Improving agroforestry and silvopastoral systems in the Amazon

Identifying and testing Inga species to promote agroforestry and silvopastoral systems, supporting sustainable use, conservation of biodiversity and increased income for farmers.

Close up of Inga

Tropical forest soils in the Amazon and many other parts of Latin America are generally nutrient-poor and unsuited to long-term agricultural use. Land converted to agriculture by cutting and burning natural vegetation tends to remain productive for only a few years, necessitating continual advance of the agricultural frontier, with accompanying deforestation, and generating situations of food insecurity and poverty.

Agroforestry and silvopastoral systems, which incorporate trees into crop and livestock systems, have been shown to make a dramatic impact on the maintenance and restoration of long-term productivity in agricultural landscapes, including degraded and abandoned land, and are well suited to use by poor rural smallholders. They can provide major benefits through enhanced livelihoods and food security, as well as to local economies.

Inga is a diverse genus of trees from the legume family, found across the humid tropics of Latin America. These fast-growing trees are able to capture nitrogen from the atmosphere and fertilize the soil around them. They can be grown in poor, degraded soils, out-competing weeds and invasive species. The value of native trees, including Inga, within agroforestry systems, where they are planted to provide a nurturing environment for crops, has been amply demonstrated by a number of projects, and is gaining momentum.

Emerging techniques in genetics offer the potential for rapid identification of species and genotypes of Inga with similar ecological characteristics, thus facilitating fast-tracking of appropriate candidates into field trials and ultimately into more productive landscapes.

The project will apply state-of-the-art genetic approaches to complete a thorough analysis of the genus, focusing primarily on species in the Brazilian Amazon, identifying the most suitable species for agroforestry and silvo-pastoral systems. Critically, this selection of species will be done in consultation with stakeholders and smallholders, to ensure uptake and use of the selected species.

Targeted field collection of tissue specimens and seeds from these species will support ongoing genetic research, and will be used to establish early-stage field trials in Mato Grosso (southern Amazon), both in controlled contexts and in agroforest systems. These will be monitored to assess a range of characters including growth rate, biomass and tree form, all of which are important indicators of their suitability. Longer-term monitoring, using protocols developed by the project, will provide further indication of their potential value within these systems.

The project will be delivered in Brazil through collaborative partnerships between UK and Brazilian scientists. It aims to develop and demonstrate the effectiveness of a methodological approach that can form the basis for improved agroforestry and silvopastoral systems across Latin America. In the course of the project, the team will build a network of scientists and practitioners within Brazil and across other Latin American countries, facilitating the development of further research in this field and communicating its findings to a range of academics, practitioners of agroforestry and silvo-pastoral systems and the lay public, in both Latin America and the UK.

Project lead

Dr William Milliken

The principal short- to medium-term impact of this project will be establishment of the scientific framework and collaborative partnerships. These are necessary for the development of agroforest and silvopastoral systems for crop and livestock production that will contribute to more sustainable and productive agricultural landscapes in the humid Neotropics.

The project will leave a lasting legacy including:

  • increased awareness, knowledge and uptake among scientists, practitioners and policy-makers of Inga systems;
  • greatly improved knowledge of appropriate species and varieties of Inga for application within this context, achieved through the application of advanced molecular techniques and field trials supporting site-appropriate selection and breeding;
  • new partnerships, alliances and technical approaches for further research and development in the region; and
  • enhanced capacity for applied genomic research in Brazil applicable to agroforestry development and improvement more broadly.

In the longer term, in addition to future research built on the foundations of the project, the ultimate beneficiaries of our work will be rural communities in lower-middle income countries in Latin America.

Via the greater resilience of agroforest and silvopastoral systems in times of climatic change and population growth, these communities can benefit from reduced poverty, improved food security, and reduced pressure on natural vegetation and biodiversity through conversion to agriculture. The outcomes from the project will therefore directly support Brazil in delivery of its commitments to the Convention on Biological Diversity and to the United Nations Sustainable Development Goals.

  • University of Exeter, UK 
  • Instituto Ouro Verde, Brazil 
  • University of Mato Grosso (Alta Floresta), Brazil
  • University of Edinburgh, UK 
  • Royal Botanic Garden Edinburgh, UK
  • Instituto Nacional de Pesquisas na Amazonia (INPA), Brazil