Enzyme activities (Soil enzymes)

Soil Health

Biological

Summary

Enzymes are integral to various metabolic processes of the soil, like decomposition of organic materials, impacting carbon sequestration, nutrient availability, soil productivity, and the global carbon cycle. As early and sensitive indicators of soil health changes, they are responsive to shifts in soil use and management, pollution and climate, and they represent the metabolic status of the soil microbial community (Cardoso et al., 2013; Stott et al., 2019). They therefore serve as indicators for microbial activity, soil productivity, and the impact of pollutants. Changes in soil microbial activity, reflected in metabolic enzyme levels, can estimate ecosystem disturbance (Neiendam Nielsen & Winding, 2002; Cardoso et al., 2013; Stott et al., 2019).

Methodology summary

The three most common enzymes for use are:

N-acetyl-β-D-glucosaminidase (NAG) that is involved in both the C- and N-Cycle
Phosphomonoesterases (acid/alkaline phosphatase; Pase) is involved in the P-cycle
Arylsulfatase (AS) that is involved in the S-cycle

(Stott et al., 2019) See appendix 4 of Stott, D. E. (2019), Recommended Soil Health Indicators and Associated Laboratory Procedures, for detailed procedure.

Metric threshold or direction of change

It is generally agreed in the literature that higher EAs are present in healthier soils, as they are necessary for improved nutrient cycling in the soil (thus following the more-is-better model) (Stott et al., 2019).

Agricultural
Forest
Grassland
Peatland
Saltmarsh
Wetland

Scale

Community

Cost

High

Tier

Future

Technical expertise

High