One of the most important topics in soil science is understanding the relationship between soil biodiversity and soil ecosystem function. This relies on techniques able to accurately identify different soil organisms and how they interact in the soil microbiome. Measuring and assessing the biological health of soils provides a comprehensive overview of the range of techniques used to assess microbial/faunal diversity and activity in soils and its impact on key ecological processes. The book also reviews how biological indicators can be integrated into soil health testing programmes to improve the quality of agricultural, grassland and forest soils. The book builds on a successful earlier volume published by Burleigh Dodds Science Publishing: Advances in measuring soil health (2021).