With President Trump's visit to Beijing this week, there's been a lot of nervous talk about China's growing wealth and trade. The country will soon overtake the US to become the world's largest economy, and its government is aggressively pushing innovation in everything from solar power to artificial intelligence to electric cars. But one of China's most important industries is also one of its oldest: rice. It's unclear how much rice the POTUS enjoyed during his visit, but some seems likely--not only given his reported love of the stuff, but also its role in Chinese culture. People began cultivating the grain in China nearly 10,000 years ago. Today, rice is its biggest crop, with farmers growing roughly 200 million tons--more than any other country, and nearly a third of the world's supply--every year.