Slash & Burn destroys rainforests sending CO2 into the atmosphere.Inga Alley Cropping is the sustainible solution for tropical family farms.



Slash and Burn is a subsistence farming method used by millions of families in the tropics. Annually, Slash and Burn contributes around two billion tons of carbon to the atmosphere -an amount greater than all global transport combined.Families cut down and burn a patch of forest in order to create an area of fertile soil on which they can grow their food. However, the soil fertility doesn’t last. Once cleared of trees and exposed to the strong tropical climate, the bare soil is rapidly stripped of nutrients. The first year, Slash and Burn generally gives a good crop, the next year less so and, by the third year, crops often fail completely. This crop failure and subsequent erosion forces families who depend on Slash and Burn to keep clearing fresh areas of rainforest every few years just to survive.

Inga Alley Cropping is the revolutionary alternative to Slash and Burn. Developed by Inga Foundation’s Director, Mike Hands, in partnership with Cambridge University, Inga Alley Cropping is based on over a decade of research on agroforestry systems. Of the different potential options investigated by Mike Hands, the only sustainable system to emerge from years of scientific research was Inga's system of Alley Cropping, which uses nitrogen-fixing tree species from the genus Inga. The Inga trees maintain soil fertility and good harvests year after year, breaking the cycle of Slash and Burn and allowing families to gain long-term food security on one piece of land. Inga Alleys out-compete the aggressive invasive weeds which dominate the farmers' plots, saving  weeding. In their 2nd year, the pruned Inga trees' foliage & trunk provides mulch for the Alley & firewood for the families' kitchens-again saving native trees from being harvested. This closed system is a revolutionary cycle--sustainable, organic food for the families, cash crops like pepper & pineapple--all grown organically. A system which also protects water sources, reefs, & prevents erosion.

What are the key outcomes and impact of your solution?

Once the Inga Alleys have developed (the nursery trees are planted and growing in rows with the space in-between the rows as the garden plots), the Inga trees are pruned at chest height. They have, at this stage, dominated the site and shaded out the terrible weeds. The branches are stripped of leaves and used as mulch, thus protecting the soil and preventing further weed growth. Larger branches are used as firewood, allowing families to obtain all the wood they need for cooking from the Inga plots and thereby tackling another important cause of deforestation. Crops are planted through the mulch within the pruned alleys. As it grows, the Inga  recovers and re-grows, providing not just an edible fruit crop (tasting like vanilla custard) and thousands of seeds in their pods,  the Inga leaves offer shade and protection from the sun. Once fully matured the crops are harvested. The Inga is then left to grow until the next planting season arrives, by which time they have fully recovered and the whole cycle is ready to be repeated, starting with pruning the Inga alleys once more. This system delivers huge benefits through ensuring a reliable harvest year after year from the same plot of land with minimal labor required. By recreating the conditions naturally found on the forest floor, Inga out-competes the aggressive invasive grasses which normally dominate the farmers’ plots. This biological weed control is hugely important as without it securing a harvest can require a huge amount of labor in terms of weeding. Often the combination of this takeover by weeds, as well as the loss of fertility, forces farmers to abandon their plots and clear new areas of rainforest. Families now have food security and cash crops from foods such as organic pineapple, turmeric, and pepper.

With Inga Alley Cropping:

  • Families have organically grown, sustainable food
  • Millions of tons of carbon will not be released into the atmosphere when  families are anchored to their land and not moving deeper into the rainforest to cut and burn new farming plots
  • Family farms sell cash crops
  • Rainforest habitats are protected as the family now has "Land for Life"
  • Wildlife habitats are protected and the rainforest is not destroyed
  • Soils are enriched by the nitrogen-fixing Inga trees
  • Soils are stabilized by the protection of the Inga foliage as the trees grow and enriched by the leaf mulch when the trees are pruned
  • Water sources are protected as the soil is stable and does not wash away
  • Erosion is controlled as soil does not wash into rivers/streams and reefs/ocean wildlife/and coral are protected

What actions do you propose to realize your stated goals?


By the introduction of the agroforestry system known as Inga Alley-cropping as the foundation of a low-input, debt-free and scientifically-proven model which is capable of yielding food-security in basic grains, together with a reliable income from cash-crops.The Guama Model results from over 25 years of research and development; the model is Inga Foundation’s response to the present and widespread problem of land degradation due to repeated slash-and- burn.

How introduced?

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 in the Cuero and Capapan river catchments The Cuero operation was established on Vanderbilt Family Foundation funds originally managed by the Honduran NGO Fundación Parque Nacional Pico Bonito (FUPNAPIB) with MRH as Overseas Coordinator. This operation is now directly funded by Inga Foundation and is implemented by its own employees.

Capapan and surrounding communities are located in a sub-catchment of the Rio Patuca; the major river system of the Mosquitia. The project forms part of a rural development strategy being implemented by Mosquitia Pawisa (MOPAWI); at a key location on the “FronteraAgricola” as it advances into the last wilderness of Central America.

Alley cropping plots for basic grains have been established in both areas. Expansion has been limited by lack of Inga seed and funds for both the Cuero and Capapan areas; both of which are seeing a high level of demand from smallholder families.

Scaling-up the present operation

This objective is for a major scaling-up of the introduction and adoption of Inga Alley-cropping in both these catchments and for the widespread adoption of the Guama Model (see below) to the level of about 200 families in each catchment.


The Guama Model

Taking the reported average holding of about 8 hectares per family as an example, the model might see the following possible land-use:The transformation of the present rotational 2-3 ha. annual slash-burning for (failing) subsistence farming to:

• 1 ha. Inga alley-cropping for food-security in basic grains

• 1 ha. Inga alley-cropping for cash-crops.

• 1 ha. of low-input fruit orchard (according to the family’s vision for itself).

• 5 ha. are thus liberated for tree-planting within a matrix of mixed Inga spp. as “nurse” trees for interplanting with broadleaf timber species of the primary forest. The Inga can be periodically lopped to provide firewood for the kitchen.

Scope and purpose…….cash-crops

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 chemical weed-control and provides the biological conditions for reliable cash-crop production. While yields might not match those of large-scale plantations, an acceptable crop can be produced on virtually no 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.This could mean organic pineapples, organic tomatoes where located reasonably close to road access; organic black pepper, vanilla, etc. where low-volume/high- value crops are more appropriate.

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 5-year phase of a 10-year overall plan. Alley-cropping for food security and the slow replacement of slash-and- burn takes priority within the first 5 years.

Who will take these actions?

This objective for bringing a major scaling-up of the introduction and adoption of Inga Alley-cropping is a region's best chance for the future. We would implement the massive scaling-up of Inga Alley Cropping  by finding agricultural advocates and  leaders in tropical regions and bring them to Honduras. This should be a combination of stakeholders (government farming agents,  land use & sustainability coordinators, but most importantly, some representative farmers  who are interested in learning a different way to farm).  The group will be embedded in the Honduras in the day-to-day details of our field operations with Inga staff for about a month. In that approximate time frame they have opportunities not just to view, but to be involved in all aspects of the operation of the farm. They will not just see the agroforestry system known as Inga Alley-cropping, they will have time with the 200 families and see the results of their labor. It is one thing to talk about a low-input, debt-free and scientifically-proven model of agriculture and quite another to be immersed in it and be able to see the yield-- food-security in basic grains, together with a reliable income from cash-crops--all accomplished with much less labor and no pesticides or herbicides.



Target geography

The Guama Model may serve for all tropical reasons

Inga tree Alley Cropping delivers a sustainable, resilient, rural livelihood that allows subsistence farming families an escape from poverty and an end to the practice of slash and burn. Guama is the local name for Inga trees and we refer to the 200 successful families in the Honduras as the Guama Model.

In Honduras, the average area of land (usually degraded and steeply sloping) available to a family for slash and burn agriculture is about 8 hectares. Normally, several hectares must be slashed and burned each year simply to meet the family’s basic food requirements. None of the 8 ha. can be used for anything other that slash and burn because all 8 ha. need to be used in rotation for burning at 2-3 year intervals in order to produce enough food to feed the family.

Furthermore, since nutrients are leached from the soil with every burn, the harvests obtained decline year after year, even with rotation of the plots burned. Ever declining yields draws families deeper and deeper into poverty, even as they work ever harder each year in order to make ends meet.

Inga alley cropping, in contrast, is highly efficient and 2 ha is more than enough to provide food security for the entire family, as well as firewood with which to cook. This therefore frees up, on average, 6 ha of land per family which the family can then choose to employed in other ways in order to help lift themselves out of poverty.

The Guama Model contains our estimate of maximum utility for a family to generate a secure and sustainable livelihood that will be resilient to threats from climate change or economic instability. It is important to stress, however, than none of our recommendations are compulsory and families are free to pick and choose what elements of the model they feel will best suit them.

The Guama Model: Creating Sustainable and Resilient Rural Livelihoods

Food security is the essential foundation for any sustainable low-input rural livelihood and 1-2 hectare of Inga Alley Cropping is enough to deliver this. Aside from these 1-2 ha of Inga alleys for food crops, the elements included in the Guama Model are:

 – Inga alleys for production of cash crops – a range of cash crops can be produced successfully and organically using Inga alley cropping, including pineapple, black pepper spice, vanilla, yams, plantain, chili, cardamon, etc.

 – Low maintenance fruit trees – We are currently supporting families to plant up to 2 ha of fruit tree crops. These can include an number of highly valuable cash crops such as cacao, rambutan, citrus, avocado etc. and help to diversify the farm, thereby making it more resilient to climate or economic shocks.

 – Reforestation – We are supporting the families who are willing to reforest as much of the the remaining land as possible, which could easily be up to 5 ha. Apart from the obvious environmental benefits of this, it also benefits families as in future they can sustainably harvest timber from this reforested area forest, providing them with another dependable source of income as well as materials for house construction. Many families have commented that they are keen to do it as it is one of the best ways they can leave a secure inheritance to their children, given that they often do not have access to banking services.


After the Amazon, the Congo Basin is the largest remaining expanse of tropical wilderness in the world. It is also one of the most threatened. We are currently in the process of setting up a new project working to combat slash and burn farming in the Chailllu Massif in Congo (Brazzavile).

As there are no Inga species native to the Congo, we have as our first priority a project  to identify a local species that can play the same role for us in the Congo Basin as Inga does in Central and South America. This is essential as, however good our intentions were, it would be highly irresponsible to introduce Inga as an exotic.We are collaborating with the African Legume Group of the Kew Botanic Gardens in our search for a Congolese ‘Inga’. Once identified, the hope is that the species will function across Central Africa, giving us the possibility of expanding our work across the region.

In the Congo we are currently working with MPD Congo, an iron-ore mining company, who is seeking to lessen the expected impact to the rainforest of potentially thousands of families moving into the area looking for work once their mining operation gets underway. Once we have identified an appropriate tree species, we will be able to work to support these families to develop secure and sustainable livelihoods using Alley Cropping and thereby protect the area’s rainforest from the damaging impact this huge influx of families could otherwise have.

The combined expertise of our Director Mike Hands, Dr. Martin Cheek of Kew and Congolese botanist Teva Kami enabled us to compile a list of 21 potential tree species. This has now been narrowed down to leave 9 very promising candidates.

MPD have now constructed a new tree nursery capable of holding several hundred thousand seedlings and are beginning trials to investigate how each of these shortlisted species will perform in an Alley Cropping system. We already have mulch trials in progress to test which of the candidate species are able to match Inga’s impressive weed-suppressing abilities. In addition, alleys using some of the candidate species have now been planted, with the rest of the species to be planted out in the near future. These trials will allow us to put each candidate species to the test in order to select the very best species for the job.

We have worked with a range of different organizations on a variety of projects. We have collaborated for many years with forest botanists at Kew Botanic Garden on a number of projects, such as establishing experimental Inga alley plots at San Juan in Costa Rica. We are collaborating on several fronts, with enquiries about the applicability of the Inga system coming in from many parts of the tropical world. Kew’s tropical legume specialists are actively seeking legume species that might function in other tropical forest regions as Inga does for us in the Central America. 

Our objective therefore is to identify as many indigenous candidate species as possible from regions throughout the tropics that could be used locally for alley cropping, as Inga is used in Central and South America, and to mount screening trials for these species. We are currently investigating setting up projects to work on this in a range of areas, including West Africa, Congo and Central Southern Africa, plus potentially a second project in Madagascar.


The Honduran NGO Mosquitia Pawisa (MOPAWI) has been a valued partner for many years.  Their mission is the conservation of the cultural and ecological heritage of one of Central America’s last wilderness areas, the Mosquitia.  They are running a rural development project in the communities around Capapan, Olancho, where they have a logistics base. Capapan is located in the upper watershed of the Patuca river and is close to the advancing front of logging and slash-and-burn agriculture. Inga Alley Cropping, including Inga alley cultivation of cacao as a cash crop, is one component of an integrated approach MOPAWI are using to try to slow the deforestation and protect the Mosquitia



In a particularly exciting development, EcoLogic are working to introduce Inga alley cropping to the Maya heartland.  Their former (now-ex) Regional Director, Sebastian Charchalac, first encountered the Inga alleys at our Demonstration Center in 2000.  In 2007, they began establishing alleys with two Maya communities in Tikal and Sarstoon.  Our Extension Officer, Faustino Reyes, was “borrowed” in late 2010 to demonstrate pruning of the Inga alleys and helped to plant maize within the pruned alleys. They have also established control plots growing maize conventionally next to the Inga alley plots, in order to demonstrate the different results of the two methods. Very low yields were produced by the control plots, while the Inga plots gave a high yield and achieved this without any weeding. This clear demonstration of the benefits of Inga has helped to convince the local people and EcoLogic reports that the communities are now converted “Guameros locos” and are eager to plant more Inga alleys.

What do you expect are the costs associated with piloting and implementing the solution, and what is your business model?

Costs of replication

Present experience indicates that the effective establishment of secure demo-farms/seedbanks/nurseries, together with the staff and capital outlays for a budget of approximately $150-200,000 in the first year. Wider dissemination of the model will be achieved by adopting the same approach that is currently yielding success in the Honduras. Present policy is to concentrate resources in those areas where we are already working and are well-known, with approximately 200 families. Our task is to get the alley cropping system convincingly established in two target river catchments, and to use their success as the springboard for wider dissemination of the model. The Inga system is revolutionary in the eyes of the subsistence farming families at whom it is aimed, because it is not a "quick fix" to the serious problems confronting them.


The success of Inga Alley Cropping is due to the families who participate. The Inga system has ALWAYS been a bottom-up process. As our numbers have grown, there has emerged a self-perpetuating momentum in the Honduras. Because this is a new system, it is necessary to provide one-on-one support and encouragement for 2-3 years.  As the model becomes more familiar, the system will spread easier.

This is demanding on the time and resources of our field extension workers. We expect that, once a "critical mass" of families begin clearly demonstrating to their neighbors the food-security and cash benefits of the system  further spread of the system will happen faster. The system contains the seeds of its own replication (literally and figuratively).

There is no short-cut to the self-perpetuating momentum that is our ultimate goal. Our 200 families serve as a model of sustainable good practice and we anticipate a doubling of the number in another year.

Crucial to a rapid scaling-up of Inga Alley Cropping is the education piece for running open courses for groups of visiting government and non-government agencies, farmer groups, etc. from all over the Cent. Amer. region. We need exposure and advocates who are in a position to consider this system. We would like to see short courses  (4-5 day classes) which would be held at our demo centers in the Honduras as an introduction and to plan working groups who would return with others who want to learn and then implement the system. Critical is  meeting and visiting the families who have adopted and are successfully implementing, the Guama Model. A teaching facility at our Centre in Las Flores will be needed in support of this; in addition to those facilities available to us in the Univ. (UNAH/CURLA) at La Ceiba. These courses were proposed in '15, but were not funded

In short, we have successful pilot programs in place. With exposure and advocates we will offer the system to other regions and continue to scale up.



Related solutions


The link below to PBS is a summary of the Inga documentary from Adam Wakeling --entitled "Up in Smoke"


The Cambridge Research Projects (1986-2002)

Inga Foundation projects are based upon the findings of long-term studies run by Inga’s founder Mike Hands for Cambridge University into subsistence slash-and-burn farming.  Research was conducted in secondary rainforest, on two acid-soil sites, in the humid tropical lowlands of Costa Rica in the late 80s and early 90s and focused on the ecology of both intact rainforest and slash-and-burn systems on acid soils.

This research was particularly important because of the confusions and contradictions which dominated the scientific literature at the time, especially regarding the fluxes and fates of plant nutrients during and after burning.

 The overall objectives were, firstly, to determine the key ecological constraints causing slash-and-burn to fail, and secondly, to establish the minimal ecological requirements of an alternative sustainable system.


Uses of Inga for Alley Cropping and Soil Regeneration; Inga Utilization (Chapter 5) by Mike Hands.
Download PDF

Phosphorus Dynamics In Slash-and-Burn; Phosphorus in the Global Environment (Chapter 10) by Mike Hands et al.   Download PDF

Research Findings

In total, a series of four research and development projects in Costa Rica and later in Honduras, yielded vital and powerful insights into why slash-and-burn works in the short term but then fails so quickly, and why and how the soil of slash-and-burn sites degrades. The findings are held to be applicable to a wide range of soil types across much of Latin America.

From over the 6 years of trials one system capable of sustaining a harvest was discovered- the agroforestry technique known as alley cropping, but using the indigenous nitrogen-fixing trees of the genus Inga rather than conventional alley-cropping species.

The studies demonstrated that phosphorus (P) is the key limiting nutrient in slash and burn systems. Inga alley cropping works sustainably because it retains and recycles the phosphorus that it inherits from the original burned forest ecosystem. In addition to this, it also retrieves, retains and recycles the small supplementary quantities of rock-phosphate that are all that the subsistence farmer can afford to apply. This rock-phosphate replaces the phosphorus lost with each crop harvest.

It is important to stress that this system of Inga Alley Cropping is radically different to the original notion of alley cropping developed in West Africa that is now widely regarded as a failed hope of the 1980s.

The Inga system provides soil protection, weed control and a nutrient regime that is far superior to those provided by the conventional alley cropping species (eg Leucaena spp; Gliricidia sp; Calliandra spp; etc.) used in the other systems.

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Inga Alley Cropping Saves Rainforests/Sustains families/Sequesters carbon
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