We are using DNA data to develop novel metric, or indices, of soil ecological health and potential fertility. Biotic indices, based on macroinvertebrate community data, are widely used to score the health of a wide variety of both freshwater and terrestrial ecosystems. Until recently, microbial community data has not been used for such purposes, but advances in high throughput DNA sequence analysis mean that it is now possible to simultaneously identify the taxonomic identity of thousands of species within hundreds of DNA samples. The relationship between each soils microbial community attributes with measures of land use intensity and soil chemical and physical measures is being used to define a variety of microbial community variables that will enable us to effectively ‘score’ the health of any soil environment based on assessments of its microbial DNA.
We foresee these microbial methods being used in the routine analysis of soil health by regional councils and land managers across the country. Specifically, our analysis of microbial community data provides:
- a more sensitive measure of environmental change than commonly used soil chemical measures.
- a more rapid response to environmental change, allowing us to respond to declines in soil health and fertility at an earlier stage, before degradation is severe, or perhaps irreversible.
- a more relevant indicator of changing environmental conditions, since soil microorganisms only respond to the bioavailable nutrients/ pollutants.