National Geographic : 2011 Apr
THE BIG IDEA tillage because they leave the ground bare much of the year. That allows weeds to invade. Above all, leaving the ground bare after harvest and plowing it in planting season erodes the soil. No-till farming and other conservation practices have reduced the rate of soil loss in the U.S. by more than 40 percent since the 1980s, but it's still around 1.7 billion tons a year. Worldwide, one estimate put the rate of soil erosion from plowed fields at ten to a hundred times the rate of soil production. "Unless this disease is checked, the human race will wilt like any other crop," Jackson wrote 30 years ago. As growing populations force farmers in poor countries onto steeper, erodible slopes, the "disease" threatens to get worse. Perennial grains would help with all these problems. They would keep the ground covered, reducing erosion and the need for pesticides, and their deep roots would stabilize the soil and make the grains more suitable for marginal lands. "Perennials capture water and nutrients 10 or 12 feet down in the soil, 11 months of the year," Glover says. The deep roots and ground cover would also hold on to fertilizer---reducing the cost to the farmer as well as to the environment. The perennial wheat-wheatgrass hybrid now growing at the Land Institute can already be made into flour. Yields are too low to compete with annual wheat in Kansas---but maybe not in Nepal, which has steeper slopes and a harsher climate, and where a researcher is now testing perennial hybrids in small plots. Amber waves of perennial grain may be decades away, but the emergence of cheap DNA sequencing is allowing plant breeders to work much faster than they used to. Buckler thinks that for a tiny fraction of the billions spent annually on corn research, one could create field-testable perennial corn in as little as ten years. "I think we should take a shot at revolutionizing agriculture," he says. ---Robert Kunzig Perennials are thrifty. eir long roots hold on to soil, water, and fertilizer, which means less pollution.