Soil quality: an indicator of sustainable land management?

Soil quality appears to be an ideal indicator of sustainable land management. Soil is the foundation for nearly all land uses. Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. By reflecting the basic capacity of the soil to function, it integrates across many potential uses. Nonetheless, few land managers have adopted soil quality as an indicator of sustainable land management. There are a number of constraints to adoption. Most could be overcome through a concerted effort by the research community. Specifically, we need to address the following issues: (1) demonstrate causal relationships between soil quality and ecosystem functions, including biodiversity conservation, biomass production and conservation of soil and water resources. True calibration of soil quality requires more than merely comparing values across management systems; (2) increase the power of soil quality indicators to predict response to disturbance. Although there are many indicators that reflect the current capacity of a soil to function, there are few that can predict the capacity of the soil to continue to function under a range of disturbance regimes. Both resistance and resilience need to be considered; (3) Increase accessibility of monitoring systems to land managers. Many existing systems are too complex, too expensive, or both; (4) Integrate soil quality with other biophysical and socio-economic indicators. Effective early-warning monitoring systems will require not just the inclusion of both biophysical and socio-economic indicators, but also the development of models that incorporate feedbacks between soil quality and socio-economic conditions and trends and (5) Place soil quality in a landscape context. Most ecosystem functions depend on connections through time across different parts of the landscape. In conclusion, soil quality is a necessary but not sufficient indicator of sustainable land management. Its value will continue to increase as limitations are diminished through collaboration between scientists, land managers and policymakers. Published by Elsevier Science B.V.