ISOLATION OF HUMUS WITH ENZYMATIC ACTIVITY FROM SOIL

Abstract

Some observations are reported on soil extracts obtained by two methods of extracting soil organic matter. These methods yield products having urease activity that may be regarded as native humus. A somewhat lower urease activity is extracted than is commensurate with the carbon extracted but matches the nitrogen extracted in a summation of the contents of four major extracts, but such is not the case among the individual extracts. Further, following high-speed centrifugation it was found that sedimentation of urease activity is greater than that of the organic matter; hence the urease is not uniformly associated with the organic matter.