By: Elizabeth Ryan

Growing food uses more water than any other human activity. Millions of people could be fed and more than a billion could have enough water for their day to day needs with small changes in land and water usage.

University of Minnesota research published last month investigated the connection between water sustainability and food security.

Kate Brauman, a postdoctoral fellow with the University’s Institute on the Environment and lead author of the study, said the focus of the research was on how much food could be produced from each drop of water.

“If we’re using water in agriculture,” she said, “are we getting enough food bang for our water buck? If we’re making tradeoffs, are we making good tradeoffs?”

The research took a theoretical approach to isolate the lowest performing crops and see what raising their level of performance slightly would do. These low performers are crops that use a lot of water for little caloric gain — like growing rice in a dry climate.

Brauman said the total impact of improving just the bottom level crops could use less water and produce more crops.

For rain fed croplands, the research showed 110 million people could be fed without using additional water every year by adjusting the low performers.

Improving the bottom level crops for irrigated croplands could meet the annual household water demands of about 1.4 billion people.

“Obviously, you couldn’t necessarily get all of these gains,” Brauman said. But these small ‘crop per drop’ changes could still make a big difference, she said.

Making models a reality

The next step in making these gains a reality lies in work that researchers are doing on the ground.

Brauman’s study looked at 16 different crops, including wheat, legumes and some of the other biggest staple foods around the world.

Stefan Siebert, a study co-author from the University of Bonn in Germany, calculated how much water different crops need to be using. Brauman combined this data with information on crop yields from the University’s Global Landscapes Initiative to create the ‘crop per drop’ models.

The next step is to find out how to actually increase the yields, said IonE program director Paul West.

“We help … identify which crops in which places are having the biggest effect on water, on climate, on habitats,” he said.