Zaï Soil Rehabilitation

As featured in the 2010 documentary The Man Who Stopped the Desert, Zaï pits (called Tassa in Niger) are a simple, but effective drylands soil rehabilitation strategy.

A practice indigenous to the arid Sahel strip, they were reintroduced and brought to prominence again in the 1980s by Yacouba Sawadogo, an activist and expert farmer from Burkina Faso. He modified the traditional design into the multi-functional model used today.

Zaï pits deal with the related problems of aridity, erosion, and soil compaction, particularly on difficult-to-cultivate sloped land: crusted land exhibiting these features is locally called “Zippelle.”

During the dry season, pits are dug 15-20cm deep, and 20-50cm wide, and earth from the pits is arranged in a semicircular formation on the lower grade of the slope, to increase water retention. Organic matter such as raw compost, plant matter, or manure is added to the pits, creating a depressed, moist, water-retentive, nutrient-rich cavity in which trees or crops can be planted. 

The raw compost in turn attracts termites, who burrow in the surrounding soil, loosening it to increase water and root penetration, and also digesting the raw organic matter in order to make the nutrients bioavailable to the plants.

Anschuetz et al. (2003)

Roose and Rodriguez (1990)

The World Bank reports that if done properly, this technique increase yields by 500%. [1] Combined with agroforestry strategies, like the planting of leguminous trees (traditionally, Acacia: see the “Great Green Wall”), it has the potential to reverse further soil erosion, compaction, desertification along the border of the Sahara.

Images: The Man Who Stopped the Desert, Chris Reij

h/t to ultrafacts

#soil science #arid #agroforestry #Africa


Since travelling into the Sahel region of Northern Western Africa (Mali, Niger, Libya, Algeria, Burkina Faso, Mauritania)  in 1999, French photographer Arnaud Contreras has been documenting the intersection of music and youth culture in these areas, as well as the juxtaposition of where Western influences meet local cultures and traditions, something seen in the music of bands like Tinariwen that combine sounds of the electric guitar with their own Malian musical heritage.

All this happening against the background of areas that have become highly susceptible to threats of terrorism, human trafficking, migration of undocumented persons, and the pressures on cultural and natural heritages from tourism, governmental authorities and other infringing groups. 


Senegal in 35mm Film - Part 1

35mm, Canon AE-1 Program, Kodak 400.

Senegal left me with a beautiful feeling. In the wake of befriending a hodge podge of people I met from all paths in this life, I could only come away with one of the best sensations I have had from a temporal time within a place, and amidst all those that make our world distinct. Senegal, with it’s wind swept terrain and endless Saharan dust, it’s Sahel landscape and rhythmically infused musical culture put a sensation over me that gives me the looming urge to return.

Sometimes it is nice to ditch all the heavy gear, walk around and shoot film that you can’t review until months later.

Here is Senegal in 35mm.

Photos by | Ozzie Hoppe

Sahel: a starving land

Today I found myself reading an article about the serious problems that afflict Africa’s Sahel region.

The columnist writes:

About 11 million people in the Sahel continue to suffer from severe food insecurity. The FAO reports that poor families have exhausted all the possible supplies of food and, waiting for the next harvest, they have to cope with high food prices. The U.N. agency has appealed to the international community to increase funding for aid to the most vulnerable populations in the  region South of the Sahara….

Wait a minute, this is terrible and the funds are certainly needed, but do we want to take a step back and see how the problem raised?

Probably many know that the Sahel is one of the regions in the world most affected by desertification, but perhaps there are few who know that this problem is not due solely to temperature increase, lack of rain and climate change, but also to mismanagement of the land by man. 

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