Farmers in Honduras and Costa Rica are being taught an agrofestry technique, known as Inga Alley Cropping, which provides farmers with a viable, sustainable alternative to slash-and-burn farming.
The inga is a fast-growing tree with roots that fix nitrogen, so it replenishes the soil. In alley cropping, farmers plant inga trees in rows. Their shade kills weeds and creates space for planting maize or beans. Then the trees are pruned back so sunlight can reach the crops until harvest.
This system delivers huge benefits through ensuring a reliable harvest year after year from the same plot of land with minimal labour required. By recreating the conditions naturally found on the forest floor, Inga out-competes the aggressive invasive grasses which normally dominate the farmers’ plots.
The ingas’ roots keep the soil rich, so the farmer does not need to slash and burn more land, meaning less carbon pollution.
Inga Alley Cropping is the revolutionary alternative to slash and burn developed by Inga Foundation’s Director, Mike Hands, based on the insights gained through over a decade of research into slash and burn in partnership with Cambridge University.
Slash-and-burn is a subsistence farming method used by millions of families in the tropics in which families cut down and burn an 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.
Of the different potential alternatives to slash-and-burn investigated by Mike Hands, the only truly sustainable system to emerge from years of scientific research was alley cropping using nitrogen-fixing tree species from the genus Inga.
The Genus Inga contains around 300 species in tropical America, which are thought to have all evolved within just the last 2 million years. Artifacts in the shape of Inga seeds pods have been found in Peru and elsewhere dating back thousands of years and the tree is an important part of the local agro-economy. The fruit of many are edible and part of the basic diet of the indigenous pre-Columbian inhabitants of Peru. The tree has been used as a shade tree for coffee, cacao and tea in the past.
Inga Alley Cropping is capable of maintaining soil fertility and good harvests year after year, thereby breaking the cycle of slash and burn and allowing families to gain long term food security on one piece of land.
In addition to Central America and South America, the Inga Foundation is also working in the Congo. In the search for a Congolese “Inga”, the Inga Foundation have teamed up with the African Legume Group of the Kew Botanic Gardens and Congolese botanist Teva Kami. To date, the team have compiled a list of 21 potential tree species, of which has now been narrowed down to nine with trials are underway.
Once identified, the hope is that the species will function across Central Africa, working to combat slash and burn farming across the region.
Rosa Medea is Life & Soul Magazine’s Chief. She writes about lifestyle including sustainable and green living.