Acacia Tree Could Nourish Soils and Life in Africa

In the 2nd World Congress of Agroforestry, Director General Dennis Garrity of ICRAF (World Agroforestry Centre), host of the Congress said that, "Growing the right tree in the right place on farms in sub-Saharan Africa-and worldwide- has the potential to slow climate change, feed more people, and protect the environment. This tree, as a source of free, organic nitrogen, is an example of that. There are many other examples of solutions to African farming that exist here already."

The tree he is referring to is the tall, long-lived acacia tree Faidherbia albida, known for its nitrogen-fixing qualities that could limit the use of fertilizers; provide fodder for livestock, wood for construction and fuel, and medicine through its bark as well as windbreaks and erosion control to farmers across the sub-Saharan Africa. The tree is also widely adapted to a wide array of climates and soils from the deserts to the humid tropics. 

With African farms being severely degraded and African farmers applying only 10 percent of soil nutrients used in the rest of the world, planting acacia tree is an important option. The tree goes dormant and shed its nitrogen-rich leaves during the early rainy that coincides with the planting season. Field crops planted around the trees are fertilized during their entire growing season, and leaves and pods provide fodder for livestock in the dry season  when the plants have dried up. In many African countries, the tree is a frequent component of farming systems.

Yield increases have been documented in unfertilized millets grown under the tree in West Africa, for sorghum in Ethiopia, other parts of Africa, and in India, in addition to groundnuts and cotton. Often, millet and sorghum exhibit no further response to artificial fertilizers beyond that provided by the tree's leaf fall.

See the report at:  http://www.worldagroforestry.org/af/index.php