From the US and China to Kenya, human efforts to preserve soil are proving incompatible with increasingly extreme weather conditions
In America’s dusty corn belt this spring, the earth was drowning. China’s Yangtze River Basin is dry. Farmers in both places are fighting an almost losing battle to save the soil that produces the food we eat. From the United States and China to Kenya, human efforts to conserve soil are proving incompatible with increasingly extreme weather conditions that are damaging the living system and depleting its ability to produce food, Reuters wrote after interviews with dozens of farmers, scientists and other soil specialists. .
Soil erosion could lead to a 10 percent loss in global crop production by 2050, according to the UN’s Food and Agriculture Organization (FAO). With the world population projected to grow by a fifth to nearly 10 billion by then, malnutrition and hunger will affect more and more people.
Few places are in deeper crisis than the grasslands of northern Kenya, where an ever-deepening drought has stripped the land of vegetation, exposing the soil to damage and confounding efforts to adapt agricultural practices.
“The soil left there is very vulnerable, like the Earth’s skin that doesn’t wear clothes while the sun is burning,” said Leigh Ann Winowiecki, a soil scientist in Nairobi at CIFOR-ICRAF, a research center on the benefits of trees to people and the landscape.
Fake rain: the icing on the cake
UN scientists say it can take up to 1,000 years for nature to produce 2-3 cm of soil, making its conservation critical.
Plants grow by absorbing sunlight and carbon dioxide. They transport carbon into the soil, feeding microorganisms that in turn create the conditions for more plants to grow.
Extreme weather conditions, some caused by climate change, not only damage crops but also erode soil and deplete nutrients such as carbon, nitrogen and phosphorus from the complex ecosystem, experts say.
This leads to land degradation – a reduction in its ability to support plant life, and hence animal and human life.
A third of the world’s total land area has already been degraded by erosion, nutrient depletion or other means, according to the United Nations.
Ronald Vargas, a soil scientist and secretary of FAO’s Global Soil Partnership, said extreme weather conditions are accelerating soil degradation that has already begun through deforestation, overgrazing by livestock and improper use of fertilizers.
“Land degradation is a vicious cycle. Once you’ve degraded the soils and bad weather events happen, then there are very bad secondary consequences,” Vargas explained.
Regarding the FAO’s projected losses in global crop production, he added that this 10 percent represents a real problem for food security.
Engineering the rain
The American Midwest, parched for rain this summer, is actually getting wetter with time.
Rainstorms over three days in mid-May washed away up to three tons of dirt per acre in two dozen Minnesota counties, according to data from the Daily Erosion Project, an Iowa State University initiative to assess soil loss.
Rachel Schatman, an assistant professor of sustainable agriculture at the University of Maine, said the U.S. Midwest and Northeast are particularly vulnerable to soil erosion because they receive more extreme amounts of rain than normal, a trend expected to continue through the end of the century.
In the Yangtze River basin, wetter weather would be welcome. The region’s agricultural belts, stretching from Sichuan in the southwest to Shanghai on the east coast, received 40 percent less rainfall than normal this summer and were baked by record high temperatures.
Liu Ziyu, an official at China’s water ministry, said in August that a third of the soil in six key agricultural provinces along the upper and middle reaches of the Yangtze was drier than optimal as a result of the drought. In about a tenth of the rural counties in these provinces, the soil suffers from “severe water depletion”.
China’s cloud seeding program has offered some relief, with 211 operations launched in August alone to bring rain over 1.45 million square kilometers of parched farmland, but experts say it is not a long-term solution.
Likewise, other measures, such as digging thousands of new wells and encouraging farmers to switch crops to increase yields, have had limited impact.
Farmers around the shrinking Poyang Lake in Jiangxi Province told Reuters that all types of crops were severely underdeveloped as a result of the lack of rainfall. Hu Baolin from Xinyao Village said his canola hasn’t even flowered and his pomelo fruit is a third of its usual size.
Residents of Jiangxi’s Hukou agricultural district said many sesame, corn, sweet potato and cotton plantations had dried up.
Some experts are optimistic that the world can turn away from the danger, at least in some places.
FAO produced an action plan this year that seeks to improve and maintain the health of 50 percent of global soils by 2030, adopting practices such as crop rotation and agroforestry, a land-use system that plants trees in and around crops and pastures.
Christine Morgan, chief science officer at the North Carolina-based Soil Health Institute, said soils can regenerate if farmers apply better methods more widely. “We always think that something new will save us, but we really need to change our behavior,” commented Morgan.
Options include no-till to reduce erosion and planting off-season cover crops to prevent erosion and nutrient loss. The practices are used on just 25 percent and 4 percent of U.S. farmland, respectively, according to BMO Capital Markets estimates, which say the major overhaul of cropping systems has created upfront costs for farmers, with losses of yield in the first years.
In Kenya, however, the damage is horrendous.
“The soil was never so sandy when I was young,” said Malian Lekopir, 50, who raises cattle and goats in the Samburu area. He remembers the times when the place was inhabited by animals, but now they are all gone and the streams have dried up.
Indeed, the land has dried up in the country, where prolonged droughts have become more common since 2000, with the current one the worst in four decades.
More than 60 percent of the country’s total land is considered severely degraded and more than 27 percent very severely degraded, according to Kenya’s environment ministry, taking into account factors such as vegetation cover and its ability to resist erosion. This is despite efforts by green groups to encourage farmers to use no-till or minimal-till agriculture and agroforestry.
None of the children playing in Lecopyre’s village in northern Kenya remember a real rainy season. They are used to herding camels and avoiding the growing network of dusty ravines, none of which existed during the farmer’s youth.
The drought has made the water sources this village relies on increasingly stagnant and the children sicker, Lecopyre said. To keep the remaining cattle and goats alive, herders often have to walk hundreds of miles in search of water or pasture.
Grass has disappeared from much of Kenya’s vast grasslands, leaving the land vulnerable to future compaction or erosion, explained CIFOR-ICRAF soil scientist Winowiecki.
So much soil has eroded in Kenya, India and many other places around the world that the earth’s seed bank – grass seeds ready to germinate after it rains – has also been depleted, meaning restoring some areas will require manual re- seeding, commented Thor-Gunnar Wagen, Chief Scientist of CIFOR-ICRAF.
“The whole system is at a tipping point. Climate change is only accelerating all of this,” he concluded.