The story
Driving between farm fields during the rainy season in northern Ghana, it is hard not to miss spiny, white trees dotted across farmland. While all other trees are in leaf, this tree is bare. Growing around the tree, the crops are bigger, greener and are more abundant than in other fields. This is the faidherbia, or as many farmers call it, the “fertiliser” tree, because they can literally double their crop yield by growing it in their fields.
Faidherbia (Faidherbia albida, formally Acacia albida), the apple-ring acacia
- Habitat: Banks of seasonal and perennial rivers and streams on sandy alluvial soils or on flat land where Vertisols predominate; tolerates long droughts and temporary flooding
- Distribution: Africa, from South Africa north through eastern Africa to Sudan, Eritrea and on to Israel.
- Size: Grows to 25m – 35m at a fast rate
- Interest for agroforestry: nitrogen fixing, reverse phenology, livestock fodder
Faidherbia is a resilient tree that can grow in conditions as dry as 300mm/year, so it grows right up until the sahel. Yet in much of the landscape where Eco Restore works with farmers, faidherbia is not common. There is a fear from some farmers that planting it will turn their fertile lands into dry lands like the sahel – because that is where it grows. Moreover, faidherbia is a spiny tree with a nasty thorn. Even the 3 week old seedlings give a reason for our nursery manager to be careful. Some farmers don’t like it for this reason.
Eco Restore is working with a group of farmers to plant the resilient faidherbia and demonstrate the potential benefits. The tree is an interesting agroforestry species for these reasons:
Nitrogen fixing: Faidherbia, also known as the “Fertiliser tree”, is a nitrogen fixing tree. Through mycorrhizal relationships, the tree releases nitrogen into the soil in a way that plants can access it. In West Africa this is extremely important as improving soil fertility is a food security issue.
Reverse phenology: Faidherbia trees grow leaves during the dry season and shed them at the beginning of the wet (in a process called reverse phenology). The leaves provide a layer of mulch just before farmers start seeding their fields. Farmers can plant faidherbia in the middle of their fields and grow crops under clear skies. In addition, cattle gather under the shade of faidherbia trees during the dry season. Not only does this keep livestock cool in hot temperature, but their frequent visits during the dry season enriches the soil with manure.
Improve soil fertility and double crop yield: Growing faidherbia is a great way to improve soil fertility. Farmers report doubling or tripling the yield of their crops when planting around Faidherbia trees.
Livestock fodder: Faidherbia trees are a source of livestock fodder in the dry season. The pods are high in nutritional value and cattle love them. They even fight each other for the pods when farmers prune trees. Pods are sold at local markets as an orange pod for zero grazing livestock. When we stock up our nursery, we buy pods from the market.
Wildlife: Flowers profusely just at the beginning of the dry season and is a very important bee fodder. Possibility to benefit birdlife by growing as a thicket hedgerow
Other uses: building poles, fencing, cattle pence, wood is easy to work, tool handles, bark is used in the tanning of leather
Planting experience: In 2020, Eco Restore worked with farmers to plant 330 faidherbia seedlings. Seedlings were recorded as having a 90% survival rate.
Read more about faidherbia:
Faidherbia trees grow leaves during the dry season and shed them at the beginning of the wet in a process called reverse phenology (Photo credit: Tom Lovett)
Faidherbia trees provide essential shade during the hot, dry season (Photo credit: Peter Lovett)
Cattle gather under the faidherbia shade and further fertilise the soil (Photo credit: Peter Lovett)
Cattle graze on faidherbia as children collect pods (Photo credit: Peter Lovett)
A faidherbia tree in fruit (Photo credit: Peter Lovett)
Freshly collected faidherbia pods (Photo credit: Peter Lovett)
Faidherbia seedlings growing in the Eco Restore tree nursery (Photo credit: Tom Lovett)
Faidherbia and shea seedlings being transported for planting (Photo credit: Peter Lovett)
