Detecting vegetation stress as a soil contamination proxy: a review of optical proximal and remote sensing techniques

Soil contamination is a worldwide crisis, which diminishes food and agricultural production. Alterations in the soil environment due to soil contamination cause biophysical and biochemical changes in vegetation. Due to dynamic nature of these changes, early monitoring can permit for preventive interferences before intense and sometimes inevitable vegetation and soil problems occur. As plants are rooted in soil substrate, vegetation changes can be used as bio-indicators of soil conditions. Traditionally, vegetation changes have been usually determined by visual analysis or detected after major destructive sampling during the growth period. As the characteristics of vegetation influence its spectral properties, effective remote and non-contact detection methods offer an alternative and near real-time way for detecting plant changes, even prior to visual symptoms and negative effects appearance. The aim of the current study is to review the potential of optical proximal and remote sensing techniques at different platforms for indirect assessment of plant–soil interactions via monitoring vegetation anomalies related to soil contamination. It is strongly felt that this rapidly progressing technological direction will permit extending the use of the techniques to geology, soil science and precision agriculture and an overall broad range of applications.