I got this from the SFI website. This tells us exactly what the tests measure and what the findings will tell us about the samples.
The total biomass test will show all bacterial and fungal levels including, but not differentiating it from the active totals.
Interpretation is free if payment is sent with the sample.
Active Bacteria/Active Fungi:
These tests measure the presence (numbers, biomass) of bacteria and fungi that are actively feeding and reproducing. Active bacteria and fungi rapidly enhance soil structure, nutrient retention, disease suppression and residue/pollutant decomposition.
This test is used to determine:
* Is nitrogen being retained against loss at this time?
* Is this soil dominated by the influence of fungi or bacteria at this time?
* Is there a decent food supply to support other types of microbes in the foodweb that feed upon bacteria or fungi?
* Did a product cause a bloom of bacteria or fungal activity that is useful and worthwhile?
* Did an application of a herbicide or other pesticide to soil stimulate or kill either bacteria or fungi?
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Total Bacteria/Total Fungi:
This test measures the total amount of bacteria and fungi, including the active fraction. These tests do not distinguish active from inactive or dead cells, but give the long-term amount of carbon or nitrogen held in these organisms, assess disease suppressiveness, benefits to soil aggregation, and relate to decomposition rates.
This test is used to determine:
* Has the soil been dominated by fungi or bacteria or both in the recent past?
* Is there a pool of retained nitrogen in the form of protein that can be released to plants later?
* What is the size or capacity of the food supply to support higher forms of organisms in the soil foodweb that graze on bacteria and fungi. These higher forms balance the population levels of bacteria and fungi and excrete nitrogen into the soil in the form of ammonium for plants.
