How Long Can We Last?

I stood on the Great Wall of China high on a hill near the borders of Mongolia. Below me in the valley, standing up square and high, was a wall that had once surrounded a city. Of the city, only a few mud houses remained, scarcely enough to lead one's mind back to the time when people and household industry teemed within the protecting wall.

The slope below the Great Wall was cut with gullies, some of which were fifty feet deep. As far as the eye could see were gullies, gullies, gullies—a gashed and gutted countryside. The little stream that once ran past the city was now a wide waste of coarse sand and gravel which the hillside gullies were bringing down faster than the little stream had been able to carry them away. Hence, the whole valley, once good farm land, had become a desert of sand and gravel, alternately wet and dry, always fruitless. It was even more worthless than the hills. Its sole harvest now is dust, picked up by the bitter winds of winter that rip across its dry surface in this land of rainy summers and dry winters.

Beside me was a tree, one lone tree. That tree was locally famous because it was the only tree anywhere in that vicinity; yet its presence proved that once there had been a forest over most of that land—now treeless and waste.

The farmers of a past generation had cleared the forest. They had plowed the sloping land and dotted it with hamlets. Many workers had been busy with flocks and teams, going to and fro among the shocks of grain. Each village was marked by columns of smoke rising from the fires that cooked the simple fare of these sons of Genghis Khan. Year by year the rain has washed away the loosened soil. Now the plow comes not—only the shepherd is here, with his sheep and goats, nibblers of last vestiges. These four-footed vultures pick the bones of dead cultures in all continents. Will they do it to ours? The hamlets in my valley below the Great Wall are shriveled or gone. Only gullies remain —a wide and sickening expanse of gullies, more sickening to look upon than the ruins of fire. You can rebuild after a fire.

Forest—field—plow—desert—that is the cycle of the hills under most plow agricultures—a cycle not limited to China. China has a deadly expanse of it, but so have Syria, Greece, Italy, Guatemala, and the United States. Indeed we Americans, though new upon our land, are destroying soil by field wash faster than any people that ever lived—ancient or modern, savage, civilized, or barbarian. We have the machines to help us to destroy as well as to create. The merciless and unthinking way in which we tear up the earth suggests that our chief objective may be to make an end of it.

We also have other factors of destruction, new to the white race and very potent. We have tilled crops—corn, cotton, and tobacco. Europe did not have these crops. The European grains, wheat, barley, rye, and oats, cover all of the ground and hold the soil with their roots. When a man plows corn, cotton, or tobacco, he is loosening the earth and destroying such hold as the plant roots may have won in it. Plowing corn is the most efficient known way for destroying the farm that is not made of level land. Corn, the killer of continents, is one of the worst enemies of the human future.

We in America have another factor of destruction that is almost new to the white race—the thunderstorm. South Europe has a rainless summer. North Europe has a light rainfall that comes in gentle showers. The United States has the rippling torrent that follows the downpour of the thunderstorm. When the American heavens open and pour two inches of rain in an hour into a hilly cornfield, there may result many times as much erosion as results from two hundred inches of gentle British or German rain falling on the wheat and grass.

I asked county agents in a number of counties in the hill country of North Carolina the following question: "What is your estimate of number of cultivated crops secured on steep land after clearing and before abandonment of cultivation?" The answers from ten counties were as follows: 5; 20; 12; 10; 5 to 10; 10 or 12; 10 or more; 12; 5, extremely variable and 10. (See Figs. 2, 3, 4, 6, 9.) Ten tilled crops, and ruin has arrived! How long can we last?

Even Oklahoma, newest of the new, so recently wrested from the Indian, who did not destroy it, has its million miles of gullies and a kingdom of good land ruined and abandoned.

Five years ago there was not a gully on the place ... now it is badly cut by gullies ... all the top soil washed away, leaving nothing but the clay.... If not terraced ... the gullies [will] cut deeper until the rocks are touched or until all the clay soil is gone.... Five years ago...