Creating Sustainable Livelihoods and Capturing Carbon

Inga Foundation
Monday, 1st June 2020

The Inga Foundation are teaching farmers healing, productive and profitable methods of farming to replace the traditional 'slash and burn' system.

Slash-and-burn subsistence agriculture has fed millions of families over past centuries; today it maintains some 250-300 million descendant families in poverty; and its widespread failure is an underlying cause of rural-urban migration in the tropics. The consumptive process by which forest cover is converted to invasive grassland, over vast swathes of former tropical forest, is estimated to be contributing between 1 and 2 billion tonnes of carbon (C) annually to the atmosphere; more than all global transport combined. Neither this process, nor the families' attempts to feed themselves, are sustainable today. Climatic violence is adding an additional dimension of insecurity into their lives.

Inga Foundation's Land for Life project in Central America is working with communities to provide alternatives to this destructive method.

The project aims to:

  • An end to the destruction of the World's remaining primary and secondary rainforests by slash-and-burn agriculture. 
  • An end to the food-insecurity and poverty that is driving that destruction; and to the socially destructive rural-urban migration that results from slash-and-burn's failure to sustain subsistence agriculture in these environments.
  • To introduce and facilitate the adoption of a proven, minimal-input rural livelihood with families who are presently enduring a precarious (and failing) struggle for subsistence by slash-and-burn.
  • To promote and further to expand the highly encouraging beginnings of a grass-roots revolution in subsistence agriculture in the World's rainforest regions. 
  • Actively to promote the reforestation of those areas of the family holding no longer needed for slash-and-burn.

By introducing inga alley-cropping, an agroforestry technique, this new model allows farmers to yield food security and a reliable cash-crop income in a low-input, debt-free and scientifically-proven system.

The Guama Model ('Guama' is the local name for trees of the genus Inga in Honduras) results from over 25 years' research and development, starting with 16 years of research projects led by Cambridge University. Inga Foundation (IF) was founded to implement the Cambridge work.

What is alley-cropping? 

Inga alley-cropping is a system of deep mulching using pruned green leaves from the trees which are contour-planted in hedgerows. In Honduras, the trees are pruned annually, as here, and left to recover their canopy after the maize is cropped. It has proved itself capable of achieving food-security in basic-grains for the family, upon a permanent plot which can be located near their dwelling. The system produces a favourite firewood for the kitchen and virtually eliminates the need for weed-control. Additional plots enable the whole family to be involved in their own cash-crop economy; located, perhaps for the first time, on their own doorstep. Weed-control is achieved, firstly, by shading under the dense Inga canopy and, secondly by smothering under the resistant mulch.

Inga is a genus of nitrogen-fixing legume trees originating in the Amazon Basin and containing over 300 species. The species shown here (I. edulis) is tolerant of acid soils and is very efficient at recycling essential plant nutrients as well as the nitrogen fixed in its root nodules. It produces foliage that only decomposes slowly thus giving vital physical protection to the essential surface soil layers from the erosive power of heavy rain and from overheating by direct exposure to solar radiation.

The system develops within about two years and can be maintained permanently thereafter. Small quantities of rock-phosphate are needed to replace the phosphorous removed in the grain; and, in very degraded soils, the trees need supplementary calcium, potasium and magnesium minerals to start the process of site-capture from the invasive grasses that typically dominate such sites.

Inga alley-cropping is introduced to communities by demonstration and farmer-to-farmer extension. Demonstration farms and plots; backed by extension support over the long adoption period (2-3 years) provided by local farmers who are employed by Inga Foundation and who are already successfully implementing the system.


Present operations

Since 2012 we have been able to employ a Forester and an Agronomist to oversee the program of extension work with families in both catchments. Because of limited availability of Inga seed until 2014, together with limited funds to place 'boots upon the ground', we estimated a recruitment rate of 40 families per year; up to about 200 by the end of 2016. This target was passed in mid-2015 amid a growing demand for the system as word spread around the valleys.

A most welcome grant from The Funding Network-SFG enabled 8 heavtres of land to be bought at Las Flores in the Cuero valley. Now (2020) this demonstration/teaching facility is the living heart of the whole operation. 3.5 hectares of Inga alleys and 3.5 hectares of inga seed orchards are now in full production and have transformed the farm's location. We have also established a large tree nursery and plant propagation unit. During 2016-2017 we were able to add a further 4 hectares which are being reforested as an arboretum and future seed-source for endangered tree species.

The Guama Model: an integrated rural livelihood – replicable and debt-free

A single hectare (ha.) has been found sufficient to provide the food security for a family to benefit from a sustainable low-input rural livelihood. The Guama model was developed with local non-Governmental (NGO) partners alongside Honduran farmers to provide typically: 

  • 1-2 ha. of Inga alley-cropped basic grains; (e.g. maize, beans)
  • 1-2 ha. of Inga alley-cropped cash-crop cultivars (e.g. vanilla, black pepper, turmeric);
  • 1-2 ha. of low-maintenance fruit trees, (e.g. cacao, citrus);
  • 2-4 ha. of formerly degraded land for reforestation and carbon-capture.

The model assumes a holding of about 8ha. and is completely flexible; a family can adopt any component, or combination of components, on any area, that it wishes. 

The diagram below illustrates the model in the landscape. Carbon-emission avoidance and capture of atmospheric carbon (C) have been estimated for the whole program; and annual data for one family adopting the model are included here; data cover the first 12 years following adoption.

Since 2012, IF's Land for Life Program, now (July 2019) involves around 300 families; the program has sequestered over 40,000 tonnes of atmospheric carbon; a figure that will reach 108,000 tons by the end of 2013:




A wide diversity of cash-crop cultivars have already been successfully proven in inga alley-cropping during the Cambridge projects. The mulching system eliminates the need for physical or chemical weed-control and provides the biological conditions for reliable cash-crop production. Whilst yields per hectare might not match those of conventional plantations, an acceptable crop can be produced on minimal external costs. The investment derives from the family's own effort and care; not from crippling external finance. Broad strategy is to produce those cash crops that already have a local market and are fitted to the logistics of reaching those markets in marketable condition. Black pepper, curcuma, maracuyá (Passiflora sp.) and vanilla are good examples.


Vanilla raceme

The long-term objective is to establish with the families the basis for the production, quality control and local marketing of cash crops; to the point at which economies-of-scale begin to exert a positive influence on both logistics and the families' collective bargaining power.

This phase is seen as mainly occupying the later five-year phase of the 10-year overall plan. Alley-cropping for food-security and the slow replacement of slash-and-burn have taken priority during the first five years.

Wider Strategy - projects as models for the Central American Region

Inga Foundation's strategy is to concentrate effort and resources into the area where we are presently established. The overall objective is that enough families can be seen successfully implementing and replicating the Guama Model such that it will begin to replicate itself spontaneously. The whole area may serve as a model of resilient best-practice for the whole humid Central American/Caribbean region in a time of climate-change. IF's role in teaching these techniques has already attracted national (Honduran Gov'nt) and regional attention (PARLACEN and IUCN).

Inga Foundation ( was one of the 20 finalists for the 2019 Permaculture Magazine Prize.

Useful links

Permaculture Magazine launches third year of prize

How the garden works in educating children

Bioremediation and regeneration in oil-damaged Ecuador