Scientists at the ICRAF World Agroforestry Centre have produced a paper that examines tree fodder in livestock systems.

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Although agroforestry, a sustainable farming approach focused on the reintroduction of trees into the agricultural landscape, is gaining ground around the world, formal research remains in its infancy. Even so, the approach received research funding under the new European budget, and is enjoying rapid growth in many countries including France where the area under agroforestry management has grown by 10,000 hectares in the past five years.

Often silvopastoral agroforestry applications are thought of as mainly providing shelter for animals and boosting access to nutrients and water for forage, though the practice can offer much more diverse benefits, ranging from a separate crop (for biomas or Christmas trees) to providing an extra source forage for stock from the trees themselves.

In fact, pollarding to source tree hay is thought to be one of the oldest agroforestry practices. Early farmers, having witnessed animals browsing on trees and shrubs, are likely to have cut off branches and stored them, preserving the nutrients in the leaves to feed livestock in months when food was scarce. This option would have been available to farmers using stone tools, long before the invention of equipment sophisticated enough to harvest grasses. It is thought, in some cases, to provide other benefits, including control of parasites.  

The ICRAF paper looks at the role of tree fodder in livestock systems and the growing of fodder for diversification of farm businesses in East Africa. The paper examines farmer-managed natural regeneration of trees and shrubs, cut-and-carry livestock feeding systems and the growth of fodder crops in agroforestry systems.

Impact of climate change

Its authors said that, given the potential for climate change to affect already dry regions, making some drier, whilst leading to higher rainfall in others, which could in turn exacerbate flooding and soil erosion, agroforestry presents perhaps the best solution for mitigating anthropogenic climate change and guarding farmers against its effects.  

The researchers pointed out that, given the forecast for the effect of climate change in East Africa, "Tree-fodders are considered an important response because trees with their deep root systems that can draw water from deep in the soil are more resilient to variability in weather patterns, and can provide fodder for longer than shallower-rooted plants in dry periods." This could also hold true in parts of Southern Europe, which are expected to become drier as climate change worsens.

In the face of threats from global warming, and given the importance of reconciling climate change mitigation efforts with the needs of local people, to feed growing populations and ensure small farmers have stable livelihoods, the researchers said better fodder tree stock, increased availability of a wide range of tree fodder species and enhanced extension services to support planting, propagation and more widespread agroforestry are all essential in East Africa.

The ICRAF scientists said that in most parts of Africa, climate change mitigation focuses on reforestation and forest protection, but that efforts to reduce deforestation often conflict with the need to expand agricultural production. As agriculture in Africa is dominated by smallholder farmers, food production and sustaining livelihoods must therefore also be a priority. Given these circumstances, they said, measures such as agroforestry that can mitigate the effects of climate change whilst improving food production should be embraced as quickly and fully as possible.

Dr. Cheikh Mbow, the paper's lead author, commented, "This mixture shows the role that agroforestry can play in addressing both climate mitigation and adaptation in primarily food-focused production systems of Africa." Speaking more generally, Dr Mbow added, "It has been demonstrated by science that if you develop agroforestry it has the potential to buffer the impact of climate change. For example, a farm with trees will suffer less to the impacts of climate change because it will absorb some of these impacts, so agroforestry is a good response to develop resilience of agrosystems to the challenges brought about by climate change."

Although the ICRAF research paper focused on applications of agroforestry and tree fodder in East Africa, the approach could be tailored to different local conditions and implemented much more widely, providing benefits and creating more sustainable, circular systems all over. In the Southern United States, silvopastoral agriculture has also taken off.

In the UK, the Silvopastoral National Network Experiment involved trees being incorporated into livestock systems at six sites around the country, although routine measurements have now stopped at most of the sites. However, though the approach has grown rapidly in France, thanks to state support, elsewhere in Europe, high costs and long growth periods have slowed uptake of agroforestry outside of research farms.   

Elsewhere, 'Tree hay' is still widely used, particularly in arid countries, due to the lack of available moisture from other sources during hot months. In drier regions and at higher altitudes in remote parts of Europe and elsewhere, tree foliage can still provide over 50 per cent of feed for ruminants.

The ICRAF paper can be read here