When human populations were tiny and the forests seemingly limitless slash and burn may have been a sustainable form of agriculture, but that era is long since passed: now we need something better. Feeding 7 plus billion of us, lowering atmospheric Co2 and overcoming poverty requires humanity to find better ways to manage fragile tropical forest ecosystems.
One of the best practices has been pioneered by British tropical agronomist Mike Hands and the organisation he founded, The Inga Foundation. He has worked with communities in Central America who practiced slash and burn or swidden agriculture. They were forced to move-on every few years into new areas of forest, but as populations have grown the long periods of fallow are no longer possible and the forest cannot properly regenerate. This is particularly a problem with the poor acidic soils so common in rainforest areas.
The Inga is a family of trees with about 300 species occurring in the tropical Americas, each suited to particular soils and altitudes. Most of these species of Inga germinate quickly, grow rapidly and are tolerant of the poor acidic soils of the region. They fix nitrogen, host mycorrhizal fungi and so aid soil fertility, and their leaves make a wonderful water and soil conserving mulch. They are perfect for alley cropping with maize and beans, provide good shade to valuable cash crops such as coffee, cacao, pepper and vanilla and can be used as a nurse crop to establish mahogany and the inga themselves provide valuable edible fruits and fuelwood.
With the increased fertility afforded by Inga alley cropping, maize, beans and other crops can be grown and rotated year after year on the same land, taking the pressure off the remaining forests and allowing communities to settle permanently, grow more valuable perennial cash crops, increase their incomes and send their children to school.
When I first read about all this in an article in The Ecologist Magazine in 2005 I was really impressed. I’ve cited this as an example of really good land use in numerous talks. Now it is very good to hear that Mike Hands and the Inga Foundation have received a grant of $3 million to fund a 10 year programme to develop this work in the Rio Cuero area of Honduras.
See more here http://www.ingafoundation.org/