Getting your soil test results back feels exciting. You hold numbers that reveal what is happening beneath your feet. But staring at those numbers can feel confusing if you do not know what they mean or how to use them.
DIY soil testing has made understanding soil health accessible to everyone. Instead of sending samples to distant laboratories and waiting weeks, people can now test their soil on-site and get immediate answers. This guide will help you understand those results and use them to improve your land.
Importance of Testing for Microbial Biomass
Many people make changes to their soil based on guesswork. They add fertilizers, compost, or other amendments, hoping for improvement. Traditional soil tests measure chemical properties like nitrogen, phosphorus, and pH levels through various methods. These numbers provide useful information but miss the biological side of soil health. Living organisms in the soil drive nutrient cycling, water retention, and plant health.
Microbial biomass encompasses all the living organisms in your soil sample. This includes bacteria, fungi, and other microscopic creatures. Think of it as counting the population in an underground city.
Higher microbial biomass numbers usually indicate more biological activity, which can translate to better plant growth, reduced need for fertilizers, and improved resistance to drought. Lower numbers suggest the soil needs help building its living community.
Understanding the Fungal to Bacterial Ratio
The second key measurement is the fungal to bacterial ratio. Soil contains both types of organisms, but different plants prefer different balances. This ratio helps determine what type of ecosystem exists underground.
Bacteria thrive in disturbed soil and support annual plants like vegetables, grains, and grasses. These organisms multiply quickly and break down fresh organic matter rapidly. Gardens and agricultural fields typically show higher bacterial populations.
Fungi prefer undisturbed environments and support perennial plants like trees, shrubs, and native grasses. Fungal networks extend through soil, connecting plants and moving nutrients over long distances. Forest soils naturally contain more fungi than bacteria.
How to Read Your Numbers In Soil Testing?
Real-time soil testing provides immediate data, but understanding context makes those numbers meaningful. The same soil can show different results depending on season, moisture, and recent weather conditions.
Spring and fall typically show higher microbial activity than summer or winter. Warm, moist conditions help microorganisms thrive. Extreme heat or cold slows their activity. Compare results from the same season to track true changes.
What Good Results Look Like In Soil Testing
Healthy agricultural soil typically shows microbial biomass levels above 600 micrograms per gram. Garden soil often shows even higher numbers because gardeners regularly add compost and organic matter and gardens can be managed more frequently due to their size. Really excellent soil can reach 1000 or higher. These numbers indicate strong biological activity supporting plant growth. However, this is largely dependent several factors including your climate, region, soil type and texture.
Conclusion
Soil microbial biomass testing provides powerful insights when interpreted correctly. These numbers reveal the health of the underground ecosystem supporting all plant growth. Understanding and acting on this information creates healthier, more productive land that requires fewer external inputs while producing better results.
Fred Way has joined forces with APN – the Agroforestry Promotion Network which was founded by Roland Frutig and Lucky Mukasa. He also collaborates with soil stewards and farmers from Kenya, Malawi, Uganda, India and Switzerland.
The group travels throughout Africa to Uganda, Egypt, Nigeria, etc. They have educational centers in Malawi and Uganda. Here they host classes several times a year covering various soil practices to assist local growers by enhancing their farming techniques and improvimg forest function. By utilizing microBIOMETER® in these classes, they are able to highlight the importance of soil biology as well as demonstrate how changes in microbial biomass and fungal to bacterial ratio have positive effects on soil.
Whenever they can, they supply farmers with a microBIOMETER® test kit to allow them to easily test and track their soil’s health. While they are still in the beginning stages, their goal is to be able to provide local areas with kits since they are used to determine how native, natural forests function as well.
Fred performed microBIOMETER® testing in a logged forest that was a primary source for rubber in the late 1800’s until tthe early 1900’s. Currently, locals are removing all dead wood for fuel which is creating a loss of food at the trophic level. They use Indigenous microbial organisms (IMOs) in manure and urine (mostly from cows), molasses and other regenerative practices to stimulate the soil. They have discovered that by using these materials, they are able to kickstart the regenerative system. microBIOMETER® has demonstrated that these somewhat unconventional materials are increasing fungal levels over time while bare soil that previously wasn’t producing is now showing signs of life. Their goal is to emulate what’s happening in the forest for their agriculture food production system.
“The affordability and compatibility of microBIOMETER® as well as the real-time results make it easy to understand and track results over time and see improvements quickly. The addition of microBIOMETER® PRO’s advanced calculations and moisture adjustments are a good addition to the test,” – Fred Way
Recently, the Soil Association team was at Woodoaks Farm in Hertfordshire, England collecting soil samples as part of the AI 4 Soil Health project (AI4SH). Madeleine Silberberg, Project Coordinator, coordinates 13 pilot sites across the continent in partnership with leading European institutions. These sites, covering 11 pedoclimatic regions, were selected based on distinctive soil qualities. The team are using advanced measurement techniques, generating new insights into the health of Europe’s soils, testing the assumptions in their models, and helping determine the best monitoring tools for the future.
Soil Association Farming Advisor, Karen Fisher, shares her experience using microBIOMETER® on this project.
“microBIOMETER® turned out to be a genuinely exciting addition to the toolkit. The first test took me a little while, carefully following the instructions step by step, but once I got into the rhythm the process was surprisingly straightforward. The longest part was waiting for the sample to develop but that slotted in nicely while we collected bulk density samples and soils for lab analysis.
I did have a small hiccup with scanning the first card, but I think my app might have been on the wrong mode, but after that everything worked perfectly. Each scan felt a bit like opening a present. I found myself looking forward to seeing what the next result would show.
It was fascinating to see the different patterns emerging across woodland, permanent grassland, conservation fields and compost. Some results weren’t quite what you might expect, for example, a woodland showing a lower fungal: bacterial ratio than a long-term grass field. It is a reminder that context matters: soil biology reflects both current conditions and land use history, and sometimes regeneration takes time.
These kinds of rapid, field-based tools do not replace lab analysis, but they bring soil life into focus in a way that is both practical and accessible. Over time, repeating these tests across seasons and management practices will help us build a richer picture of soil health and feed into the development of different indicators.”
Senior Farming Advisor Josiah Judson, “‘It was great to be out in the field making sure the tools we’re developing actually make sense on the ground and can support different users. It’s an ambitious goal to map these things across so many different landscapes, but the more data we can get, the better!”
Remember when you needed expensive equipment just to know what’s happening in your soil? Well now that same device you use to scroll social media and read the news can analyze soil health with lab-quality precision.
The Science Behind Your Pocket Soil Lab
Your smartphone possesses something laboratories have relied on for decades: sophisticated optical sensors and powerful processing capabilities. Modern smartphones can detect color variations, light intensity, and chemical reactions through their cameras and built-in sensors. When paired with the right testing reagents and apps, these everyday devices transform into legitimate soil analysis tools.
The principle is surprisingly straightforward. Soil samples react with specific chemical reagents, producing color changes that correspond to different nutrient levels, pH values, or biological activity. Your phone’s camera captures these color variations, while specialized algorithms interpret the data and provide instant results.
What Your Mobile Soil Lab Can Actually Measure
You might wonder what kind of soil data you can realistically expect from smartphone-based testing. The capabilities are more extensive than you’d think:
Real-Time Results That Actually Matter
The game-changer isn’t just the technology—it’s the speed. Traditional soil testing means collecting samples, shipping them to a lab, and waiting days or weeks for results. And by then, growing conditions and microbial communities may have changed completely. Smartphone-based soil lab technology delivers results in minutes, not days. This real-time capability transforms how you can manage your soil health. And the microBIOMETER® can help you do just that.
Notice your tomatoes looking yellow in mid-July? Test the soil immediately and adjust your fertilization strategy that same afternoon. Planning fall amendments for your lawn in Texas? Test multiple spots across your property in a single morning and create a targeted improvement plan.
Getting Started: Your First Mobile Soil Analysis
Setting up your smartphone as a soil lab is simpler than you might expect. The microBIOMETER® includes testing reagents, measuring tools, and a smartphone app that guide you through the entire process step by step. You’ll collect a representative soil sample, mix it with the provided reagents, and use your smartphone’s camera to capture the resulting color changes. The app then analyzes the images and provides detailed reports about your soil’s condition. The testing process is quick and you can see results in 20 minutes.
The Technology Revolution Happening Now
All-in-one smartphone-based devices are becoming preferable for agricultural soil analysis, enabling users to complete self-assessments about soil quality and receive performance reports with actionable insights.
The implications extend far beyond individual gardeners. Extension services at universities across the United States are incorporating smartphone soil testing into their educational programs. Community gardens in both rural and urban areas are using these tools to optimize their growing strategies and share soil health data among members.
Urban gardening isn’t just about growing tomatoes in a small closet. It’s about understanding the complexity of soil microbes in unconventional spaces and utilizing new methods that make city gardening not only possible, but also incredibly rewarding.
Plants with healthy microbial communities in their root zones tend to grow more vigorously and are better equipped to withstand stressors such as drought, pests, and diseases. In urban environments where plants face challenges like air pollution, heat islands, and limited space, this microbial support system becomes even more crucial.
Urban soil faces unique challenges that rural farmland doesn’t necessarily encounter on a daily basis. You’re dealing with:
Start with Quality Organic Matter
Your soil microbes are essentially composting machines, but they need fuel. Add compost, aged manure, or leaf mold regularly. These organic materials provide the carbon and nutrients that feed your microbial community. In cities like Portland and Seattle, many neighborhoods now offer community composting programs—take advantage of them!
Test and Track Your Progress
Understanding your soil’s microbial health doesn’t have to be guesswork. Modern soil testing technology allows you to monitor microbial biomass and the fungal-to-bacterial ratio right from your balcony or rooftop garden. This data helps you understand whether your soil management practices are actually working.
Minimize Chemical Disruption
Synthetic pesticides and fertilizers can disrupt your carefully cultivated microbial community. Instead, focus on building soil biology through organic amendments and natural pest management strategies. Beneficial soil microbes perform fundamental functions such as nutrient cycling, breaking down crop residues, and stimulating plant growth.
A recent study reported by the NIH reveals an intriguing connection between gardening and human health that goes beyond fresh vegetables and exercise. It found that frequent exposure to environmental microbiota, especially through skin to soil contact, diversifies commensal microbiota, enhances immune modulation, and ultimately lowers the risk of immune-mediated diseases.
As more Americans embrace urban gardening & soil health practices, we’re seeing innovations that make microbial monitoring and management more accessible than ever. Whether you’re growing herbs on a fire escape in Brooklyn or maintaining raised beds in a Phoenix community garden, understanding and nurturing your soil’s microbial community will help you grow healthier plants while potentially benefiting your own well-being.
Imagine this: The earthy scent of microbes breaking down leaves in the soil fills the air. Your harvest is complete, the season is winding down, and you’re likely looking forward to a well‑deserved break. But before you prepare for winter, seize the opportunity to assess the health of the microbes in your soil. It will pay off next spring! Testing microbial biomass carbon (MBC) and fungal-to-bacterial (F: B) ratios during autumn sets the stage for healthier, more resilient soils next spring. This proactive step is in your hands, and it’s a crucial one.
Here’s why autumn is the sweet spot for measuring soil biology:
1. Post-harvest tests show the real impact of your management
Sampling during autumn captures the “end-of-season report card” for your soil. It reflects how crops and cover crop management shaped microbial life through the growing season. Studies by Cornell University show post-harvest data shows differences between treatments, with diverse cover rotations supporting higher microbial activity compared to standard fallow fields. In other words, autumn tests provide a clear picture of how your decisions paid off biologically.
2. Results guide action plans for the winter
Nebraska Extension notes that low MBC signals low biological activity and carbon availability—exactly the type of challenge that can be addressed when you act ahead of spring. Autumn is your window to respond before soils go quiet in winter. If MBC trends low, you can jumpstart recovery with practices like:
3. Amendments need time to work
If you know your soil is acidic and requires lime, autumn or manure additions, autumn is the best time to make applications and alterations to the microbial ecosystem. Amending now gives the soil several quiet winter months to equilibrate, ensuring pH is in the right range for nutrient availability and microbial activity by the time you plant again.
4. Fall testing builds valuable trend data year over year
Soil health is about direction, not just snapshots. Measuring MBC and F: B ratios every autumn lets you to track whether regenerative practices are truly building biology year after year. That trendline is powerful for farmers, researchers, and anyone looking to prove results.
Final Takeaway: Think of fall microbial testing during autumn as giving your soil a health check before it goes to sleep. You’ll capture a clear understanding of how the season’s management impacts microbes and receive the insights you need to act. When spring rolls around, and microbial life ramps up, you’ll be ready with soils that are biologically prepared for partnering with plants in helping them grow.
Prolific Earth Sciences is excited to announce the release of microBIOMETER® PRO. This extensive update has been three years in the making and features improved precision, increased consistency between phones, advanced nutrient metrics and sample geolocating. Please update your microBIOMETER® Reader app to 3.8.6 to access the PRO version.
What’s NEW!
• Test card. We redesigned the test card to reduce variance in results between phone models and better adjust for different lighting.
• Results. The results are now expressed as microbial biomass instead of microbial carbon.
• Moisture: We have changed the moisture assumption in our algorithm from 40% to 20% which is more in line with average soils. We also added a feature to allow users to adjust the moisture assumption to reflect soils with moisture contents closer to 10% or 30%. Moisture assumption for compost testing remains at 40%
• Geolocation: This new feature allows users to save the location where their sample was collected and perform the test at a later time while keeping the recorded sample location.
• Advanced Nutrient Metrics: As an understanding of how microbes contribute to nutrient availability increases, we have added calculated metrics to help users understand how their soil microbes are contributing to nitrogen and carbon stores in the soil. These are results extrapolated from microBIOMETER® results and the calculation and assumptions are detailed in the app informational pop-ups and our website FAQs.
• Soil and Compost: The PRO version will test both soil and compost, however, will no longer support direct testing of compost tea or extract.
With the exception of the test cards, all the supplies as well as the instructions will remain the same whether using the Classic or PRO version. The updated app will prompt you to choose a version so you can still use the classic test cards. We will also be selling Classic cards in refills for the foreseeable future. However, all new Starter Kit purchases will now be the PRO version only and contain the new test cards. For customers with ongoing trials, you may want to continue with the Classic test cards to track changes based on historical benchmarked tests.
In the updated app, we have made significant changes to units, underlying assumptions, and calculations. Therefore, we encourage users to continue with one version within a study or experiment since comparing the absolute values of the two is difficult. We have always encouraged using microBIOMETER® as a benchmark test and to focus on the changes over time. We will continue to supply the microBIOMETER® Classic test cards so that ongoing studies and trials can continue. However, we strongly recommend using the PRO version for all new testing and studies.
We would like to thank all of our customers that have given us feedback over the years. Your comments, both good and bad, have helped us improve the microBIOMETER®. Please keep sharing! And as always, we appreciate your continued support.
Bucknell University is a private liberal arts college in Lewisburg, Pennsylvania with excellent research facilities and innovative teaching. Students get the opportunity to work closely with professors in their chosen field.
Students in the Biology 203, Integrative Concepts in Biology, laboratory have a unit all about soil. The students visit the Bucknell Farm to learn about the properties of healthy soil. They then pick a location on campus to study. Students study the health of the soil in different conditions, such as soil with native flowers growing compared to soil under a tree. They measure microbial biomass, soil respiration rate, and various other soil properties to determine the overall health of the soil.
“The microBIOMETER® test allows students to quickly and easily measure microbial biomass and the relative amounts of bacteria and fungi in the soil. It is easy to use for non-experts with very quick results! We have measured huge differences in the microbial biomass at locations across Bucknell’s campus and have been surprised to have very high levels of biomass in the grassy areas, too!” – Rebekah Stevenson, Director of Core Course Laboratories – Biology Department
American BioChar Company is a Michigan-based company run by longtime green industry couple, Mark & Laurie Mann. For more than two decades, they have been researching and developing programs and products to improve soils, root conditions, and plant growth in urban, rural, and agricultural landscapes.
Over the last 3 years, they have conducted trials on blueberry farms in SW Michigan, using the microBIOMETER® and other soil-metric tests. The trials compared soils of blueberry bushes treated with their VITAL Blend soil amendment to those with untreated soil. Data was collected in the spring, summer and fall each year to demonstrate the natural ebb & flow of microbe communities in soils. Not only does the data show the steady increase of soil microbial biomass, but overall the trial sites have improved soil structure and more nutrient dense crops.
“The biggest impact we have in using the microBIOMETER® is demonstrating the successful transformation within the soil, following applications of our different biochar blended soil amendments. It provides confidence in our product and helps move the client conversation toward the biological benefits of our product. When a client is able to see and track the fungal to bacterial ratio for their soil overtime, it is very empowering.”
American BioChar is also undergoing several other trials throughout the mid-west with corn, cannabis, soybeans, and tree rhizospheres, using both their VITAL Blend and their new GRATEFUL Blend living soil. As both blends provide active and fixed carbon to soil, these trials were aimed to enhance and increase soil biology and restore nutrient density. Pre- and post- application photos can show how these products improved overall crop production.
Recently, Laurie Mann and microBIOMETER® president Laura Decker participated in Heart & Soil Magazine‘s Soil Summit discussing “How to Increase the Speed of Microbe Growth”. Click here to watch!
Overton Environmental Enterprises, Inc. is a Canadian company that develops innovative biotechnology solutions that reduce reliance on chemical fertilizers and pesticides.
Their EcoTea™ products and research are focused on helping farmers work with soil ecosystems instead of against them. In their years of research they have proven direct results from using broad spectrum biology but the impacts in the soil and changes in soil quality have been harder to showcase.
Three seasons ago they discovered the microBIOMETER® testing system. These tests have given them a way to benchmark pre application conditions, the post application changes and most importantly the improvements over time. This real-time way for farmers to see the unseeable has given them confidence in the value of biology for their soils and programs. They use microBIOMETER® to augment field data (i.e. help correlate scores with plant health data and yield). microBIOMETER® has allowed them to show how EcoTea™ can influence root bacterial to fungal ratios and determine (at least in part) the amount of resources the plant is allocating to the rhizosphere.
The microBIOMETER® has given us another way to showcase how re-introducing biology can help our soils and the hard-working communities that rely on them.”
EcoTea™ is a biological product with biodiversity like no other, built on the vision of soil biodiversity enhancing professional success. EcoTea™ combines a wide array of plant-supporting microorganisms fortified with added biostimulants to enhance soil quality and nutrient function. Diversity is the key, allowing our products to adapt and meet your individual site needs, based on plant response and requirements. Our proprietary process built with ecological engineering provides the functional microbial community associated with healthy crops and soil.
