Наука & Природа
мар 2, 2018
THE ULTIMATE WEAPON
The large pastures can be an answer to end the areas of deserts and ameliorate the effects of global warming, defends environmentalist and Zimbabwean farmer, Allan Savory who once was responsible for the slaughter of 40 thousand elephants.
By ALFREDO MIRANDA
It is understood among environmentalists: when large groups of herbivorous animals grazing in a certain place, the soil gets very degraded. The animals destroy vegetation as they eat part of plants and step the rest. Without vegetation and roots that help absorb water, the ecosystem can be compromised to the point of transforming the region into desert.
The biologist born in Zimbabwe, Allan Savory, thought so. In 1950, he took a polemical attitude to resolve this matter: he commanded the killing of 40000 elephants that, in theory, where responsible for the destruction of the vegetation of an African Park in Zimbabwe.
The measure suggested by the expert was carried out and the elephants were shot to death over 10 years. But the situation of the Park just got worse.
Today, Allan Savory regrets his decision. "Was the biggest mistake of my life", he says. WI will carry this guilt for my coffin". Driven by guilt, posed as personal goal the study of solutions to end the problem of desertification in the world.
And, after years of research, he has become adept to a solution that sounds unusual to traditional environmentalists' ears: the holistic grazing. In this technique, the herds are encouraged to graze as they did in the old days without human interference, and not confined just to a site.
In recent years, the idea began to gain strength and adherents and, recently, Savory presented the latest results of his work in a lecture at TED (the conference YouTube channel which has over 1.2 million views) and his theories have been replicated by more than 2500 farmers.
"There is no other more efficient technique to rescue areas in process of desertification", he says. And advocates "planting grass and trees, build irrigation systems, use machines to turn the soil artificially; none of this is as effective as let nature return to its natural course, which we interrupt".
The technique proposed by Savory is simple: ensure the safety and nutrition of a large numbers of animals in a particular pasture for a few days, but without preventing their movements. The biologist contends that that's how nature worked for millennia, until man trap animals and restrict its movements.
"The problem is not with the cattle, but rather in the way we teach animals to pasture, always in the same places", he says. According to him, animal paws help breaking the hardened soil, which increases water infiltration. What is really important is that they don't remain in the same place for too long, so they don't kill the rest of the vegetation.
Over two years, Savory grouped the cattle in compact blocks, moved the herds around different locations and analyzed plant growth. In the end of that period, he identified the increase on the quantity of minerals in the soil, fundamental for the plants diet: nitrogen, phosphorus, potassium, calcium and magnesium. More than that, he has seen fast growth in vegetation.
Savory already put his theory on the field in Africa, Australia and New Zealand, as well as in the North and South America, along with 10 thousand livestock farmers which, together, hold a 16 millions acre area. They use animals like, cows, bulls, buffalos, zebras, giraffes and elephants to recover the soil and prevent desertification.
Those who adopted this technique are extremely excited. The farmer Ivan Aguirre, from the Inmaculada Ranch, in the State of Sonora in northwestern Mexico. "After 15 years, my cattle is well fed, the plants are healthier and the number of dry areas is much smaller in relation to neighboring properties", he says.
At Dimbangombe, in Zimbabwe, a 2900 acres region of which was on its way to becoming a desert recorded an increase in the number of plants of four times in just five years. And, in Patagonia, the Argentine agronomist engineer Pablo Borreli says "the results began to appear very quickly. In two years, the vegetation began to recover". On his farm, 25000 sheep were put out to pasture. After a year, the vegetation volume increased by 50 percent.
Many scientists and researchers remain skeptical about Savory's technique. "It is surprising that his ideas are reflected as much. The theory is outdated and based on many concepts that do not count with the support of none serious environmentalist", says professor of ecosystems science David Briske, from the A&M University of Texas. "The Savory technique lets the cattle fatigued and thinner, which takes much of its commercial value".
In defense of Savory, the biologist Justin D. Derner, head of Development Research service of the United States Department of agriculture, says he doesn't understand the illness against the African. "After so many decades studying the global mechanisms of this great living organism that is the Earth, not even we still can say for sure what causes desertification", he says. "The work of Allan lacks scientific basis in many points, but still shows results".
The environmentalist and farmer Allan Savory, says he understand the criticism: "when I show that livestock integrated ecosystem can be good for the soil, it seems simplistic and too good to be true". It is thanks to the influence of his critics, says the biologist, that Governments are afraid to adopt the initiatives of the Institute Savory. The Brazil, for example, does not consider the sustainable use of grazing as an alternative to the desertification of the caatinga (a large area of White Woods in northeastern Brazil) and part of the cerrado, rather betting on projects for tankers, contours, forestry and livestock in the edges of the plantations.