Permaculture instructor Andrew Millison journeys with the UN World Food Programme to the country of Niger in the African Sahel to see an innovative land recovery project within the Great Green Wall of Africa that is harvesting rainwater, increasing food security, and rehabilitating the ecosystem.
I think that was a joke, but I in case it isn’t: swaling (this kind of swaling) concentrates rainfall. It’s a neat feature of how water flows through soil. My question is, over time entropy will be working to flatten everything back out and fill the holes. As it rains, soil will erode back into the holes - maybe quicker that it takes for plant roots to establish and hold the bowl-shape. Large-scale, earth-mover-size projects make big swales that are more resistant to erosion. For such small swales to hold their shapes, I’d expect they’ll have to establish plants in the bowl first, which might be hard if it’s arid soil - they’ll have to port in water to get the surface plants established.
It all seems harder than just digging craters and planting a tree in the middle. But I’m pretty ignorant about all this - happy to hear from someone with experience in this area!
No experience in the area, but I watched the documentary on the UN project and there is a whole system to it: first the semi circular round bowls, planted with sorghum or some sort of hearty-food producing plant, then rows of crops with a ditch behind that, and trees planted on either side (or in front of it?). Anyway, the soil does erode but by then the landscape is pretty set and needs little maintenance. The great green wall is an amazing project for humanity.
Thank you!
https://youtu.be/4xls7K_xFBQ
FOUND IT!