China’s 1.4 billion people are building up an appetite that is changing the way the world grows and sells food. The Chinese diet is becoming more like that of the average American, forcing companies to scour the planet for everything from bacon to bananas.

But China’s efforts to buy or lease agricultural land in developing nations show that building farms and ranches abroad won’t be enough. Ballooning populations in Asia, Africa and South America will add another 2 billion people within a generation and they too will need more food.

That leaves China with a stark ultimatum: If it is to have enough affordable food for its population in the second half of this century, it will need to make sure the world grows food for 9 billion people.

Its answer is technology.

China’s agriculture industry, from the tiny rice plots tended by 70-year-old grandfathers to the giant companies that are beginning to challenge global players like Nestle SA and Danone SA, is undergoing a revolution that may be every bit as influential as the industrial transformation that rewrote global trade.

The change started four decades ago when the country began to recast its systems of production and private enterprise. Those reforms precipitated an economic boom, driven by factories, investment and exports, but the changes down on the farm were just as dramatic.