Hope for progress on slash-and-burn farming
Slash-and-burn subsistence agriculture has fed millions of families over past centuries; today it maintains their descendants 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 around 1 billion tonnes of carbon annually to the atmosphere; more than half of all global transport combined. Neither this process, nor the families’ attempts to feed themselves, is sustainable today.
About 25 years ago I began working on a new system of agroforestry which depends upon the soil-restorative qualities of fast-growing, nitrogen-fixing trees from the Amazon basin. The system has emerged from many years’ research, development and trial which was begun in the mid 1980′s by me and my colleagues in the University of Cambridge, the Royal Botanic Gardens, Kew, and others in the region. Together we founded an organization called The Inga Foundation to extend and promote the ground-breaking discoveries of those R&D phases.
Inga Alley-cropping is a system of mulching using pruned green leaves from the trees which are contour-planted in hedgerows; it has proved itself capable of achieving food-security in basic-grains for the family, upon one permanent plot near their dwelling. It produces firewood for the kitchen; it virtually eliminates the need for weed-control. Additional plots enable the whole family to be involved in their own cash-crop economy; located, for the first time, on their own doorstep.
Food security in basic grains is the indispensible pre-condition for a complete and sustainable rural livelihood. Many cash-crop cultivars have been trialled successfully in the Inga Alley system. Once the inexorable and debilitating pressure of slash-and-burn has been removed from the equation, degraded land, which would have been slash/burned every second or third year, can now be restored to permanent tree-cover. Some combination of fruit and timber trees is likely to be the family’s choice.
The system is by no means a “quick fix” to such a deep-rooted problem; it requires effort from the family and their patience while the developing Inga trees gain dominance over the weed-infested site. The process can take over two years. Once it achieves site-recapture, the system requires minimal inputs of soil supplements or labor to maintain it.
We now have many case histories of farmers taking their first maize crops for many years from plots declared by them to have been “sterile” before recapture by the Inga trees.
Still, despite these successful outcomes of this approach, convincing farmers who have relied on slash and burn for generations, and whose very survival depends on the process, is no easy feat. Transitioning to a new way of farming requires not only the gain of their trust that the new method will indeed work, but it also requires an infusion of money that these farmers do not have. So we turn to governments and NGOs for the economic support that will be needed to make Inga-Alley cropping the norm. We’ve achieved some success in this area, but the fight continues.
You can see the challenges—and successes—we’ve faced in bringing Inga Alley-cropping to farmers in Honduras in Up in Smoke, a new documentary that was shot over the past four years by a filmmaker named Adam Wakeling. It was recently selected for inclusion in The Economist Film Project, which will present a clip of the film tonight on PBS NewsHour.
Hopefully, as more people become aware of the promise that exists in bringing an end to slash and burn agriculture, and the urgency with which we must make this transition, the more support we will receive from the agencies who have the power and means to invest in a more sustainable future.
Mike Hands is a tropical ecologist specializing in the ecology of Tropical Rain Forest, and especially in the ecology of slash-and-burn subsistence agriculture. Hands began the studies that have led to the making of Up In Smoke in the mid 1980′s. He worked for 14 years as Senior Research Associate in the University of Cambridge; working almost entirely in Central America. Hands directed a series of four research projects in Costa Rica and Honduras. He is currently the secretary and Founder-Trustee of Inga Foundation which has been established to continue and expand this pioneering work in the world’s rain forests. He is a lifelong naturalist.