Low-Input Technology for Managing Oxisols and Ultisols in Tropical America

Abstract

Publisher Summary The purpose of this chapter is to bring together examples of low-input soil management technology adapted to well-drained, acid, inherently infertile soils of the American tropics classified mainly as Oxisols and Ultisols. Soil taxonomy terminology, including soil moisture regimes, is used. The outcome of the race between world food production and population is determined in the tropics, where most of the world's undernourished people live. The applicability of high-input soil management technologies, however, diminishes in marginal lands where soil and water constraints are not easily overcome at low cost. The rising price spiral of petroleum-related products since has limited the economic feasibility of soil management technologies based on the intensive use of purchased inputs, particularly for farmers with limited resources in the tropics. The term ‘‘low’’ is used in relation to “high”-input technology where the application of fertilizers and amendments largely eliminate chemical soil constraints. The identification of plant species and ecotypes tolerant to the main acid soil stresses allows the development of low-input soil management systems for Oxisol and Ultisol regions where socioeconomic constraints prevent the widespread application of large quantities of lime and fertilizers. The basic approach is to use plants adapted to acid soil constraints, to maximize the use of fertilizers and lime needed to produce about 80% of their maximum yield, and to take advantage of favorable attributes of acid, infertile Oxisols and Ultisols.