Growers in the semi-arid regions of the Great Plains aren’t the only ones trying to harvest moisture.
A colleague sent me a very interesting article at Smithsonian.com about the success farmers in Niger are having using simple land management techniques to slow the intrusion of desertification and improve farm productivity.
The original idea, years ago, was to plant a 4,000-mile wall of trees across the Sahel, a 3,360-mile belt stretching across the southern edge of the Sahara. Rainfall is only 4-24 inches per year and droughts are frequent.
Farmers in the Sahel had learned from French colonists to clear land for agriculture and keep crops separate from trees. Under French colonial law and new laws that countries adopted after independence,Smithsonian says, any trees on a farmer's property belonged to the government.
Farmers who cut down a tree for fuel would be threatened with jail. The idea was to preserve forests, but it had the opposite effect — there was a disincentive to have a tree. Decades of declining tree shelter caused topsoil to dry up and blow, and rainfall ran off instead of soaking into cropland. Water levels in wells were dropping by 3 feet per year, at one point.
The “tree wall” plan was doomed due to a lack of funding, unoccupied stretches of desert and other issues. But even the talk of change sprouted another idea: that farmers ought to be preserving trees that sprouted on their land and covering more of the ground, rather than clearing fields and tolerating bare, blowing soils.
The magazine says innovative farmers in the Burkina Faso area of Niger built zai, a grid of deep planting pits across rock-hard plots of land that enhanced water infiltration and retention during dry periods. They also built stone barriers around fields to contain runoff and increase infiltration from rain.
Gray Tappan, a geographer with the U.S. Geological Survey’s West Africa Land Use and Land Cover Trends Project, discovered the re-greening mostly stopped at the southern border with Nigeria, where there is more rainfall, which was counterintuitive, Tappan says. More precipitation should mean more vegetation.
"It wasn't about rainfall," he told the magazine. "It was absolutely about farmers changing the way they manage trees and their perception of the trees."
It isn’t too hard to see some parallels with the tree clearing, bare soils, droughts, and land overuse in the Sahel and problems we’re facing with some of our own agricultural lands in the Great Plains.
There’s no disputing the viability of the Ogallala aquifer, in some states, is in danger that is due not just to droughts, but to poor soil management and inefficient irrigation.
There are still millions of acres of cotton being tilled every year due to myths passed down through the generations like, ‘We need to work that land so it can take a rain.’ And negative perceptions about cover crops are slowing their adoption, even as many fields and pastures are in desperate need of regeneration.
Surely, if farmers facing a creeping desert in Niger can devise a plan to harvest moisture, care for the soil and improve production of food and fuel, we can increase the adoption of these practices here, too.
Perceptions are a funny thing, aren’t they?