National Geographic magazine, volume 87, no. 6 (June 1945)

Page 33

China Fights Erosion with U. S. Aid 647 it left its confining gorge and opened out into its broad flat outwash fan known as the Chengtu Plain. Twenty-two centuries ago Li Ping had no reinforced concrete, but he used local materials and hand labor. His plan was simple. Wood, bamboo, and stones picked out of the stream bed were his materials. With these he built uncemented but well-designed structures to divert water as he chose. He cut a canal through the toe of a slope of hard conglomer­ate rock, which fixed the size of the intake for the inner canal. The main river was to serve as the outer canal and carry off flood waters. "Fish's Snout" Divides the River The "fish's snout," a strong point estab­lished in midstream by piling up year after year boulders and gravel excavated from the channels on each side, divides the current into two feeder canals, which lower down are divided into nine canals to distribute flood water to prevent floods (page 660). These nine are further divided into 526 lat­erals and 2,200 sublaterals, providing irriga­tion water to an average depth of seven and a half feet for the entire Tu Kiang Project of 500,000 acres. The whole Chengtu Plain sup­ports 2,000 persons to the square mile, one of the densest populations in the world. Boulders and gravel rolled along the stream bottom by swift currents would shortly inter­fere with equal parting of the waters into the two canals. To safeguard against such fail­ures, Li Ping prescribed simple regulations which are set forth in six characters plainly carved into a prominent wall of the Er Wang Temple. The translation is "Dig the channel deep and keep the spillway low" (page 663). It was made a religious rite to carry out these measures each year before the ceremony of opening of the waters could be held. We were fortunate to be present at the opening. The Governor of the Province led the official ceremony by paying homage to the images of Li Ping, who began the project, and Er Wang, his son, who completed the job (page 645). Actually, the temple to Er Wang is more pretentious, and homage to him is greater because of the son's filial piety in completing the work which his father began. Priests sac­rificed two sheep and two pigs before the altars, and officials bowed before the images amid the noise of temple gongs. After the ceremonies, to the deafening sounds of bursting firecrackers the temporary cofferdam, which had been built to divert the river flow, was breached (page 644). Twenty men pulling on a bamboo cable turned over the temporary wooden tripods, and life-giving waters rushed through, to the acclaim of some 40,000 people. Then the river flowed down the inner and outer canals ready for another of the 2,200-year-old series of consecutive irri­gations. In forty centuries Chinese farmers have won the battle for food production in some places and lost it in others.* Sometimes ero­sion and floods have won and the people have failed despite centuries of effort. Neverthe­less, I have yet to find a major problem of land use for which some ingenious farmer of the past has not worked out a solution in whole or in part, either by chance or by de­sign. Generally, neither he nor his neighbors have fully appreciated his finding. This trial-and-error method has been costly, yet its findings are valuable. The Chinese farmers do not, as did our Puritan ancestors, "wrest a living from the soil," but work in conscious partnership with Nature. Love of the "good earth" is one of the most powerful social forces in China. Chinese farmers are the world's greatest experts in the use of fertilizers. For this reason they have been able to cultivate year after year for thousands of years the flat fields in the vicinities of towns and cities without serious depletion of the soil. Sewage Becomes Fertilizer in China Our method of sewage disposal would be national suicide for the Chinese. We break the animal-plant nutrient cycle by discharg­ing human waste into rivers and harbors and pollute these waters. We tax ourselves heavily thus to waste precious plant food; whereas the Chinese bid high prices for concessions to carry it back to their farm fields. Most Chi­nese farmers have pottery jars within an en­closure beside the road, offering invitations or inducements to the traveler to stop and con­tribute to this vital necessity for the next crop. We passed three months in Chengtu in training for our survey of the use of land in northwest China and in acquainting our field staff with principles of soil and water conser­vation and with facts and measures that had been worked out in our national program in the United States. Special emphasis was given to adaptation of findings in America to conditions in China. Our first objective throughout the course of our survey was to learn what the Chinese farmer had done, to observe farmer practice, and to find the places in his practice where our American experience would fit in to make best use of soil and water. * See "Farmers Since the Days of Noah," NATIONAL GEOGRAPHIC MAGAZINE, April, 1927.