Interactions of Soil Order and Land Use Management on Soil Properties in the Kukart Watershed, Kyrgyzstan

Table 2

Conditions for assay of soil enzyme activities and their role in soil biogeochemical functioning.

Class/EC number	Recommended name	Role in soil function		Assay conditions
			Reaction	Substrate	Optimum pH
C cycling
3.2.1.21	𝛽-Glucosidase	Cellulose degradation, produces glucose needed by plants and microorganisms	Glucoside-R + H2O→Glucose + R–OH	p-Nitrophenyl-𝛽-D-glucopyranoside (10 mM)	6
C and N cycling
3.2.1.30	𝛽-Glucosaminidase	Chitin degradation, produces amino sugars, one of the major sources of mineralizable N	R-N-acetyl-𝛽-D glucosaminide→R–OH + N-acetyl-𝛽-D-glucosaminide	p-Nitrophenyl-N-acetyl-𝛽-D-glucosaminide (10 mM)	5.5
P cycling
3.1.3.2	Acid Phosphatase	Produces plant available phosphates, predominant in acid soils	RNa2PO4 + H2O→ R–OH + Na2HPO4	p-Nitrophenyl-phosphate (10 mM)	6.5
3.1.3.1	Alkaline Phosphatase	Produces plant available phosphates, predominant in alkaline soils	RNa2PO4 + H2O→ R–OH + Na2HPO4	p-Nitrophenyl-phosphate (10 mM)	6.5
3.1.4.1	Phosphodiesterase	Produced from plants, animals, and microorganisms	RNa2 2PO4 + H2O→ RNa2PO4 + R–OH	bis-p-nitrophenyl phosphate (10 mM)	8
S cycling
3.1.6.1	Arylsulfatase	Produces plant available sulfates	Phenol sulfate + H2O→ phenol + sulfate	p-Nitrophenyl-sulfate (10 mM)	5.8