From its birth in British India in 1847, modern irrigated desert agriculture has grown in just more than a century to produce one-third of the world's crops. Until the techniques of civil engineering were wedded to the ancient art of irrigation on the plains of the Punjab, most crops were rain-fed, except in areas such as the Nile Valley, where reliable seasonal floods made irrigation practical. Today, in contrast, we have made the desert bloom, giving ourselves fresh produce yearround and making the difference between survival and starvation in much of the developing world. Without irrigation, it would not have been possible to farm the high-yielding seeds of the Green Revolution, which greatly reduced the threat of famine in Asia and Latin America. But now, after a century of heavy irrigation, serious side effects are beginning to appear. Soils are becoming salinized by the cycles of wetting and drying in an arid climate, and wildlife has been poisoned by toxic drainage pumped from beneath irrigated fields where it has built up over time. These side effects have caused some to predict that the bounty of modern desert agriculture may not be sustainable, but others see hope of reducing the side effects through vastly improved water management.