microBIOMETER® is a rapid, on-site soil test that measures soil microbial biomass and fungal to bacterial ratio (F:B) using patented smartphone technology. It can be used directly on soil and soil-based compost. The app features sample geolocation and cloud-syncing ability, enabling growers and consultants to visualize and track the success of their soil health.
Soil microbes produce a natural binding substance that connects soil particles and forms stable aggregates. Our patented method extracts these microbes from the bound soil, allowing the heavier particles to settle while the soil-colored microbes remain suspended in the fluid. This suspension is then sampled and placed on a test card, which is scanned using our smartphone application (compatible with iPhone and Android).
The app measures the color intensity of the microbes against a color comparator on the test card, providing lab-grade results. Microbial biomass is reported as micrograms of microbial carbon per gram of soil, while fungal-to-bacterial ratio is displayed as F:B, F%, and B%. For detailed instructions, download our guides for Soil and Compost Testing and Compost Tea and Extract Testing, or watch our step-by-step video tutorial.
The microBIOMETER® is best used to obtain a baseline level of your soil followed by comparative experiments to determine efficacy of a product or management practice. The test acts as a dashboard or gauge that shows where growers start, where they are throughout the season, and where they are at the end of the season.
Monitor results of the same field over time or different fields at the same time to show how effective a management approach is at increasing the microbial biomass of the soil. Being consistent with testing and sampling conditions (i.e. lighting, device type, etc.) will allow for greater accuracy when interpreting data. Click here for more testing and sampling tips.
A soil probe or auger is ideal for taking soil samples. If you don’t have a probe, you can use a sharp spade, long knife, or trowel — just be sure sample size is consistent.
The microBIOMETER® can be used directly on soil, soil-based compost, compost tea, and compost extract. It cannot be used directly on soil amendments or soilless growing mediums including but not limited to:
Depending on your goals, microBIOMETER® can be performed in a variety of scenarios. Keep in mind microbial life has natural, seasonal fluctuations, therefore, it’s important to understand and establish a baseline of your soil. We recommend testing a few times each season, before and after harvest, and after hard frost hits to better understand these seasonal changes. Please note that these are general recommendations and timing will differ depending on your soil type.
By comparing microBIOMETER® results over time, you’ll easily identify if your management approach is successful. An increase in F:B ratio and microbial biomass indicates the effectiveness of your amendments and management practices. Click here to view a general interpretation guide.
Copyright © 2025 Prolific Earth Sciences- All Rights Reserved.