“Three out of four farmers in developing countries farm in the hills,” said Harold R. Watson, an American agricultural missionary. “When they hold a fistful of exhausted soil and let if fall to the ground, they feel their livelihood slipping through their fingers.”
Watson was then the director of the Davao-based Mindanao Baptist Rural Life Center, a non-government organization based in Kinuskusan, Bansalan, Davao del Sur. “Land degradation is a problem that is affecting the standard of living of many nations, but especially of the millions who live on and farm the hillsides,” he said after accepting the Ramon Magsaysay Award in 1985 for international understanding.
Watson considers topsoil one of the earth’s most valuable resources. And yet no one pays attention to it. This is especially true in the Philippines, one of the most populated countries in Asia with a population growth rate of 2.3 percent. “Soil loss is an Asia-wide problem,” he deplored.
In the Philippines, the hilly agricultural lands under cultivation have lost about two-thirds of their valuable topsoil, he said. In 1988, the Department of Environment and Natural Resources (DENR) released a report stating that 22 provinces in the country had “alarming” soil erosion rate.
Batangas in Luzon and Cebu in Visayas had been reported to have lost 80-85% of their topsoil to erosion. Marinduque had 75-80% soil erosion while Ilocos Sur and La Union had 60-70. Zamboanga del Sur, Zamboanga del Norte, Lanao del Norte, Lanao del Sur, Misamis Oriental, Bukidnon, North Cotabato, South Cotabato, Davao del Sur, Davao Oriental, Davao del Norte, Negros Oriental and Occidental, Iloilo, Aklan, Capiz, and Antique had more than 50%of their soil eroded.
“Soil erosion is a quiet crisis, an insidious, largely man-made disaster that is unfolding gradually,” Dr. Noel D. Vietmeyer wrote in the foreword of the book, Vetiver Grass: A thin green line against erosion. “In many places it is barely recognized; the soil moves away in such small increments from day to day that its loss is hardly noticed. Often the practices that cause the greatest losses in the long-term lead to bumper crops in the short term, thereby creating an illusion of progress.”
Nothing new
Soil erosion is not a new phenomenon. Archeological sites of civilizations, studies showed, were undermined by soil erosion. The fertile wheat-growing lands that made North Africa the granary of the Roman Empire are already desert. The lowlands of Guatemala that once nourished a thriving Mayan culture of five million people were drained of their fertility by soil erosion.
Twice in this century, the United States has faced the economic and environ-mental ravages of escalating soil losses, first in the Dust Bowl era of the thirties and a second time early in the eighties. Of the former, John Steinbeck describes the degradation of the land in painful detail in the opening pages of The Grapes of Wrath:
“The wind grew stronger… The dust lifted out of the fields and drove great plumes into the air like sluggish smoke… The corn fought the wind with its weakened leaves until the roots were freed by the prying wind and then each stalk settled wearily sideways toward the earth and pointed the direction of the wind.
“The dawn came, but no day. In the grey sky a red sun appeared, a dim red circle that gave a little light like dusk; and as that day advanced, the dust slipped back toward darkness, and the wind cried and whimpered over the fallen corn.”
Creeping enemy
In the humid tropics, starting from a sandy base, a soil can be formed in as little as 200 years. But the process normally takes far longer. Under most conditions, soil is formed at a rate of one centimeter every 100 to 400 years, and it takes 3,000 to 12,000 years to build enough soil to form productive land. “This means that soil is, in effect, a non-renewable resource,” says a publication published by the UN Food and Agriculture Organization (FAO). “Once destroyed, it is gone forever.”
Although soil erosion does occur naturally, the process is slow. However, man’s intervention has increased the rate of natural erosion. According to David Pimentel, an American agricultural ecologist at Cornell University, exposed soil is eroded at several thousand times the natural rate. Under normal conditions, each hectare of land loses somewhere between 0.004 and 0.05 tons of soil to erosion each year – far less than what is replaced by natural soil building processes.
On lands that have been logged or converted to crops and grazing, however, erosion typically takes away 17 tons in a year in the United States or Europe, and 30 to 40 tons in Asia, Africa, or South America. On severely degraded land, the hemorrhage can rise to 100 tons in a year!
The world reportedly loses the equivalent of 5-7 million hectares of farmland through erosion each year. This is equivalent to the land area of Belgium and the Netherlands combined. To correct the problem would cost US$25 billion. “The alternative,” if the problem is not corrected, “is famine,” warned the UN food agency.
Consequences
Dr. Nyle C. Brady, in his book called The Nature and Properties of Soils, wrote: “No other soil phenomenon is more destructive worldwide than is soil erosion. It involves losing water and plant nutrients at rates far higher than those occurring through leaching. More tragically, however, it can result in the loss of the entire soil.”
Erosion starts off a chain reaction of events, of which the first sign is a decline in crop yield. Then, as soil is lost and gullies deepen, the use of which land is put must be changed: crop land becomes pasture, pasture turns to scrub.
Eventually, the land goes out of production altogether. Food becomes expensive and scanty, and malnutrition more prevalent. In many developing countries like the Philippines, a loss of agricultural revenue means more than food shortage.
Because the agricultural sector is so important to the economy, national plans for development may be delayed and industrialization held back. The balance of payments situation may worsen if the country depends on cash crops.
The rural population finds life increasingly hard and seeks a better life in the cities. The latter, often incapable of providing adequate services for the populations they already have, can offer little to the new arrivals except a place to build a primitive shelter in a shanty town. Social unrest and political discomfort soon follow.
Meanwhile, the urban areas start to suffer directly from the downstream effects of erosion. The soil that was once the natural resource of the farmers becomes the mud and silt of the valleys below.
Huge quantities of it fill up the rivers, drastically reducing the amount of water they can carry. As rivers silt up, navigation begins to suffer; what were once highways for traffic and a productive source of high-quality protein can become no more than meandering mud banks.
When heavy rain comes, these rivers overflow and flood farmland and cities indiscriminately. Damage can be colossal. Remember the Ormoc tragedy, which killed thousands of people?
Costly irrigation, flood control and hydroelectric schemes may also be wrecked as reservoirs designed to last many decades fill with silt in little more than a decade.
The economic result of downstream erosion is a rise in the cost of energy, water, food and goods formerly transported by river. The chances of further development schemes downstream are also eliminated.
Lester Brown, then the president of the Washington-based Worldwatch Institute, points out that the immediate effects of soil erosion are economic but in the long run its ultimate effects are social. “When soils are depleted and crops are poorly nourished, people are often under-nourished as well. Failure to respond to the erosion threat will lead not only to the degradation of land, but to the degradation of life itself,” he said. (To be continued)
