National Geographic : 2015 May
By the Numbers EXPLORE TONS OF U.S. ALFALFA IMPORTED BY CHINA 648,980 CHINA’S RISING DAIRY DEMAND RAW MILK PROTEIN CONTENT IN CHINA U.S. ALFALFA HAY IMPORTED BY CHINA 2.8% 3.0% National standard Cows fed high-quality alfalfa DRINKING AND USE AT FARM 1% TO PRODUCE 1 GALLON OF MILK 1,182 GALLONS OF WATER IT TAKES GRAINS 51% GRASS AND HAY 16% OIL MEALS 14% OTHER FEED 18% 1991 2011 Percentage contributed by milk consumption 750,000 250,000 500,000 0 CHINA U.S. WORLD AVERAGE 1.6% 6.8% 7.3% 1990 1998 2,968 125 tons 21,321 206,923 2006 2008 2013 2011 2011 Net exporters Net importers Even though many farmers struggle to meet their crops’ demand for water in places such as drought-stricken California, every year they send billions of virtual gallons to other countries—in the form of the food and feed grown with that water. According to Arjen Hoekstra of the Netherlands’ University of Twente, the issue of agriculture’s water footprint—all the water used to produce a commodity and get it to a consumer—is contentious, since many farmers use scarce water to produce low-value export crops. Water is a public good, he says, so allocation systems ought to support its sustainable use. —Kelsey Nowakowski Thirsty Exports Chinese consumers drink more milk today than ever before. Because their appetite for dairy products is growing faster than Chinese farmers’ capacity to feed dairy cattle, those farmers now rely on alfalfa hay imports from the U.S. After dropping off Chinese goods in California ports, many containers are filled with alfalfa for the return trip. It’s often more cost-effective to send alfalfa from Los Angeles to Beijing than from California’s Imperial Valley to its Central Valley, where many dairy farms are located. Alfalfa improves the amount and quality of milk produced by dairy cows. WATER FOOTPRINT OF WHOLE MILK IN THE PEOPLE’S REPUBLIC OF CHINA ALFALFA IS CALIFORNIA’S LARGEST AGRICULTURAL WATER USER, CONSUMING MORE THAN FIVE MILLION ACRE-FEET** A YEAR. *Virtual water flow is all water used to produce a commodity, transferred virtually through trade to the consuming country. **One acre-foot is the amount of water that would cover one acre to a depth of one foot, or 325,851 gallons.