EPR,NMR AND DRIFT SPECTROSCOPY DATA,ANALYZED BY CHEMOMETRIC METHODS,FOR CONSIDERATIONS OF CHEMICAL STRUCTURES OF HUMIC SUBSTANCES FROM SOILS IN DIFFERENT MANAGEMENT SYSTEMS

摘要

The search for chemical structures for humic substances(HS)by soil and water scientists has for long been ongoing.Researchers have had considerable success in assigning functionality,but as yet no reliable structural concepts have emerged.This can be attributed to the complex mixtures in the associations of molecules that compose HS.Thus it has not been possible to establish a relationship between chemical structural aspects of HS and soil management methods.