The Genus Inga contains about 300 species in tropical America. They are thought to have evolved into so many species during the last 2 million years only. Artefacts in the shape of Inga seeds pods have been found in Peru and elsewhere dating back thousands of years. 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 also been used as a shade tree for coffee, cacao and tea.

There are 10 main reasons why Inga were chosen by Mike Hands as the shade trees for successful alley-cropping:

Transforming rural livelihoods in place of slash and burn

Empirical evidence has accumulated over the life of the Cambridge Inga Projects, and continues to accumulate in the succeeding projects, that the alley-cropping techniques described here carry the potential for a fundamental transformation in the livelihoods of subsistence farmers and their families.  These transformations are much more fundamental than those implicit in the Green Revolution (GR) technologies of the 1960s and '70s.  Moreover, and more importantly, the technologies described here are characterised by the complete absence of external debt in their implementation. 

Present funding channels

Major tranches of funding for the FUPNAPIB, MOPAWI and Chanchamayo Projects  are channeled directly from the funding trusts to the implementing NGOs.  Smaller programs are funded from private donations that have accrued since the publication of journal and newspaper articles about the Cambridge Projects.  These have been channeled through funds managed by the Charities Aid Foundation (CAF) who have vetted the recipients.