TRADITIONAL FALLOW SYSTEMS OF THE AMERICA

Six neotropical traditional fallow systems are described: 1) enriched fallows of the Amazon, 2) Babassu palm (Orbignya phalerata Mart.) fore sts of central and northern Brazil, 3) bracatinga (Mimosa scabrella Be nth) improved fallow of southeastern Brazil, 4) carbon negro (Mimosa t enuiflora Willd.) fallow of the wet-dry zone of Mesoamerica, 5) frijol illo (Senna guatemalensis Donn. Smith) of high-elevation zones in sout hern Honduras, and 6) caragra (Lippia torresii) fallow of humid zones of Costa Rica. These systems include both biologically and economicall y enriched fallows. Some (e.g., the enriched fallows of the Amazon) re quire a considerable degree of human intervention, while others (e.g., the bracatinga and carbon negro fallows) seem to form with little hum an encouragement, following the bum in shifting cultivation systems. S ome of the systems (e.g., frijolillo and caragra) are quite site-speci fic and have a limited distribution; others (e.g., babassu, bracatinga , and carbon negro) occur over large areas and could be adapted to con siderable areas in the Americas. As economic analyses are generally la cking, it is unclear what benefits would be achieved from a wider use of these systems. Most of the biologically enriched fallows seem able to maintain low yields of food crops at low input levels. Some of the economically enriched fallows seem able to produce higher economic ret urns.