Describes the processes which maintain the integrity of natural ecosystems and the mechanisms buffering the potential effects of climate extremes and other perturbations on soil and nutrient losses. The Tropical Soil Biology and Fertility Programme reference sites represent a wide range of systems which are persistent under very different climates. The derived cropping systems are also sustainable provided that certain key ecological properties are maintained. These include a basic complement of plant life forms, persistent rooting systems in high rainfall zones, maintenance of litter and soil organic matter pools, and long-term balance of nutrient gains and losses. Traditional (low external input) farming systems, which usually involve a high diversity of plant species, often include management practices based on the intuitive understanding farmers have developed around these principles. Intensification of these systems, and long rotation (tree) crops have frequently resulted in declining yields as a consequence of one or more component parameters of the system becoming uncoupled or falling below optimal levels to maintain soil properties and proceses. In order to develop more sustainable cropping systems, optimising the use of scarce internal and external resources, the critical levels of soil properties and ways of managing soil processes need to be determined
Ano de publicação
1994
Autores
Brown S; Woomer P L; Anderson J M; Barrios E
Idioma
English
Palavras-chave
soil fertility, site classes, ecological factors, environment
