Annual Variation in Soil Enzyme Activity in a Paddy Field: Soil Temperature and Nutrient Availability Are Important for Controlling Enzyme Activities

Figure 2

Annual variations in enzyme activities involved in C, N, P, and S cycling (a) and the ratios of N-, P-, and S-acquiring enzymes to β-D-glucosidase activity (b). (a) Filled triangle, arylsulfatase (µmol p-nitrophenol g⁻¹·h⁻¹); open circle, L-asparaginase (µmol NH₄⁺-N g⁻¹·h⁻¹); filled circle, acid phosphatase (µmol p-nitrophenol g⁻¹·h⁻¹); open triangle, β-D-glucosidase (µmol p-nitrophenol g⁻¹·h⁻¹). (b) Open circle, ratio of L-asparaginase to β-D-glucosidase activity; filled triangle, ratio of arylsulfatase to β-D-glucosidase activity; filled circle, ratio of acid phosphatase to β-D-glucosidase activity. Data points represent means, and the error bars represent standard deviations.

(a)

(b)