Monitoring soil quality of arable land: Microbiological indicators

The aim of this review is to present a foundation of present knowledge and to describe existing strategies for the development and implementation of monitoring systems for soil quality of arable land, based on soil-quality indicators. In the review viewpoints are discussed on the soil-quality concept, suggested frameworks for its assessment, and possible methods for the selection and evaluation of quality indicators. These sections are in general terms, without emphasis on chemical, physical or biological soil properties. The potential value of including microbiological indicators in a monitoring system is discussed thoroughly. Several possible microbiological indicators are suggested, and their advantages and disadvantages are discussed. Strategies for the selection and sampling of monitoring sites are reviewed, and the treatment of samples before analyses is also discussed. In conclusion, a framework for using microbiological indicators in a Swedish monitoring system is suggested.