Identification of sensitive indicators to assess the interrelationship between soil quality, management practices and human health

Abstract

Abstract. Soil quality (SQ) assessment has been a challenging issue since soils present high variability in properties and functions. This paper aims to increase understanding of SQ through review of SQ assessments in different scenarios providing evidence about the interrelationship between SQ, land use and human health. There is a general consensus that there is a need to develop methods to assess and monitor SQ for assuring sustainable land use with no prejudicial effects on human health. This review points out the importance of adopting indicators of different nature (physical, chemical and biological) to achieve a holistic image of SQ. Most authors use single indicators to assess SQ and its relationship with land uses, being the most used indicators soil organic carbon and pH. The use of nitrogen and nutrients content has resulted sensitive for agricultural and forest systems, together with physical properties such as texture, bulk density, available water and aggregate stability. These physical indicators have also been widely used to assess SQ after land use changes. The use of biological indicators is less generalized, being microbial biomass and enzyme activities the most selected indicators. Although most authors assess SQ using independent indicators, it is preferable to combine some of them into models to create a soil quality index (SQI), since it provides integrated information about soil processes and functioning. The majority of revised articles used the same methodology to establish a SQI, based on scoring and weighting of different soil indicators, selected by multivariate analyses. The use of multiple linear regressions has been successfully used under forest land use. Urban soil quality has been poorly assessed, with lack of adoption of SQIs. In addition, SQ assessments were human health indicators or exposure pathways are incorporated are practically inexistent. Thus, new efforts should be carried out to establish new methodologies not only to assess soil quality in terms of sustainability, productivity and ecosystems quality, but also human health. Additionally, new challenges arise with the use and integration into SQIs of stable isotopic, genomic, proteomic and spectroscopy data.