There are many soil tests on the market so it can be difficult for farmers to ascertain whether or not they’re choosing the right one. The truth is, there are pros and cons to every soil test. Therefore, it boils down to finding which ones align best with your farming goals and which are easily and readily available to you without needing to stretch your resources too much.
Since microBIOMETER® is a relatively new soil test on the market, questions are often raised on how this test compares to other commonly used soil indicators such as the Haney Soil Test and PLFA test.
Bright Endeavors Now (BEN) located in Tanzania, East Africa was started by Biology professor Dr. Regina Herbert, PhD and her husband, an Electrical Engineer, Ricardo R. Herbert, MUP, MBA.
The BEN program provides an environment where budding engineers, designers, scientists and doctors are introduced to concepts in the sciences, technology, engineering, art and math (STEAM), through engaging, developmentally-appropriate activities.
There are many soil tests on the market so it can be difficult for farmers to ascertain whether or not they’re choosing the right one. The truth is, there are pros and cons to every soil test. Therefore it boils down to finding which ones align best with your farming goals and which are easily and readily available to you without needing to stretch your resources too much.
Since microBIOMETER® is a relatively new soil test on the market, a lot of questions are raised on how this test is different from other commonly used soil indicators such as the Haney Soil Test and PLFA test. While all three are soil biological health tests, their methodologies are very different and the tests measure different parameters.
The microBIOMETER® is an on-site soil test that measures the microbial biomass and fungal to bacterial ratio of living and dormant bacteria and fungi. The test process works by measuring the color intensity of the microbial solution created and comparing the color to the test card comparator. This patented, colorimetric analysis process is generated through our microBIOMETER® Reader App and produces results within 25 minutes of starting the testing process. Test prices range from $13.50/sample to $6.75/sample. The low cost, rapid result detection, and on-site testing of living soil are what makes this test stand out against others. The microBIOMETER® has a slightly limited scope, however, as it’s only able to measure the overall biomass of fungi and bacteria. It does not differentiate between microbial species nor does it measure any other parameters.
The Haney Soil Test is a lab test that focuses on assessing a variety of soil parameters such as pH, microbial biomass, water extractable organic carbon and nitrogen, soil respiration, and inorganic plant available nutrients such as NPK. This test uses multiple methods in order to obtain results, including the Solvita CO2 Burst test to indicate soil microbial respiration and biomass, and the use of unique soil extracts to determine organic and inorganic nutrient availability. While this test offers a large array of soil parameters, there is controversy in the science community about using the Solvita CO2 Burst test methodology as a way of accurately predicting microbial biomass. This is because the soil is dried then rewetted to trigger a release of CO2 to measure microbial activity. Drying soil decreases microbial biomass, and while rewetting it will increase biomass again, it doesn’t necessarily repopulate back to the original microbial composition. The Haney Soil test is offered at several labs throughout the country and recommendations are included with results. Generally, this lab test costs about $50/sample and takes about 3-4 weeks to receive results.
The PLFA Soil Test is a lab-based technique that analyzes phospholipid fatty acids (PLFA), which are found in the cell membranes of living organisms, to determine an estimation of living microbial biomass, fungal to bacterial ratio, and to identify the general presence or absence of microbial functional groups in bacteria, fungi, and protozoa. For this test, labs first dry the soil overnight then use multiple solvents to extract fatty acids from the sample. Then, mass spectrometry is used to identify the sample’s microbial composition based on specific PLFA biomarkers. This testing process takes a few days to complete and generally costs about $60/sample depending on the lab. It is one of the most utilized testing methods since it gained popularity in the late 80’s. Since then, it was discovered that some of the PLFA biomarkers used for identification aren’t limited to one microbial group, therefore making it difficult to determine the accuracy of some results.
The value of each of these tests is to determine a baseline assessment of your soil health. The information obtained from any of these tests will help you gain a better and more rounded understanding of what’s happening in your soil.
David Purdy, Territory Business Manager at John Deere and Soil Health Specialist, utilized the microBIOMETER® soil test in his study titled Assessment of the mircoBIOMETER Soil Biology Test for Agrovista LTD.
Background:
There is an increased level of interest in soil health and a greater demand for more analytical approaches, in particularly for soil biology, for its assessment from farmers and advisors. This short report reviews the use of a recently developed rapid on-site soil microbial carbon testing tool called microBIOMETER® using a replicated 5 year cover crop experiment.
Location:
The experiment was carried out at the location of the Agrovista LTD. trials site is near Lamport in Northamptonshire about 8 miles north of Northampton in the UK. It has a longitude of 52.372234, and latitude of -0.874273. The field site history is of arable farming rotations on a slightly southerly sloping topography.
“The tests, although time consuming, provided an “in field” test that when conducted well seems to suggest it is a reliable, consistent, replicable, and relatively simple test to evaluate soil biological activity.” – David Purdy
Founded in 2008, Applied Bio-Minerals, Inc. specializes in managing naturally present microbiomes using mixtures of mined minerals.
The company’s operating mode is based on observations, and a close collaboration with the customer. The holistic approach enables farmers to use microbes already present on their farm to their benefit by lowering their inputs and maximizing their revenues, all naturally. As part of the service provided to customers, the company regularly measures progress to ensure the farmer’s goals are met.
Their approach is to examine the entire living soil profile and record its evolution from a baseline set before the application of products. Among the many variables one is essential, the amount of living micro-organisms, and the ratio between bacteria and fungi, at various soil depths.
That is where microBIOMETER® comes in. They have been utilizing the microBIOMETER® soil test in their business since 2020.
“microBIOMETER® is a very convenient tool to have a quick result (in the field) on microbes and allows decisions and adjustments in conducting the field as the season progresses or from one season to the next. Microbial life might sometimes be surprisingly active in depth (here a vineyard). The importance of checking compost quality also underlines the usefulness of the microBIOMETER®” – Herve Bonin, co-founder and managing partner of Applied Bio-Minerals, Inc.
About Applied Bio-Minerals, Inc.
Data from Applied Bio-Minerals, Inc. customer in Virginia
We first had the pleasure of working with Briana Alfaro and Soul Fire Farm in 2021 when they began testing soil with farmers in their network as part of their SARE research project, Soil Carbon Capture for Diverse Farmers; Black, Latinx, Asian, Indigenous and other farmers and farm workers of color take the lead in testing soil carbon sequestration strategies and measurement protocols and disseminate those findings to the farming community in both English and Spanish.
Every two years the Soul Fire Farm team takes a closer look at the soil ecosystem and assesses how healthy their soil is. They do this by performing a series of in-field tests. Long before the western study of soil science, Indigenous communities practiced–and still practice–methods of evaluating soil health using characteristics such as color or the presence of specific plants or insects that tell us something about the system as a whole. On their soil testing days, they count the number of earthworms, perform a slake test to observe aggregate stability, look at soil color as an indicator of organic matter, and use the microBIOMETER® field kit to assess soil biology.
You can learn more in their Guide to In-Field Soil Health Measurement Protocols: How Alive is My Soil (English) & ¿Qué tan vivo está mi suelo? (Español), and by watching their Liberation on Land skill share videos: Soil Carbon part 1, Soil Carbon part 2 & Investigating Soil with an Auger.
BioHub Solutions, an Australian company that provides biological solutions to the agricultural industry, has incorporated microBIOMETER® into their business. BioHub Solutions believes measurements should be simple whenever possible to ensure their implementation and repeatability. microBIOMETER® has become an integral part of the BioPlan processes. Growers also like it because it provides instant feedback and accountability for Biohub’s biological strategies.
“Our trees continue to do well against the control in areas such as average plant height growth, trunk to height ratio, and fungi to bacteria ratio utilizing microBIOMETER®. This is pleasing so far and we will continue measurements.”
Green bean study in North Queensland.
Green bean trial in North Queensland (above). Initial samples taken 2 weeks before harvest. So far overall bean numbers are 36% improved over control. More importantly, marketable sized numbers are improved by 52%. This is where the margin is for the grower. Microbial biomass is also 28% higher than control which is pleasing. Looking forward to the full harvest figures if they reflect the initial samples taken.
Olive rootstock (below). The data has indicated on average, a 17% increase in stem diameter over the control. Root weight improvements of 47%, biology biomass improvements of 46% and fungal to bacterial ratio improvements of 56% over control. This illustrated that the BioHub solution achieved results in the manner the team had predicted. Photo depicts an example of the treated plug on the left and control on the right.
Olive rootstock – treated
Olive rootstock – control
Andrew Turnbull is the owner of SouthWest Agronomy Ltd (SWA) located in Tavistock, England. His company offers advisory and consultancy services to golf courses and sports turf facilities.
One issue the company faced was how to prove to their customers that their recommended treatments were actually having a positive influence on the soil microbes. Other than the obvious visual effects of the quality of the playing surface, which can often be open to interpretation, Andrew wanted to prove that other factors have improved performance such as extra or different maintenance operations. Andrew found regular soil microbial analysis to be expensive with only a few laboratories locally performing accurate testing.
“microBIOMETER® changed the game!” – Andrew Turnbull
Now, in addition to comprehensive nutrient and microscopic analysis, the company incorporates regular microbial testing with microBIOMETER® into their program. This enables them to give their clients confidence that they are implementing changes that not only have a positive visual effect, but a measurable and direct one as well.
About SouthWest Agronomy Ltd (SWA).SWA focuses on the little understood aspect of how turfgrass plants interact with the rootzone biology and how the plant’s metabolism is affected by biotic and abiotic stresses. When a turfgrass plant is healthy it excretes carbohydrates, proteins and other exudates that feed microbes. This increases mineralization of nutrients, enhances disease protection, and causes organic matter recycling. SWA’s Bio Nutrition Program restores the balance between the plant and soil microbes which is lost when turfgrass management relies on chemical fertilizers, and/or is under continual stress from maintenance operations, and/or has less than optimum environmental conditions (e.g. heat, cold, shade), and regular use by players.
Kenley Mitchell, a 5th grader at Sargent Elementary School, utilized microBIOMETER® in her science fair project titled “Getting Dirty: Does Soil Affect a Dog’s Microbiome?” Kenley won first prize in her category and received the overall best project award for the San Luis Valley Regional in Alamosa, CO!
Project Abstract:
For my project, I tested a dog’s microbiome and compared it to the health of the dog’s soil. I also looked at the time the dog spends in the soil. I ran two samples. The first sample was a stool sample. The second sample was a soil sample. Both were taken at the same time. I tested dogs that are in the city vs. country dogs. I found out that farm dogs have a healthier microbiome, but city dogs have healthier soil. The farm dogs’ average microbial biomass in the soil is 221.0 ug C/g. The city dogs’ average microbial biomass in the soil is 273.4 ug C/g. Farm dogs average for F% is 20%. City dogs average for F% is 32%. Farm dogs average for B% is 80%. City dogs average for B% is 68%. The farm dogs were outside in the soil for longer periods of time. The farm dogs might be healthier due to spending more time in the soil.
Francis Lawton an 8th grader at St. Timothy School in Los Angeles, CA utilized microBIOMETER® in his science fair project titled “The Effect of Greywater on Plant Growth, Soil Microbial Biomass Carbon, and Soil Fungi to Bacteria Ratio. Francis took first prize at the fair and moved on to the Los Angeles County Science & Engineering Fair where he placed 3rd in his category of Ecology. He also received a special award from USAID (U.S. Agency for International Development). Francis then took part in the California State Science & Engineering Fair in the category of Earth & Environment (Air/Water) and placed 2nd!
Have a science fair project coming up and would like to incorporate microBIOMETER®? Please contact us!
Project Abstract:
This project was designed to find out if greywater and treated greywater can safely hydrate plants, and promote plant growth, just as well as tap water. I live in drought-prone California and it’s important to find different ways of conserving water. My experiment tested the watering of grass pots with three different types of water (independent variable): Tap water, Greywater, and Greywater treated with Activated Charcoal. Over the course of 8 weeks, I measured plant growth, soil Microbial Biomass Carbon (MBC) levels and soil Fungi to Bacteria (F:B) ratio (dependent variables). Many controlled variables ensured a valid experiment. I hypothesized that each of the water types would result in the same growth rate, soil MBC and soil F:B ratio. My hypothesis, however, was incorrect. Greywater resulted in stunted growth and spiked the F:B soil ratio so high that the pot sprouted 13 fungi heads. Tap water and Treated Greywater, however, were equally good in terms of healthy plant growth and both pots had the two best average F:B ratios closest to 1:1 (which is the best ratio for grasses). Neither of these pots produced fungi. Soil carbon levels (MBC) fluctuated for all three plants, however each plant maintained an “Excellent” level. This indicated that each water type was fine for watering grass if you don’t mind stunted grass growth and some fungi in your lawn. My experiment also proved that Activated Charcoal effectively “adsorbs” chemicals in greywater that alter a soil’s F:B ratio.
