National Geographic : 1938 May
TREELESS WASTES IN CHINA'S LOESS COUNTRY SERVE AS A LABORATORY FOR AMERICA'S STUDY OF SOIL EROSION Problems raised by vanished forests and intensive cultivation through the centuries in Kansu Province have interested U.S.Department ofAgriculture scientists eager to check land wastage in the United States. Farms flourish in the valley because of intelligent conservation by terracing. Much ofNorth China once was timbered, but succeeding generations cut down the trees to obtain wood and more cleared land. This left the soil prey to destructive forces.