Vegetable growers in the Philippines are finding that no-till farming not only saves their topsoil but may even lessen the danger of landslides!
Four years of experiments in the Cordillera—the “salad bowl” of the Philippine highlands—show a 50–70 percent reduction in soil erosion because the farmers neither plow nor hand-weed. The region specializes in vegetables because its 6,000-foot elevation keeps the soil cooler and less humid than at sea level hear Manila. However, the steep slopes also mean high risks for both soil erosion and landslides.
Gil Magsino, of the University of the Philippines at Los Banos, says that even hand-weeding breaks up and loosens the soil structure. Then heavy tropic rains come to wash away the soil, its nutrients, and any fertilizer the farmers have been able to afford.
During 2009, in fact, Typhoon Pepeng caused landslides that killed some 200 people in the Cordillera region and U.S. military helicopters were sent in to help rush rescued landslide victims from the cut-off city of Baguio to regional hospitals.
A similar mudslide phenomenon hit southern Minnesota and Wisconsin in 2007, after a 12-inch rain. Four people were killed, small towns had to be evacuated, and soil sloughed off any unprotected hillsides. As it happens, that sand-hill region holds the second-largest concentration of organic farms in the U.S.—and organic farmers don’t allow no-till because it needs herbicides.
Sediment expert Stanley Trimble of UCLA had long studied the region’s Coon Creek watershed, and returned after the 2007 storm to view the impacts. “It was amazing,” Trimble reported. “I saw a narrow valley with no-till corn on one shoulder, no-till soybeans on the other shoulder, and in the valley was a sediment basin that had collected no sediment at all. The no-till had done a fabulous job.”
While U.S. no-tillers rely heavily on Roundup, Gil Magsino has been recommending that Filipino farmers spray between their crop rows with a mild solution of the herbicide paraquat. He says using strong herbicide solutions would kill the weeds and also their roots. The mild herbicide solution suppresses the weeds long enough to give the crops a head start—while keeping the weed roots intact below-ground. That helps hold the soil and its nutrients so the crops can benefit from them.
The farmers also gain from no-till’s low input costs. The herbicide costs far less than the diesel fuel otherwise needed to plow the fields. American farmers invented no-till during the first OPEC oil embargo of the 1970s for exactly the same initial reason—to cut fuel costs. Green manure crops, planted to cover the soil surface when no crops are growing, cut down on the need for commercial fertilizer. Then the herbicides kill the cover crops when the grain or vegetables are planted; otherwise the cover crops become weeds themselves.
No-till is currently being used on more than 100 million acres of crops world-wide. Among the biggest users are the U.S., Canada, Argentina, Brazil, and Indonesia. In Canada, no-till has replaced the old clean-fallow system on the semi-arid prairies. The fallow system left the soils open to wind and water erosion most of the time. With no-till, yields are higher and soil losses have been radically reduced.
Soil erosion is man’s most ancient and implacable enemy; no-till practically eliminates it. No-till often doubles soil moisture in the fields; water sinks in rather than running off, and the crop residue on the surface keeps soil temperatures cooler. And no-till achieves all this while keeping crop yields high. It is the most sustainable farming system that will sustain both the people and the wildlife in the 21st century.
