Soil and land degradation in the tropics can be identified and described interms of physical, chemical, and biological changes from its pristine state brought about by naturaland anthropogenic influences. A characteri...Soil and land degradation in the tropics can be identified and described interms of physical, chemical, and biological changes from its pristine state brought about by naturaland anthropogenic influences. A characteristic of these ecosystems is their capacity to recyclenutrients through soil organic matter (SOM). Following disturbance through changed land management,SOM is rapidly mineralized and there is a corresponding decline in fertility and the variable chargecomponent of the cation exchange capacity. As these ecosystems are strongly dependent on SOM fortheir functionality, changed land use can have irreversible impacts on the productivity of thesesystems. The paper focuses on quantifying chemical degradation through 'benchmarking' using datafrom paired sites in tropical China and Thailand using surface charge fingerprinting. Using valuestaken from the fingerprint of an undisturbed soil, an index of chemical degradation from 'ideality'was calculated. Various management strategies that attempt to reverse degradative trends or improvepoor quality soils in their natural condition are discussed, such as the addition of natural claysand silicated materials. Results are present to show the effect of each of the aforementionedstrategies on surface charge characteristics and associated increases in plant productivity.展开更多
基金Project financially supported by the Australian Centre for International Agricultural Research(ACIAR) and the Sugar Research and Development Corporation(SRDC),Australia.
文摘Soil and land degradation in the tropics can be identified and described interms of physical, chemical, and biological changes from its pristine state brought about by naturaland anthropogenic influences. A characteristic of these ecosystems is their capacity to recyclenutrients through soil organic matter (SOM). Following disturbance through changed land management,SOM is rapidly mineralized and there is a corresponding decline in fertility and the variable chargecomponent of the cation exchange capacity. As these ecosystems are strongly dependent on SOM fortheir functionality, changed land use can have irreversible impacts on the productivity of thesesystems. The paper focuses on quantifying chemical degradation through 'benchmarking' using datafrom paired sites in tropical China and Thailand using surface charge fingerprinting. Using valuestaken from the fingerprint of an undisturbed soil, an index of chemical degradation from 'ideality'was calculated. Various management strategies that attempt to reverse degradative trends or improvepoor quality soils in their natural condition are discussed, such as the addition of natural claysand silicated materials. Results are present to show the effect of each of the aforementionedstrategies on surface charge characteristics and associated increases in plant productivity.
