Unique acacia tree could nourish soils in Africa

Washington, August 25 (ANI): In a new research, scientists have said that a type of acacia tree with an unusual growth habit, which is unlike virtually all other trees, holds particular promise for farmers in Africa as a free source of nitrogen for their soils that could last generations.

With its nitrogen-fixing qualities, the tall, long-lived acacia tree, Faidherbia albida could limit the use of fertilizers; provide fodder for livestock, wood for construction and fuel wood, and medicine through its bark, as well as windbreaks and erosion control to farmers across sub-Saharan Africa.

According to scientists, the tree illustrates the benefits of growing trees on farms and is adapted to an incredibly wide array of climates and soils from the deserts to the humid tropics.

"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," said Dennis Garrity, Director General of the World Agroforestry Centre.

"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," he added.

The Faidherbia acacia tree has the quality of "reverse leaf phenology," which drives the tree to go dormant and shed its nitrogen-rich leaves during the early rainy season - when seeds are being planted and need the nitrogen - and then to re-grow its leaves when the dry season begins and crops are dormant.

This makes it highly compatible with food crops because it does not compete with them for light-only the bare branches of the tree's canopy spread overhead while crops grow to maturity.

Their leaves and pods provide a crucial source of fodder in the dry season for livestock when other plants have dried up.

The unique acacia tree is a frequent component of farming systems of Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, and Ethiopia, and in parts of northern Ghana, northern Nigeria, and northern Cameroon.

The tree is growing on over 4.8 million hectares of land in Niger. Half a million farmers in Malawi and in the southern highlands of Tanzania grow the tree on their maize fields.

In Malawi, maize yields were increased up to 280 percent in the zone under the tree canopy compared with the zone outside the tree canopy.

In Zambia, recent unpublished observations showed that unfertilized maize yields in the vicinity of the Faidherbia trees averaged 4.1 tonnes per hectare, compared to 1.3 tonnes nearby but beyond the tree canopy. (ANI)