Enzyme activities in Appalachian soils: 4. Dehydrogenase

Abstract

Dehydrogenase enzymes significantly mediate biological oxidation of organic compounds in soil. Dehydrogenase activities were determined in surface and subsurface horizons of 14 major hill land soils of the Appalachian Region. Soil samples were stored air‐dry (AD) and field‐moist at 4°C prior to determination of dehydrogenase activities. Each soil type had its own level of dehydrogenase activity. The average dehydrogenase activities of surface and subsurface horizons stored at 4°C were 1.4 and 3.3 times higher than soil samples stored AD. Mean dehydrogenase activities of surface horizons were 5.3 and 2.2 times higher than subsurface horizons stored at AD and 4°C, respectively. Depending on storage method (AD or 4°C) and type of horizon (surface or subsurface). dehydrogenase activities were either positively or negatively related to soil moisture status, organic C, total N, soil texture, and forms of ? and S. Most of these relationships were nonsignificant. Dehydrogenase activities were positively related to exchangeable bases. CEC, and ratio of Mg/Mg+Ca; however. the relationships were mostly significant in surface horizons.