From National Geographic:

As the world population climbs and water stress spreads around the globe, finding ways of getting more crop per drop to meet our food needs is among the most urgent of challenges.

One answer to this call is drip irrigation, which delivers water directly to the roots of plants in just the right amounts. It can double or triple water productivity – boosting crop per drop – and it appears to be taking off worldwide.

Over the last twenty years, the area under drip and other “micro” irrigation methods has risen at least 6.4-fold, from 1.6 million hectares to more than 10.3 million.

The most dramatic gains have occurred in China and India, the world’s top two irrigators, where the area under micro-irrigation expanded 88-fold and 111-fold, respectively, over the last two decades. India now leads the world, with nearly 2 million hectares (about 5 million acres) under micro-irrigation methods.

For more, see: Drip Irrigation Expanding Worldwide