India is running out of water for crops. Most of the water-intensive agriculture in the nation takes place in Punjab, a state in the northwest that makes up 2 percent of the country’s territory but provides more than 50 percent of its grain reserves. Farmers there currently pump out 45 percent more groundwater than is replenished by monsoon rains.

The problem has arisen in part because Punjabi farmers have veered away from growing traditional crops that are suited for semiarid land, such as wheat and corn, and turned instead to more profitable, but water-intensive, rice. “If Punjab is to continue as the food grain capital of India, modern agricultural practices will have to take into account the water situation and create a feasible long-range plan for a sustainable future,” says Shama Perveen, an associate research scientist at Columbia University’s Water Center, who has been working in the region. She and several colleagues from Columbia, in collaboration with Indian agriculture scientists, are testing a piece of that plan: two conservation tools that could help farmers use less water, even if it won’t alter their choice of crops.