Can agroforestry and livestock-keeping support each other to build climate change resilience?
Planting trees and livestock-keeping might well go hand-in-hand in helping farmers both mitigate and adapt to a changing climate.
Livestock are often adapted to relatively marginal environments and can diversify rural production, promoting climate resilience. At the same time, trees can provide animal fodder and shelter, soil enrichment and other benefits to farmers, further supporting rural communities.
In East Africa, considerable success has already been achieved by dairy farmers growing the Latin American fodder shrub, calliandra (Calliandra calothyrsus). Along with other interventions in the dairy sector, cultivation of this protein-rich species has increased milk production in cows and goats, and therefore farmers’ incomes. There are now more than 200,000 farmers in the highlands of Kenya, Uganda, Tanzania and Rwanda growing the shrub.
A new working paper by scientists from the World Agroforestry Centre and the University of Copenhagen analyzes a wide range of issues relating to the future potential of trees as a source of livestock fodder for East Africa under climate change.
Currently there are 3 different livestock production systems in the region: pastoral, agro-pastoral and mixed farming. The type of livestock system which exists in an area is largely driven by the length of growing period (LGP) of annual crops. Pastoral systems mainly occur where there is a low LGP and mixed farming systems where the LGP is high. With climate change expected to decrease the LGP in coming years, cropping may decrease and farmers will need to improve pasture management and find new feed sources.
Trees may be able to supply feed more sustainably. Because they are able to draw water from deep in the soil and are more resilient to variable weather, they have the potential to provide fodder in dry conditions when shallow-rooted fodder is scarce.
“With weather patterns changing, farmers are looking to alternative ways of managing livestock and crops,” explains Ian Dawson, Associate Fellow with the World Agroforestry Centre and lead author of the new working paper. “There is untapped potential for trees to provide livestock fodder and other benefits to pastoralists, but a great deal of uncertainty remains.”
“Successful fodder trees need to display good growth, high feed value and be easy to source and supply,” says Sammy Carsan, [title] and co-author of the study. “The challenge lies in narrowing down to those fodder tree species which are genuinely useful for livestock keepers, and will continue to be so in the future.”
As weather patterns change, the geographic range where different animals can thrive and where particular trees will grow to provide fodder and other desired products is predicted to alter.
“We need to model existing and potential future geographic distributions for fodder species,” outlines Dawson. “We also need to better understand the climatic requirements of a wider range of indigenous trees that can be used for fodder, and promote those that are more climate resilient.”
So far, little has been done to exploit the genetic variation within African trees that would be useful for producing fodder, such as ease of digestion, protein content and productivity.
“We need more field trials on indigenous fodder trees and how they might respond to climate change, such as their drought tolerance and water use efficiency,” says Carsan.
A major obstacle to the uptake of fodder trees in the region to date has been poor seed and seedling systems. The study stresses the need for better quality fodder tree seed sources delivered to farmers by better supply systems and greater extension support.
Among the trees which have been identified as potentially suitable for fodder in East Africa are many which also have soil conservation / improvement properties that can support pasture and crop production. A number provide shade and ethno-veterinary (traditional) medicines for animals.
The working paper also discusses the climate change mitigation potential of fodder trees, and not just through the carbon stored in them. Livestock are responsible for an estimated 9 per cent of carbon dioxide emissions, 37 per cent of methane emissions and 65 per cent of nitrous oxide emissions. These emissions are linked to what animals eat and how animal feeds are produced. The use of tree fodders may provide routes away from high emission pathways, however full ‘life cycle’ analyses of emissions are required (from production to consumption of feeds).
Download the full paper:
Dawson IK, Carsan S, Franzel S, Kindt R, van Breugel P, Graudal L, Lillesø J-PB, Orwa C, Jamnadass R (2014). Agroforestry, livestock, fodder production and climate change adaptation and mitigation in East Africa: issues and options. ICRAF Working Paper No. 178. Nairobi, World Agroforestry Centre.