Maximizing on-farm productivity of trees and agroforestry systems

Vision and goals

Our vision is well-managed, appropriately diverse tree cover in smallholder field, farm and landscape niches throughout Africa, Asia and Latin America contributing to food security, balanced diets, wealth creation and environmental integrity. The trees and associated interventions involved in getting them in place, will contribute directly and through knock-on interactive effects within livelihood systems, to lifting people out of poverty and improving equity in relation to gender, ethnicity, wealth and power.

Our theory of change involves a step change in agroforestry systems research from focussing on design of interventions at pilot sites to offering appropriate tree species and management options across large scaling domains.

Our key hypothesis is that drivers of adoption of agroforestry practices vary at fine scales. The drivers comprise an interdisciplinary range of contextual factors encompassing biophysical (soils, climate and predominant cropping patterns), economic (resource endowments, markets and livelihood composition) and social (knowledge, institutions and policies) context. This means that there are no silver bullets but rather a need to customise promising options to fit local circumstances across scaling domains and to support farmers in trying these out.

Doing this most effectively requires combining the most up to date science with local knowledge using approaches and tools that National Agricultural Research and Education Systems (NARES) and NGOs can readily implement. The most effective way to generate these tools and approaches and hence appropriate suites of agroforestry options is two pronged.

  • The first strand involves embedding our research ‘in’ development, adopting a co-learning paradigm through which best fit options (practices, extension approaches and institutional context) are generated and then progressively refined. This requires characterisation of variation in drivers of adoption across scaling domains, the systematic trial of a range of options across a range of variation in drivers appropriate to the scaling domain, coupled with participatory monitoring of their performance, and interpretation of these data to refine matching of options to sites and farmer circumstances. The results are practical tools and approaches that can be used by NARES and NGOs to support smallholder farmers in establishing and managing tree resources in their fields, farms and landscapes to reach our vision.

The first strand can only work at something close to the rotation length of the trees involved (or their time to maturity), which means that a second strand is required to predict longer term and larger scale impacts and explore alternative scenarios, including climate change.

  • The second strand involves developing a mechanistic understanding and models that encapsulate explanations about how trees impact overall productivity, crop yield, soil health, water regulation, other ecosystem services and overall livelihoods. Models allow performance from early phases of projects to be extrapolated to later phases and hence underpin investment decisions. Our key foci for this underpinning research revolve around how trees on the one hand impact the living soil and hence long term soil health and on the other, water productivity. The mechanistic understanding and modelling feeds back into selection of best-fit options in the first strand.

Our goals are three fold and follow organically from our theory of change. They are:

  1. to develop design principles for the incorporation of trees in fields, on farms and in various landscape niches, that improve productivity, environmental sustainability and equity;
  2. to develop mechanistic understanding and models that can explain larger scale and longer term impacts of trees, particularly on soil health, water productivity and livelihoods; and
  3. to combine these design principles and models in tools and approaches that enable development partners to generate and spread tree species and management options that improve food security, nutrition and wealth of smallholder farmers while sustaining key ecosystem functions.  

Research questions

  • What are the appropriate agroforestry-management options and their economic and ecological impacts on farming systems and household welfare?
  • How can multi-strata agroforestry systems best be managed for diversity, productivity, profitability and stability?
  • How are the costs and benefits of tree systems distributed among household members and social groups?
  • How can the ecosystem services, social utility and economic profitability of trees best be incorporated into mixed agroforestry systems?
  • What tools are required for identifying the right tree for the right place or smallholder populace? What tree integration models can optimize space and interactions among trees, crops and livestock?
  • What is the impact of land-tenure policies and practices on the development and spread of mixed agroforestry systems?
  • What are the impacts of external policies and institutional change on the adoptability, management and stability of agroforestry systems (e.g., technical recommendations, land and tree tenure, markets and policy)?