Rick Haney: microbial activity in soil analysis
Plant nutrition depends partly on organisms transforming organic matter and releasing nutrients. USDA–ARS soil scientist Rick Haney developed a test combining chemical measures with biological activity indicators.
What the Haney Test examines
It measures inorganic nitrogen, water-extractable organic carbon and nitrogen, and microbial activity. H3A, an organic-acid extractant, estimates extractable nutrients. Together, measurements describe links between organic matter, biology and nutrient availability.
Respiration as an activity indicator
Part of the test measures carbon dioxide after rewetting a dried sample in a controlled incubation, usually 24 hours. This captures the community’s respiratory response under the protocol’s conditions.
Different measurements provide different information
Respiration describes activity; microscopy examines group presence, abundance and morphology. These can complement one another. High respiration alone does not reveal dominant organisms or whether the community suits the crop.
From measurement to interpretation
Different extractants and protocols require their own evidence-based interpretation scales. Minnesota comparisons found different nutrient estimates and fertiliser recommendations between Haney and conventional tests. Researchers emphasise calibration for local soils and crops.
Repeated use of the same method and comparable sampling helps track responses over time.
Our field work
We aim to explore activity indicators alongside soil analysis, Soil Food Web microscopy and olive grove responses to applications.
Sources and further reading
- USDA ARS, Reducing Fertilizer Needs by Accounting for Soil Microbes
- Comparing Biological and Conventional Chemical Soil Tests in Long-Term Tillage, Rotation, N Rate Field Study
- University of Minnesota, Can soil health tests determine fertilizer needs?
- University of Minnesota, Soil health lab test quick guide