UNITED NATIONS -- In India's state of Punjab, where the country's "Green Revolution" began 40 years ago, another revolution may be in store. For four decades, India has encouraged food production through subsidies and other price supports to farmers there. Electricity is cheap, and water is free to whoever pumps it out of the ground. As a result, Punjab grows a fifth of India's wheat and 12 percent of its rice, while covering 1.5 percent of the country's land, according to the Columbia Water Center at Columbia University. But the "free" water may be exhausting water supplies, some warn. Unless something is done -- including, possibly, putting a price on water -- the future of "India's breadbasket" could hang in the balance.