A Tree That Enriches The Soil
Nairobi, Kenya – African farmers could triple yields by planting a type of acacia tree that sheds its nitrogen-rich leaves in time for the growing season alongside their crops. The fast-growing, hardy species, Faidherbia Albida, which has common names including Apple-Ring Acacia and Ana Tree, also has a wide range of other benefits, according to Dennis Garrity, director general of the World Agroforestry Centre in Nairobi, Kenya. “Besides organic fertilizer and livestock fodder for farmers, it also acts as a windbreak, provides wood for fuel and construction and cuts erosion by loosening the soil to absorb water during the rainy season,” he said at the 2nd World Congress of Agroforestry in Nairobi this week (24 August 2009).
Garrity added, “The tree becomes dormant and sheds its leaves during the early rainy season at the time when seeds need fertilizer and regrows them at the beginning of the dry season, so not competing with crops for light.” The acacia variety is already grown on farms in western Africa, as well as in Ethiopia, Malawi and Tanzania, but its use has been minimal in other parts of Africa.
Faidherbia Albida is one of the fastest growing indigenous trees from Africa to Australia. It is deciduous and can grow up to 30 m [100 ft] tall. It is one of the best drought-tolerant trees and it can survive occasional frost [up to 5 days per year]. In many arid African nations it is illegal to indiscriminately cut them down.
It is a valuable tree for game and domestic animals. It is mostly browsed by elephants, giraffe, kudu, nyala, and impala. This plant loses its leaves in summer, thus providing fodder for the animals during winter months. The leaves are nutritious, the seeds have high protein content and the pods are high in starch.
In addition to the obvious benefits that the Faidherbia Albida trees would provide, there is also the benefit of a variety of medicinal applications. The tree is used for the treatment of respiratory infections, for malaria and fevers. It is also useful in treating diarrhea and other digestive problems. The bark is used as an antiseptic in dental hygiene and its extract is employed in the treatment of toothache. The extract is also used to treat ocular infections in farm animals.
Despite 60 years of research and more than 700 scientific publications on Faidherbia Albida, few farmers — especially in parts of eastern and central Africa — know of its potential. The tree can thrive in a wide range of conditions and is suitable for planting across the continent. Garrity says the lack of knowledge about the acacia highlights a need for research agencies to find more effective ways to reach farmers.
Nobel Peace Prize winner Wangari Maathai, founder of the Green Belt Movement in Kenya, says that the lack of extension services that tap into agroforestry science from research institutions and universities and then pass information to smallholders is a great disservice to the quest for food security in Africa.