Water Extractable Fraction of Soil Organic Carbon as an Indicator of Soil Quality:A Literature Review

Abstract

Total soil organic matter (SOM) content is a key attribute of soil quality (SQ) since it has far-reaching effects on soil physical, chemical, and biological properties. However, changes in contents of soil organic carbon occur only slowly and do not provide an adequate indication of important short-term changes in SQ. The declining SQ is often potentially the most serious both in the context of farm production and environmental damage. Water extractable organic carbon (WEOC) in the soil represents only a tiny portion of SOM. However, WEOC involves in key soil processes which are either directly or indirectly linked with soil quality. This pool acts as a substrate for microbial activity, a primary source of mineralizable N, S, and P. This review focuses on the importance of WEOC as a sensitive indicator of changing soil quality.