Context

Last update: 5 June 2013

Agroforestry is a set of land-use practices based on the simultaneous or sequential association of woody perennials including trees, shrubs, palms and bamboos with agricultural crops and/or pastures and animals.

For centuries it has been one of the traditional land-use practices on every continent, particularly in the tropics. Agroforestry can be considered as a promising sustainable agricultural model, provided production factors are better understood and more effectively controlled. Indeed, although agroforestry systems (AFS) have often been criticized for their lower agricultural production than monocultures, the contribution of AFS to global production and development in tropical zones is significant according to the large agricultural areas they occupy and the dependence of many rural societies on them.

AFS offer different assets when compared to monocultures, whose environmental and health impacts, and socio-economic vulnerability are likely to severely limit future progress. In general, agricultural systems are sources of ecosystem services, but also of “disservices” (loss of biodiversity, agrochemical pollution, nutrient runoff, sedimentation of waterways, greenhouse gas emissions) (Power, 2010). Compared to monocultures, AFS modify the balance between the provision of ecosystem services and “disservices”. Moreover, they are less input- and energy-intensive and combine ecological services and diversified production, while procuring land security. In AFS, provisioning services are impacted by modifications to the basic crop yield and by new productions that contribute to diversifying producer incomes, and to ensuring their food security. AFS contribute to regulating services, particularly by controlling the water cycle and water quality, regulating the climate by controlling GHG emissions and storing carbon. Also, depending on their composition, structure and management, AFS can make a great contribution to services that support the other services. These support services include: primary production, regulation of pests and diseases, soil conservation, regulation of nutrient cycling and the water cycle, biodiversity preservation. They also procure cultural services that benefit the community. Therefore AFS appear as a production mode that is potentially stable over time and resilient to environmental changes (climate change) and market globalisation. They thus seem to provide greater security than monocultures for the rural communities that practise them and for the consumers who depend on them. Agroforestry would therefore seem to be one of the solutions required in taking up the challenge for the ecological intensification of agro-ecosystems (producing more and better with few inputs). Thus, AFS possess major potential for improving productivity that has yet to be widely explored, notably in the field of:

  • optimizing tree/crop interactions for better use of natural ressources and crop diversification,
  • developing varieties adapted to agroforestry conditions,
  • pest and disease control with or without pesticides,
  • maintaining biodiversity that is of use to primary production and environmental services,
  • the vulnerability of systems in the face of disruptions.

The SAFSE project proposed here fits in with the current growing interest in agroforestry as an answer to the major challenges facing tropical countries: poverty, food insecurity, climate change, land degradation, loss of biodiversity.

Indeed, little is yet known about the mechanisms underlying the assumed resilience of AFS. One of the main reasons is the fact that they probably differ in nature and scope depending on whether one considers the resilience afforded by the facilitation/competition relationships in the biophysical system at the plot scale or that afforded by structural diversity and flexibility on a farm or territory scale, which is itself linked to socio-economic constraints. Another major reason lies in the fact that public agricultural policies in tropical zones have shown little consideration to date for agroforestry, due to the fact that it is traditional, often preferring to focus their actions on food or cash monocultures, or else ignoring the tree component in such systems. In the humid tropics, tree crop-based AFS are very widespread. There exists a whole complexity gradient in these systems, along with a management intensity gradient. In the dry regions of sub-Saharan Africa, tree and shrub parklands are also the basis of a food crop agriculture that is still particularly precarious. In these two regions, AFS exhibit contrasting dynamics and involve locally a wide range of stakeholders and practices in diverse contexts. It is this diversity that the SAFSE project intends to examine and conceptualize, by bringing together teams from CIRAD, IRD and their national partners with sound experience of these environments. The expected results should shed light on the choices of stakeholders and decision-makers in these regions between immediate food security, whose sustainability is undermined by high vulnerability to global changes, and food security over the longer term, through autonomous and diversified production contributing to increased resilience of the agrosystems and the societies that depend on them.

Last update: 5 June 2013