Getting to the Science of Soil Health: USDA Releases Standard Indicators and Laboratory Procedures to Assess Soil Health
There has been a great deal of enthusiasm for improving our nation’s soils since USDA-NRCS launched their national soil health initiative “Unlock the Secrets in the Soil” in April of 2013. As the world population increases, keeping our soils healthy and productive is of paramount importance as the demand for food increases. Farms using the soil health principles that include no-till/conservation tillage, cover crops, and diverse crop rotations are slowly improving their farms soil health. Farmers are increasing soil organic matter, improving microbial activity, aggregate formation, water infiltration, and soil resilience, while often increasing yields and profits.
The enthusiasm for the soil health principles in some cases has gotten ahead of the science behind them. To address this, NRCS and the Agricultural Research Services (ARS) lead a diverse group of technical experts in selecting methods to assess six standard soil health indicators, which focus on key physical and biological process that must function well in healthy soils. Those indicators include:
- Organic matter recycling and carbon sequestration
- Soil structure stability
- General microbial activity
- Carbon food source
- Bioavailable nitrogen
- Microbial community diversity
Laboratory methods for assessing each indicator was chosen based on interpretability, ease of use, cost effectiveness, measurement repeatability, and ability to inform agricultural management decisions.
The document titled “Recommended Soil Health Indicators and Associated Laboratory Procedures”, Technical Note No. 450 (PDF) was developed by a group of experts and provides information getting us closer to understanding the science behind soil health and how it is best measured. The document is currently under review and in the public comment process.
The above document is a good read for individuals interested in learning more about the important soil health indicators and how they are measured. In addition to the document, experts presented an overview of the document in this webinar.