Amazon basin soils: management for continuous crop production.

Technology has been developed which permits continuous production of annual crops in some of the acid, infertile soils of the Amazon Basin. Studies in Yurimaguas, Peru, show that three grain crops can be produced annually with appropriate fertilizer inputs. Twenty-one crops have been harvested during the past 8(1/2) years in the same field, with an average annual production of 7.8 tons of grain per hectare. Soil properties are improving with continuous cultivation. The technology has been validated by local farmers, who normally practice shifting cultivation. Economic interpretations indicate large increases in annual family farm income and a high return on the investment of chemical inputs. Other promising land use alternatives include low-input crop production systems, paddy rice production in fertile alluvial soils, and pastures or agroforestry in rolling areas. Stable, continuous food crop production is an attractive alternative to shifting cultivation in humid tropical regions experiencing severe demographic pressures. For each hectare of land managed in a highly productive manner, there may be less need for clearing additional tropical forests to meet food demands.