Soil Biology As Part of Soil Health: Where Art Thou?.

Soil health has been a topic for many decades if not centuries. Many physical and chemical parameters exist for assessing soil health; however, there has been no consensus of soil biological measures. It is generally accepted that soil biology is the driver for nutrient cycling and sustainable agriculture.  Earthworms which are held up as the poster child of soil health is an invasive species in North American soils.  Measures of soil biology are complicated by temporal variability.  Soil water and temperature override many dynamic measures of soil biological activity. This temporal nature complicates time of sampling for soil health.  Traditional measures for soil biology only account for less than 5% of the soil microbial community. Newer measures of soil biology for community diversity may afford opportunities for inclusion into soil health assessment.  The questions are what are the appropriate biological measures of soil health and what are the quantitative indices for soil health assessment.  Ultimately soil health needs to consider productivity, resilience, and diversity.