Redox potential as a soil health indicator -- how does it compare to
existing methods?
Abstract
Soil health is the capability of soil to provide ecosystem services.
These can be quantified through multiple separate indicators
(N-mineralization, water infiltration, aggregate stability, etc.) or by
a single proxy that integrates many soil processes. Two commonly used
integrative measurements are the soil 24h-respiration test (CO2burst)
and the visual evaluation of soil structure (VESS). Both are fast, but
capture only a part of whole phenomenon of soil health. Soil redox
potential is a promising soil and plant health indicator. The redox
potential is controlled by soil chemical oxidation-reduction reactions
and therefore integrates several processes. However, this method has
been tested only on a few soils. In this study, we evaluated redox by
comparing it with other established soil health indicators on 35 fields
in Finland. Based on the results, redox correlated well with soil
biological activity, structure, and texture. Soils with good structure
had an oxidized redox status. A low redox state was connected to high
biological activity. The carbon farming practices resulted in lower
oxidation. A combination of redox and pH could be used to classify
soils. The analysis supports the use of redox as a soil health
indicator, but further research is needed in identifying the processes
and properties the redox is an indicator for.