UPDATE: Dr. White sat down with Dr. Fitzpatrick and Jeff Lowenfels to discuss rhizophagy. Click here to view the webinar. (Jan. 15, 2021)
A summary of James F. White’s presentation at BioFarm, 2020 (Nov. 12, 2020).
The rhizophagy cycle is an amazing process recently discovered by James White’s laboratory at the University of New Jersey, by which root tips “ingest” bacteria and absorb nitrogen and phosphorus and other nutrients from them.
The microbes pictured here in roots are called endophytes because they can live inside plants. The bacteria are attracted to the root tip by root exudates. They then enter the root where the cell walls are dissolved using superoxide, allowing nutrients to leak out to the plant. But the plant does not kill the microbes instead the microbes stimulate the formation of root hairs, which are escape routes for the microbes.
After ejection from root hair tips, bacterial cell walls re-form. The bacteria fatten up and are soon ready to acquire soil nutrients and become another meal for the plant.
Source: How Plants ‘Farm’ Soil Microbes and Endophytes in Roots

Not only does rhizophagy provide mineral nutrients, it is also the stimulus for formation of root hairs, which are critical to the establishment of a healthy root as can be seen in this photo of a plant root with and without endophytes.
microBIOMETER® reports the microbial biomass as ug of microbial carbon/gram of soil. The chart pictured here shows how much carbon can be stored in an acre just by increasing microbial biomass alone. (Chemically fertilized farmland averages about 100 ug/microbial C/g of soil.)
Microbial biomass is the best single estimate of soil quality. It is the bodies of dead microbes that build humus/soil organic carbon, returning carbon to the soil and building soil structure which prevents erosion and pollutant run off. (Chemical nitrogen fertilizers have been shown to inhibit microbial biomass.)
The literature reports that lab measurements of soil organic carbon are not sufficiently accurate in monitoring an increase in carbon sequestration in less than 3 years but that a yearly increase in microbial biomass can indicate that the process of carbon accumulation is occurring.
microBIOMETER® has been used to demonstrate increases in soil carbon due to increases in microbial biomass on the Apple campus in Texas and for 3 years by the NYC Arts and Science Carbon Sponge Project.
Katharhy G. is an agroecosystem and ethnoscience researcher who traveled to Ecuador to investigate the relationship between microbial biomass and crop health, as well as to study the local indigenous agriculture practices.
He visited 28 different farms growing 15 different crops. 14 of these farms are practicing conventional farming, while the other 14 farms are practicing indigenous regenerative farming. Most sites are not receiving irrigation. He tested the soil with microBIOMETER® and ranked the crop health as poor (1), average (2), good (3), excellent (4).
As the graph shows, microbial biomass correlated with crop health under all these different conditions. Samples with microbial biomass lower than 225 were all poor (1) and samples above 400 were all excellent.
The take home lesson is that to improve your plant health and yield, increase your microbial biomass by feeding your microbes with organic amendments.
If you have microBIOMETER® research data you’d like to share with us, please contact us. We would love to share it with our readers!
Contact:. ka*******@***il.com
The effect of various Roundup formulations and microplastics on soil.
Dr. Sharon Pochron and her students at Stonybrook University in New York have been using microBIOMETER® for two years. Dr. Pochron studies the effect of various Roundup formulations and microplastics on soil microbes and soil invertebrates.
Her most recent publication (See Figure 2) shows microbial biomass increasing on day 7 in both the Roundup treated and untreated soils – the 0 line depicts the microbial biomass on day 0. This increase is probably due to the soil microbes responding to rewetting. By day 14 the microbial biomass in the uncontaminated soil is back to baseline, but the Roundup treated soil has dropped well below baseline. By day 21 both soils have returned to baseline. This study shows only total microbial biomass recovery, but there is evidence that Roundup can affect microbial composition.
Prolific Earth Sciences is supporting research at various universities. Feel free to contact us to discuss your project and how we can assist.

Mike Ellis of Mt. Hope Farms
We had the pleasure of speaking to Mike Ellis of Mt. Hope Farms as he shared his experience with microBIOMETER®. We also learned a lot about his family farm in Molalla, Oregon.
“Had a great opportunity to take my new microbe test kit out for a spin. It was quick and easy to get results and gave us a great insight into where we are at today. I’ve only run a few tests but it was easy and an invaluable tool to immediately see exactly where we are at, soil microbe wise.
I plan to be using this quite frequently to evaluate how we are doing with our farm/soil stewardship goals. We plan to do testing before and after applications of a number of commonly used products on our farm so we can evaluate if each one is helping or hurting our microbes. This way if we do have to do anything that will hurt them, we can hopefully follow it with products and practices that will help them heal.” –Mike Ellis
About Mt. Hope Farms
Mt. Hope Farms is a multigenerational family farm specializing in growing unique berries such as aronia and haskap as well as table grapes and in making fruit spreads in very small batches. Mike and his wife, Laura, represent the 3rd generation farming this land. Mike grew up farming with his dad, who he still farms with, and his grandpa, until he passed away at 92 (still farming and never fully retiring). Farming is part of the Ellis DNA and even though their boys are still very young, they want nothing more than to be on a tractor or out working in the vineyard or fields. They are truly a family farm and make all decisions together.
For many years, the family farmed larger commodity crops (such as grass seed, wheat, clover seed, radish seed, etc.). While they still grow some of these, namely grass seed, clover seed, and radish seed, they have been working hard to transition over to crops that can be grown on a smaller amount of acreage (requiring less rental ground), take less large equipment and can more easily be grown according to their biological and organic farming standards, making them more sustainable. They also needed to begin switching to crops that would carry through to the next generation, crops that would prove to be long term investments. Crops like their grapes and berries are long-term crops that will still be producing once their two sons are older and ready to take over operations, if they choose to.
All of their food crops have great flavor, are highly nutritious and nutrient dense and are less common than many already found in the Willamette Valley. To achieve this requires a healthy and highly productive soil. The only way that they believe they can consistently hit their yield and quality goals is to pay close attention to the soil fertility and soil microbial health. Every generation of their family has done their best to leave the land better than they have found it, regardless of whether it was rental ground or owned ground. Prior generations did the best they could with the understanding, knowledge, and tools that they had, and Mike is beyond grateful for all that they did. Now it is their turn and they will do all that they can to continue that tradition, not just for themselves but also for generations to come.
Healthy soil is brimming with beneficial microbes, and those microbes are one of the important keys to ensuring the health of your plants. Along with breaking down key nutrients for your plants, they’ll aerate the soil so nutrients are evenly distributed, and fend off parasitic microbes so your garden can grow in peace.
Considering the wealth of benefits, it’s no surprise that it is recommended that you do everything you can to maximize the microbial biomass in your soil. While there’s complicated science behind it, nourishing and increasing the amount of microbes in your soil is simple, and can be accomplished with a few tried and true methods. And thanks to the microBIOMETER® soil test, even amateur gardeners can track their microbial biomass levels.
First, let’s detail how you can take care of those important microbes and enhance their numbers. It’ll involve shedding some old gardening habits, along with taking on some new ones, but we promise the end results will be worth it.
What To Avoid
Before you start taking extra steps to care for and increase your microbial biomass, you should ensure you’re avoiding certain tactics that are known to hinder their growth.
While you might think avoiding pesticides wouldn’t enhance plant health, a close look at the ingredients of most pesticides will show you they do far more harm than good. Amongst a variety of issues, one of the most harmful is the fact they decimate microbial populations in the soil. If you want to ensure pests will stay away in the absence of pesticides, try utilizing companion plants instead.
While pesticides are bad, fungicides are even more of a threat. Some of the most vital microbes in your soil, being fungi, would be directly targeted by these treatments. The harshness of these chemicals would also wreak havoc on the non-fungi microbes, all but eliminating any trace of a microbial biomass. Even if you can’t do everything on this list, ensure you at least abide by this particular rule.
Lastly, while many gardeners and farmers consider tilling a standard gardening process, you’ll want to abstain from it if you’re focusing on your soil’s microbes. That, of course, is due to the level of soil disturbance that occurs during the process. The process leads to lost microbes (especially fungi), and any benefits gained from additions made to the soil end up being cancelled out. By avoiding tilling, you’ll allow the delicate environment in your soil to function undisturbed and, in turn, at full capacity.
What To Do
Now that you’ve cut those bad habits out of your gardening routine, you have room for a few that’ll greatly benefit your soil in the long run.
Nothing gets microbes into the soil like a nice big pile of compost! All that food breaking down in one big pile is basically a feast for all the helpful microbes you want around your plants. Once you add it onto your soil, then turn it to make sure air hits every part of it, you’ll be ensuring the microbes have plenty of energy to break down nutrients. To ensure the best compost possible, make sure you add in natural components like grass clippings, fruits, vegetables, wood chips, and straw. There’s no need to exclude other foods, even processed ones, but a healthy blend of green and brown material is a must.
Following the same logic, compost teas can do wonders for the microbes in your soil. All you have to do is take some compost and put it in a water permeable pouch, add some microbe feeding nutrients (perhaps like molasses), and let it brew (bubbling air into it) until the microbes in the compost have multiplied and the tea is full of microbes. Once done, pour it all around the base of your plants. One round will do your plants good, but repeating this process a few times during your growing process will really make a difference.
This last step is actually three steps and if these conditions aren’t met, virtually nothing else on this list will have a noticeable effect. To start, making sure you have adequate moisture is as simple as regularly watering your plants. You may also want to consider purchasing a moisture meter to assure your levels are ideal. Next, the ideal pH range for soil is between 6.0 and 7.0, so you’ll have to test your soil to see where you’re at. If your soil pH is too low try adding limestone and if your pH is too high you can add aluminum sulfate and sulfur to get things balanced. Lastly, mulching is a great way to help your soil maintain an even temperature.
Incorporating these simple tactics into your crop management is an important first step to building the microbial biomass in your soil. Another critical step is testing and quantifying the results of these inputs since decision making without data is like driving blindfolded. microBIOMETER® is a rapid, on-site soil test for microbial biomass. Microbes respond very quickly to any changes in the soil, therefore, you can set a baseline then retest within a week to see if you are heading in the right direction.
With a small R & D grant awarded from the Dutch government, Jo Ploumen of the Netherlands is using microBIOMETER® to determine fungal to bacterial ratios in vermicompost filled in a Johnson-Su Bioreactor versus residence time. Jo also uses microBIOMETER® to measure microbes and F:B ratio in select soil samples as a member of a garden club. He found the differences by method of gardening; organic vs fertilizer and bare vs covered soil to be striking!
“I like microBIOMETER® as it is a cost-effective tool with a high impact, potentially,” Jo said.
Jo’s impressive resume includes studying Chemical Technology at the Technical University of Eindhoven, employment at multinational AKZO Nobel as an R & D specialist and co-founder of Pulsed Heat BV. In 2019, Jo founded Ploumen E.S. Compost to begin research based on the findings of Dr. David Johnson. Johnson is the developer of the Johnson-Su Bioreactor which delivers a compost with very unique properties.
We are honored to have Jo as a valued customer, data collector and partner on our journey to increase awareness of soil health, regenerative practices and carbon sequestration!
Photo source: Taos News
Microbial biomass (MB) is the best single indicator of soil health (Doran, 2000). Microbes feed and protect plants, build soil structure which prevents erosion, increase water holding capacity, and build soil organic matter (SOM). MB is low in any situation that is harmful to plant growth (and vice versa) and protects against pathogens, thereby reducing the need for pesticides. MB can predict success before plant outcome. The Fungal:Bacterial ratio (F:B) of the MB provides crucial information regarding colonization by Arbuscular Mycorrhizal Fungi (AMF), and the recycling metabolic processes of saprophytic fungi (SpF).
Soil stewards all over the world are seeking to understand the microbial levels in their soil and the ratio of fungal to bacterial life. The higher the microbial biomass, the more nutrients will be available to plants naturally, decreasing or eliminating the need for chemical fertilizers. Higher fungal to bacterial ratios are critical for building soil structure that prevents erosion and runoff off of pollutant chemicals while building moisture holding capacity of the soil and sequestering carbon.
Soil health is fast becoming one of the most important factors in agriculture and in the growing efforts to improve the earth’s stock of agricultural land. Farmers, industry, and environmentalists are looking for cost-effective and reliable ways to measure soil health and to assess impacts of progressive changes to soil and harvest management.
Testing soil in homogeneous sections at similar stages of the growth cycle can set a baseline for microbial biomass and fungal to bacterial ratio. That baseline can be used to assess how different stewardship practices are impacting the soil and allow for refinement to soil management plans and show soil health improvement over time. While every soil steward’s situation is unique, microBIOMETER® can help measure, follow, and assess efficacy of improvement to soil health.
Many first-time cannabis growers don’t think too hard about the soil their plants will be growing in. If the soil looks healthy enough, it should be good to go, right? Well, it might be, but that isn’t enough information to tell for sure. If you really want to know whether your cannabis will thrive, you’ll have to see whether or not your soil contains a solid amount of microbes.
Microbes have a mutually beneficial relationship with the plants in their soil, and supporting microbes is one of the best ways you can support your cannabis. As we go along, we’ll be discussing the details of microbial presence in soil, the relationship between microbes and plants, and the specific organisms that make optimal growth possible.
Why Microbes Play a Vital Role in your Cannabis Plant Health
Microbes are key if you want your cannabis plants to grow as well as they can. If the idea of beneficial bacteria is strange to you, remember that we, ideally, have loads of bacteria in our bodies that keep us healthy. We’re not made of soil, of course, so things don’t work exactly the same, but the microbes in soil and those in our guts share key functions in common. Namely, as we’re about to explore, microbes provide vital nutrients to the plants in their soil, along with protecting them from harmful forces.
How Microbes and Cannabis Plants Work Together
With that in mind, let’s take a look at how the relationship between microbes and the cannabis plants you are growing play out in the soil. Plants need sufficient amounts of phosphorus, potassium, and nitrogen to survive and microbes have a direct hand in how much of those nutrients your plants receive.
While the nutrients may be in the soil already, they aren’t as accessible as they could be. Potassium, for example, is often shrouded in inorganic material. As microbes happen upon it, they’ll consume it, metabolize it, and excrete it in a form much more readily consumed by the plants. While the others aren’t as hard for the plant to get to, the microbes break them down nonetheless, and the plants benefit greatly from the enhanced access. This effort is further assisted by their ability to aerate the soil, ensuring there’s an even flow of water and nutrients.
The microbes aren’t only doing all this from the goodness of their heart, though. As the plants are fed, their roots excrete a collection of substances, called exudates, into the soil. These exudates, which include a variety of amino acids, organic acids, and sugars, happen to be a great source of nutrition for the microbes. With their microbe bellies full, the nutritional cycle is fully formed, and the plants are ready to thrive.
The Importance of Fungi for Growing Cannabis
While we think of fungi as separate from microbes, they’re part of the club too, and serve the same cause. To be clear, though, this is because they also partake in the exudates to stay fed.
Mycorrhiza fungi, in particular, can be found acting as the extension of plant roots, collecting nutrition from further down the soil than plants would be able to otherwise.
One type, ectomycorrhizae, acts as a sort of sheath for the root, extending out for nutrition. Endomycorrhizae, however, actually live inside the plant, helping to bring the nutrients straight into the root. To preserve them, ensure that you’re not being heavy-handed with fertilizers. Of course, you should also avoid fungicides entirely.
Microbial Dangers, and How Other Microbes Stop Them
As the fungi provide nutrients to the roots, they serve as a protective layer for them as well. But what, exactly, do they need protecting from? Well, among the beneficial microbes, there are thousands of microscopic worms, called parasitic nematodes, that feed on the roots of plants.
Looking from the outside, you’d notice roots facing attacks from ectoparasitic nematodes, which live in the soil right outside said roots (the rhizosphere). At the same time, endoparasitic nematodes are able to enter the roots themselves, breaking them down from the inside.
In anticipation of this threat, fungi will utilize their hyphae, which are the tiny strands that make up their mycelium. Using these strands, the fungi are able to locate and trap both types of nematodes, preventing them from further chewing at the root.
The fungi also receive help from, interestingly enough, other nematodes. They aren’t quite the same, though; while the others are parasitic, these are known as predatory nematodes. They, too, dwell in the rhizosphere, but only to eliminate plant-eating threats in the area.
How Earthworms Play a Part
Not every part of this underground battle is microscopic, though. In fact, the humble earthworm will be one of the main lines of defense for your cannabis plant. Parasitic nematodes happen to be a favorite prey of theirs, so they’ll munch up whatever your fungi and other microbes can’t catch. In turn, the waste they excrete contains nitrogen, phosphorus, and potassium (the three vital nutrients we mentioned earlier), along with calcium and magnesium. They also aerate the soil as they move around, ensuring the plant has easy access to the natural fertilizer.
How Benefits Show Themselves in Cannabis Plants
If you’re able to ensure optimal conditions for your soil microbes, you’ll notice it pretty quickly as your cannabis plants mature. Their leaves will be greener and fuller, they’ll end up on the taller side, and your buds will be notably larger and more resinous than average.
Your plant may be able to survive without a healthy amount of microbes, but it’ll look amateur in comparison. That’s not to mention the cost of those seeds adding up, leading you to lose money you could spend on expanding your growing operation. Armed with this new information, you won’t even have to worry yourself with the thought. Just keep those microbes and worms alive, and you’ll be on your way to hefty yields of potent buds!
microBIOMETER®, a rapid, on-site soil test, will help you determine the microbial levels in your cannabis soil as well as the fungal to bacterial ratio to ensure the healthiest environment for optimal growth of your plants.
Until now tests for microbial biomass were expensive and time consuming. microBIOMETER® costs $13.50 or less and takes 20 minutes with results read by your cell phone.
* Only microBIOMETER® identified soil health in a U. of Tennessee study of soil health test methods including Cornell, USDA, Alabama and other soil health panels costing ten times as much.
* There are >2 million academic articles that use microbial biomass laboratory tests as proof of soil health. However, lab tests cost $100 – $500. microBIOMETER® takes 20 minutes at an average of $10/test.
* Soil microbes quickly die when removed from the soil. microBIOMETER® reveals the microbial biomass of your soil as it exists. Lab tests use dried soil and we have demonstrated that 80% of microbes die upon drying.
* The low cost and simplicity of microBIOMETER® means you can use it to monitor what is happening in time to make necessary corrections.
* microBIOMETER® can tell you if you are increasing your soil organic carbon. For instance, an increase in microbial biomass of 100 ug MBC/g per acre of agricultural land is equal to an elephant’s weight in microbial biomass, which is about 400 lbs of microbial carbon or >1450 lbs of CO2 equivalents. This can be accomplished by switching from heavy chemical fertilizer use to regenerative practices.