Soil health: Critical evaluation and approaches

Soil Health is defined as the capacity of a soil to function within ecosystem and land-use boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health (FAO, 2015). This soil functionality is mainly defined by processes and fluxes – the dynamic parameters, and not on their total amounts. Most studies, however, use pools of nutrients or static properties, which are hardly to connect with functions.

The main aims of this presentation is to raise the difference between commonly used pools (not reflecting the soil health) and fluxes – defining the soil health, but measured very seldom. Further, the question of the scale size by evaluation of soil health will be discussed.

Numerous soil quality indices (SQI) have been suggested to evaluate specific groups of soil functions, but the comparison of such SQI is impossible because they are based on a combination of properties specific for each soil. To avoid this problem, we suggest an SQI-area approach based on comparison of the areas on a radar diagram of a combination of chemical, biological and physical properties. The new approach is independent of the SQI principle and allows simple comparison of parameter groups and soils of various degradation or recovery stages.

Another approach analyzing the resistance and sensitivity of properties to degradation is suggested to evaluate soil health. The resistance and sensitivity of soil properties are determined through comparison with the decrease of soil organic carbon (SOC) as a universal parameter responsible for many functions. The SQI-area and resistance/sensitivity approaches were tested based on the degradation of Alisols and on recovery of Phaeozems and Chernozems chronosequences after the abandonment of cropland soils. Both the SQI-area and the resistance/sensitivity approaches provide very good visualistion of the results, are useful for basic and applied research, and help decisionmakers to evaluate land-use practices and measure the degree of soil degradation.

References
Guillaume T, Maranguit D, Murtilaksono K, Kuzyakov Y. 2016. Sensitivity and resistance of soil fertility indicators to land-use changes: New concept and examples from conversion of Indonesian rainforest to plantations. Ecological Indicators 67, 49-57.
Kuzyakov Y, Gunina A, Zamanian K, Tian J, Luo Y, Xu X, Yudina A, Aponte H, Alharbi H, Ovsepyan L, Kurganova L, Ge T, Guillaume T. 2020. New approaches for evaluation of soil health, sensitivity and resistance to degradation. Frontiers of Agricultural Science and Engineering 7 (3), 282-288.