West African Shrub Initiative (WASI)

Desert encroachment in the Sahel Shrubs long tap root Millet no shrub on left, millet with shrub on right

The Situation

In the Sahel

• The Sahel is a fragile semi-arid ecosystem with long-standing concerns about desertification,
chronic poverty, and food shortages.

• Rural agricultural landscapes are under threat from increasing rural population and intensive cropping and over grazing by livestock.

• Degraded soils and landscapes are decreasing crop productivity and increasing vulnerability to global climate change

• Drought and water stressed crops are constant and major challenges

• Farmers are risk averse with few biological options in the semi-arid environment

• Farmers destructively burn woody shrub debris.


The Solution

Shrub Intercropping

• Native woody shrubs (Guiera senegalensis and Piliostigma reticulatum) coexist in farmers’ fields, but agronomic benefits are unrecognized

• Implement shrub density optimized systems in farmers fields.

• Adopt non-thermal shrub residue management to provide organic inputs and nutrients to soils using a local resource.


The Benefits

Scientifically Validated

• Increased yields

• C sequestration

• Improved soil quality

• Crop drought stress reduction

• Promotion of beneficial bacteria and mycorrhizal fungi for improved crop growth and health

• Shrubs perform hydraulic of water from wet subsoil to dry surface soils to assist crops

• Shrubs increase groundwater recharge during rainy season

• These beneficial effects have been scientifically validated in 24+ refereed journal articles.


Richard Dick presenting "Intercropped Woody Species in the Sahel to Resist Drought" at InterDrought-V Conference in Hyderabad, India February 2017.