Shifting Cultivation and Tropical Soils: Patterns, Problems, and Possible Improvements

FAO (1957) has labeled shifting cultivation as the most serious land..use problem in the tropical world. Shifting cultivation has been condemned as destructive and frequently has been seen as the work of ignorant people, thoughtlessly slashing and burning, wasting valuable forest and soil resources, and increasing the danger of runoff and erosion (Grandstaff 1981). Far from ending or even diminishing, shifting cultivation has increased in the twenty.. five years since the alarm was sounded. It is estimated that there are over 250 million shifting cultivators worldwide, 100 million in Southeast Asia alone (Hatch and Tie 1979). In fact, shifting cultivation is an ideal solution for agriculture in the humid tropics (Watters 1971), as long as the human population density is not too high and fallow periods are long enough to restore soil fertility. This agricultural system is ecologically sound and meets a variety of human needs with great efficiency, particularly with regard to labor and other agricultural inputs. However, in many areas where shifting cultivation has been practiced successfully for centuries, the population is growing rapidly, largely due to migration from other areas. People also are opening up new areas that have not been subjected to agriculture before and where shifting cultivation may not be appropriate. As a consequence, many of the destructive effects of shifting cultivation, though sometimes more imagined than real, are increasingly becoming a reality. Unfortunately, no alternative food production systems have yet proven biologically and economically workable for many areas of the tropics (Eckholm 1976). This chapter reviews effects of shifting cultivation on soils and suggests alternatives that might be useful for dealing with contemporary problems. The chapter draws on a worldwide literature but applies fully to shifting cultivation in Southeast Asia. Soil classification follows the FAOjUNESC