Theme 2: Sustainable and diversified AgroForestry Systems (AFS)


How to design AFS adapted to specific constraints and potentials?
How can we achieve competitive, sustainable and diversified AFS management strategies (including adaptation to sub-optimal conditions and long-term environmental change)?


The objective of this theme is the design, in collaboration with farmers, of competitive, sustainable management strategies for AFS that are adapted to local constraints and potentials. The research and development efforts will focus on the complementarities and facilitation between perennial crops, shade trees and other associated species for greater productivity, quality and economic viability.

One of the main tasks will be to optimize biophysical tree-crop interactions in order to reduce the incidence of limiting factors (e.g., high temperature, drought, pests and diseases, depleted fertility), as well as competition for light, water and nutrients, under the real conditions found in commercial farms of different management intensities. Another main task will be to determine which diversification options have commercial potential. Special attention will be devoted to the development of new tools useful for AFS design: e.g. ecological models to analyze the trade-offs such as SVAT models; sustainability indicators; the relationships between production and environmental quality; and participatory methodologies to modify complex systems successfully.

The partners of the PCP have a long history of joint research on AFS biophysical issues. Some of the recent findings indicate that shade in coffee AFS results in more stable production and improved coffee quality when compared to coffee monocultures. The inputs of nitrogen (N) through the association with leguminous shade trees and the potential beneficial effect of this input on coffee production have been quantified for diverse pruning schemes, site and management conditions. Biomass production and soil organic matter can be increased in some coffee and cacao AFS. In cacao AFS, the timber component is presently poorly exploited, although the annual increments can be high. In contrast, sales of timber and fuel wood can account for a significant part of coffee farmers’ revenues.

Other research activities of the partners, although out of the scope of this platform, will be useful for the design of improved AFS; e.g., their coffee and cacao genetic improvement programmes. A key challenge is how to integrate all the existing and new information into tools that can be used to design AFS that meet the demands of the stakeholders while meeting high standards in terms of conservation of natural resources. This integration will also allow us to identify knowledge gaps that need to be filled to be able to design even better AFS.

RESEARCH AND DEVELOPMENT ACTIVITIES

  • Studies of the physiology of coffee and cacao at the scale of branch, fruit, roots, plants and plantations: e.g. Carbon (C) and nutrient acquisition / allocation (including tracers); modeling water balances; and C, N and energy budgets.
  • Development and validation, in various ecological and management conditions, of plot level AFS models for the optimization of light, nutrient and water use to design sustainable coffee and cacao plantations; e.g., compared to monocultures, the resilience of AFS to economic and environmental risk factors such as climate change.
  • Identification and domestication of native fruit tree species, found in traditional coffee and cacao shade strata, which have commercial potential.
  • Evaluation of the potential and development of best agricultural/forestry practices to produce quality timber in coffee and cacao AFS.
  • Development and validation, for various ecological conditions, of models and decision-making tools on the incidence of pests and diseases with respect to shade management and other agricultural practices in AFS.
  • Development of expert models to illustrate the performance of potential tree-crop combinations for different site conditions and the possible responses to long-term environmental changes, considering different bio-physical interactions, environmental conditions and management options.

WHO IS INVOLVED?

Clementine ALLINNE, agroecologist, CIRAD [email]
Sanjeeb BATTHARAI, PhD student, models and ES at landscape scale [email]
Tamara BENJAMIN, agronomist, CATIE and Purdue U. [email]
Jayne CROZIER, microbiologist, CABI [email]
Elias DE MELO
, coffee agronomist, CATIE [email]
Louise MEYLAN, PhD student, CIRAD [email]
Maria PADOVAN, PhD student, coffee hybrids and climate change [email]
Bruno RAPIDEL, agronomist and model user, CIRAD [email] [personal website] [publications]
Eduardo SOMARRIBA, agroforester, CATIE [email]
Charles STAVER, agronomist, Bioversity [email]
Philippe TIXIER, trophic webs and banana, CIRAD [email]