Soil and land degradation in the tropics can be identified and described in terms of physical,chemical,and biological changes from its pristine state brought about by natural and anthropogenic influences.A characteris...Soil and land degradation in the tropics can be identified and described in terms of physical,chemical,and biological changes from its pristine state brought about by natural and anthropogenic influences.A characteristic of these ecosystems is their capacity to recycle nutrients through soil organic matter(SOM). Following disturbance through changed land management.SOM is rapidly mineralized and there is a cor responding decline in fertility and the variable charge component of the cation exchange capacity.As these ecosystems are strongly dependent on SOM for their functionality,changed land use can have irreversible impacts on the productivity of these systems.The paper focuses on quantifying chemical degradation throughbenchmaking using data from paried sites in tropical China and Thailand using surface charge finger printing.Using values taken from the fingerprint of an undistubed soil,an index of chemical degradation from ideality was calculated.Various management stratgeies that attempt to reverse degradative trends or improve poor quality soils in their natural condition are discussed.such as the ddition of natural clays and silicated materials.Results are present to whow the effect of each of the aforementional strategies 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 in terms of physical,chemical,and biological changes from its pristine state brought about by natural and anthropogenic influences.A characteristic of these ecosystems is their capacity to recycle nutrients through soil organic matter(SOM). Following disturbance through changed land management.SOM is rapidly mineralized and there is a cor responding decline in fertility and the variable charge component of the cation exchange capacity.As these ecosystems are strongly dependent on SOM for their functionality,changed land use can have irreversible impacts on the productivity of these systems.The paper focuses on quantifying chemical degradation throughbenchmaking using data from paried sites in tropical China and Thailand using surface charge finger printing.Using values taken from the fingerprint of an undistubed soil,an index of chemical degradation from ideality was calculated.Various management stratgeies that attempt to reverse degradative trends or improve poor quality soils in their natural condition are discussed.such as the ddition of natural clays and silicated materials.Results are present to whow the effect of each of the aforementional strategies on surface charge characteristics and associated increases in plant productivity.
