There are so much issues going on these days: war on drugs, extra-judicial killings, dengue vaccine, Acquired Immune Deficiency Syndrome, violence against women, climate change, genetically-modified organisms, deforestation, poverty, and politics.
But there is a kind of war that no one pays attention. To think, it deserves all the attention we have. After all, our existence depends on it. Without it, we cease to exist in this green planet.
Everyone know the enemy but no one seems to care at all. It is happening right before our eyes but no one is distracted. In fact, there’s no group making a call and doing a demonstration to stop it!
The enemy: soil erosion. It happens during day time when everyone is awake and notice that the soils are slowly eroding. It takes place at night time; while everyone is sleeping, the wind blows those soils away from where they are needed most.
Soil is needed to produce our food: vegetables, crops, fruits, and even livestock. Yet, we take it for granted. Gold, oil, minerals and precious stones command high prices which have led us to treat soil as mere dirt.
Just remember: “Without soil, there would be no food apart from what the rivers and the seas can provide,” reminded Edouard Saouma, former director-general of the UN Food and Agriculture Organization (FAO). “The soil is the world’s most precious natural resource.”
According to soil scientists, 58% of our total land area of 30 million hectares are susceptible to erosion. “For one, the magnitude of soil erosion in cultivated sloping areas has reached an alarming proportion,” deplored Angel C. Alcala, former secretary of the Department of Environment and Natural Resources (DENR) and also a Ramon Magsaysay Awardee.
Soil, aptly described as “the bridge between the inanimate and the living,” consists of weathered and decomposed bedrock, water, air, organic material formed from plant and animal decay, and thousands of different life forms, mainly microorganisms and insects. All play their part in maintaining the complex ecology of a healthy soil.
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 FAO publication. “Once destroyed, it is gone forever.” Which means that once the soil is carried away to the oceans – where they are not needed – there is no way it can be returned to its former state.
In nature, soil erosion occurs but the process is rather slow. It becomes faster only due to man’s interference. According to David Pimentel, an agricultural ecologist at Cornell University, exposed soil is eroded at several thousand times the natural rate.
“Under normal conditions, each hectare of land losses 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,” one study reported.
Several studies have shown that 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 30-40 tons in Asia, Africa, or South America. On severely degraded land, the hemorrhage can rise to 100 tons in a year.
“No other soil phenomenon is more destructive worldwide than is soil erosion,” wrote Nyle C. Brady in his book, “The Nature and Properties of Soils.” “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.”
What happens then? In their book, “Soil Erosion: Quiet Crisis in the World Economy,” authors Brown and Edward C. Wolf said soil erosion, for one, threatens food production. “The loss of topsoil affects the ability to grow food in two ways. It reduces the inherent productivity of land, both through the loss of nutrients and degradation of the physical structure. It also increases the costs of food production,” they wrote.
“When farmers lose topsoil, they may increase land productivity by substituting energy in the form of fertilizer,” the two authors continued. “Farmers losing topsoil may experience either a loss in land productivity or a rise in costs (of inputs). But if productivity drops too low or costs rise too high, farmers are forced to abandon their land.”
In the last 40 years, approximately 30% of the world’s arable crop lands have been abandoned because of severe soil erosion, according to a study by the Royal Commission on Environmental Pollution.
But there’s a good news. The Mindanao Baptist Rural Life Center (MBRLC) in Kinuskusan, Bansalan, Davao del Sur has an answer to soil erosion. It is through a farming technique called Sloping Agricultural Land Technology (SALT).
“The principle of SALT is the same as that used by the Ifugao tribes,” explains MBRLC Director Roy C. Alimoane. “All we are doing is suggesting using nitrogen-fixing trees and shrubs instead of rocks.”
In the SALT farm, you find a mix of permanent crops (cacao, coffee, banana and other fruit trees), cereals (upland rice, corn, or sorghum), and vegetables (bush sitao, winged beans, sweet pepper, tomato, eggplant, etc.).
And yes, SALT helps control soil erosion. Its study showed that a farm tilled in the traditional manner erodes at the rate of 1,163.4 metric tons per hectare per year. In a SALT farm, there is still erosion but minimal – 20.2 metric tons per hectare per year.
The rate of soil loss in a SALT farm is 3.4 metric tons per hectare per year, which is within the tolerable range. Most soil scientists place acceptable soil loss limits for tropical countries like the Philippines within the range of 10 to 12 metric tons per hectare per year.
In comparison, the non-SALT farm has a soil loss rate of 194.3 metric tons per hectare per year.
“When soils are depleted and crops are poorly nourished, people are often undernourished as well,” Brown and Wolf wrote in their book. “Failure to respond to the erosion threat will lead not only to the degradation of land, but to the degradation of life itself.”
And the war continues…