Factors affecting soil arylsulfatase activity.

A study of the effects of various soil pretreatments on soil arylsulfatase activity showed that storage at — 10C is a satisfactory method of preserving field-moist soil samples for assay of arylsulfatase activity. Storage of field-moist soils at 5C or 22-24C for 3 months led to a decrease in arylsulfatase activity (average, 8% at 5C, 18% at 22-24C), but storage at — 10C for the same period did not significantly affect this activity. Air-drying of field-moist soils at 22-24C caused a marked increase in arylsulfatase activity (average, 43% ), and ovendrying (105C) caused a marked decrease (average, 54%). A slow decrease in arylsulfatase activity was observed when air-dried soils were stored at 22-24C. Arylsulfatase activity decreased markedly with depth in six soil profiles examined. This decrease was associated with a decrease in organic matter content, and studies with surface soils differing markedly in physical and chemical properties showed that soil arylsulfatase activity was significantly correlated with soil organic matter content. Soil arylsulfatases were not deactivated by most of the reagents used to study the sulfur status of soils. Additional