil resources that could be affected by climate change.
As the climate becomes more arid, they said, nitrogen will decrease and phosphorus will increase.
"Both are essential for plant growth, and both are typical components of fertilizer, but both need to be around in the right quantities for plant growth to proceed most efficiently," study co-author Matthew Bowker, a professor of forest soils and ecosystem ecology at Northern Arizona University, said.
"It's like a situation where you're making hamburgers but run out of beef," he said. "You can't just slip in another bun and still produce a hamburger."
Drylands, defined by predominantly lower levels of moisture, cover about 41 percent of the planet's surface, and people who depend on those ecosystems for crops, livestock forage, fuel and fiber will find their resources increasingly restrained, the researchers suggested.