Community gardening with microBIOMETER®

Informal science education is a key for community engagement and healthy gardening. Community gardening  brings numerous benefits such as fresh produce, therapy, physical exercise, reduction in grocery bills, improvement of mood among many others.

“Last weekend I had the privilege to teach community gardeners on the importance of soil testing side by side with my very first student at NYBG Adult Education program (class 2015). Dr. Joan Basile is a clinical psychologist who has developed her own horticulture therapy program incorporating soil knowledge brining therapy & soil science & gardening together.” – Dr. Anna Paltseva,  soil_expert.

“While the microBIOMETER® results showed there is room for improvement, the result from last year’s beds also proved that composting and mulching practices are paying off in increased soil life. This means that sandy soil will gradually be able to hold nutrients better and better!” – Dr. Basile

microBIOMETER® in University of Michigan Research Study

Joshua Mikesell utilized microBIOMETER® in a University of Michigan Intern Student Program last fall for his 501(c)3 compost business Happy Coast.  The goal of his compost business is to seek out organic waste products and develop ways to reduce and recycle these materials. In preparation for the study, Joshua created multiple controlled scenarios to test biomass in certain situations and in several types of compost.

For the project, they sorted through food waste obtained from local businesses and developed a process and ingredient list to produce their own organic fertilizer. microBIOMETER® was used to perform the initial tests. Then after their pellet applications was used again to determine effectiveness.

The University of Michigan was so impressed with Joshua’s study they now want to send him as many students as possible to continue this work.

Click here to read the entire report as well as view all the microBIOMETER® data collected.

Soil Carbon Q & A with Dr. Judy

soil carbon

We recently received the following questions from one of our customers and below are the responses from Dr. Fitzpatrick.

Part of my research is surrounding the soil organic carbon results we attained from microBIOMETER®, and I am wondering if someone from your team could provide more information on what this means relative to total organic carbon (TOC) in a sample and if they are comparable?

The literature shows a strong correlation between available organic carbon and microbial biomass carbon (MBC). Since your compost is not soil, the available organic carbon in your sample would be TOC and would correlate. MBC by microBIOMETER® is even better than that: a big number tells you that you have carbon and all the nutrients needed by microbes and plants.

Since MBC has correlations to TOC is there a formula or percentage to convert MBC to TOC? Or approximately how much MBC makes up a TOC number?

There is no formula to correlate TOC with MBC. TOC includes carbon that we consider stored as well as carbon that is easily available to microbes. Increasing easily available carbon for example by applying compost will increase microbes and eventually increase TOC, but as microbes rarely exceed 1% of TOC, it would have little effect on TOC short term. In long term stable systems we see a correlation but the correlation is not the same for example in forest as in agriculture as the capacity to store TOC is different soils under different conditions. In studying the effect of long term (40 years) different management systems at U. of TN on MBC and TOC, MBC by microBIOMETER® correlated with the TOC demonstrating the effectiveness of sustainable practice on increasing TOC and the positive correlation with MBC levels.

Does a high MBC usually mean a higher F:B ratio? And if so, could we draw any conclusions about carbon sequestration capabilities from that?

Generally as the MBC increases there is an increase in fungi. The soil food web is a balanced community. Some communities are more fungal dominated some less, but similar communities tend to have the same F:B ratio. It is generally believed that fungi, especially mycorrhizal fungi, contribute more to carbon sequestration than bacteria. This may be because glomalin is carbon rich and tends to sequester.

To further my understanding of soil/compost mixtures. I performed two microBIOMETER® tests. One test was on “active compost” which is compost in a medium stage of decomposition, and generates some CO2 and another one “finished compost” which is cured, ready for usage, and low CO2 production. However, I found that they had similar amounts of MBC and F:B ratio. Is this normal?

A study with microBIOMETER® at University showed a higher F:B in finished compost. The higher respiration/MBC indicates that your unfinished compost is still being digested — working microbes make more CO2. Holding MBC stable in your finished product is good.

 

New York Times features Prolific Earth Sciences advisor/board member

Jeff Lowenfels

Jeff Lowenfels, a valued advisor and member of our Board, was recently featured in the New York Times Sunday Magazine article, He Wrote a gardening column: He ended up documenting climate change.

For 45 years Jeff has written a gardening column for the Anchorage Daily News and over this time has helped adapt Alaskan growers to their much longer growing season. And in doing so has become a documenter of climate change.

Jeff joined  Prolific Earth Sciences because he knew the only way to wean agriculture off synthetic fertilizers was to trust the microbes to deliver nutrients to plants. Jeff is the well-known author of the all-time best selling gardening book, Teaming with Microbes, as well as Teaming with Fungi, Teaming with Nutrients and DIY Cannabis all very readable, informative and available on Amazon.

Soil testing update from Brazil

Chiappetta Agricultural Company

We were excited to hear from our long-time customer Marcelo Chiappetta of  Chiappetta Agricultural Company on how his microBIOMETER® testing has been progressing. Below is what he shared with us.

“Here in southern Brazil the past 5 years we’ve been working with biological agriculture and changing the way we see and manage our farm; more and more like an agricultural organism. Taking care of microorganisms, plants, animals and humans and focusing on producing high quality grains.

Fungal and bacterial ratio is fundamental to know how our soil is related to what crop we grow. And now, after starting to brew compost tea and using compost extract, microBIOMETER® is helping us measure and understand the right recipe of carbon and nitrogen related to the amount of fungi that we want to build in our composts before adding to the soil. We see that good microbial biomass along with organic matter is excellent for our soils.

In practical terms, we see biological flowering in crop fields and this is the proof that we are doing a great job with nature. Our soil is our bioreactor, and we need to feed it with the right nutrients. The Brazilian biome is rich on biodiversity and as farmers and soil guardians we have a responsibility to bring life back to our farm again in a sustainable way of producing food.”

Click here to read more on Marcelo’s soil testing.

The Role Microbes Play in Increasing Soil Fertility

soil fertility

The microbial population or microbial biomass (MB) reflects soil fertility. For over 2 million years, plants and soil microbes have worked together to create what we call fertile “soil”.

How do they work together? The plant supplies the microbes with carbon rich food. The microbes then mine the soil for the required minerals. Microbes can actually manufacture nitrogen and antibiotics that protect the plant from pathogens in return creating carbon stores that build soil structure and sequester carbon.

Like all good partners, what is good for one is good for the other, i.e., a healthy MB predicts a healthy plant. Therefore, supplying NPK directly to plants disrupts the plant microbe relationship – plants no longer feed the microbes and the MB decreases accordingly. Soils with low MB suffer from erosion, compaction, and poor structure. Sadly, this is how we have lost 50% of the earth’s soil.

Soil microbes, like all living things, need food. They need to be fed carbon and nitrogen from plants or organic matter so they can mine the minerals, P, K, Mg, Cu S etc. from the soil. If there is not enough of any nutrient, including the minerals that should be in the soil, it negatively affects the number of microbes; just as humans do not thrive when we are deficient in a critical nutrient.

Oxygen, water, and an agreeable pH and temperature are also important for soil microbes. Compacted soil is low in oxygen and microbial biomass. As soil dries, microbes die or become dormant. MB is much lower in low and high pH soils than in those that are in the neutral range. This is because most enzymes work best at neutral pH and all metabolism is enzyme dependent. MB also contracts during intense cold and heat. Plant roots require these same conditions

Microbes also need shelter to survive. Soil aggregates provide small cubbyholes that accommodate oxygen and water. It is in these areas where microbes attach themselves to be protected from predators. These predators are larger than they are; think of how little fish hide in coral. Not only are soil aggregates homes for microbes, they are homes built by microbes. The capsular material that microbes secrete to attach themselves to soil particles is long lasting. It binds the soil particles, therefore, creating aggregates that build soil structure and prevent erosion. These aggregates provide the water, oxygen and wiggle room needed by plant roots.

Furthermore, soil microbes build up carbon in the soil by producing humic matter. When microbes die, their bodies become stored carbon. This is good for microbes in the way that a savings account is good us. It is important for the soil as well because the humic matter increases soil structure. This allows more oxygen and water storage. It is also a resource that microbes can take a loan from before harvest when plant material is not being released to microbes. For too long we have relied on microbes borrowing from this humic carbon source and have released ½ of the soils stored carbon to the air as carbon dioxide. This has contributed to climate change and loss of 50% of earth’s soil. Microbes have always worked well with plants to create soil and they can help us restore exhausted soils back to fertility.

Microbial Biomass vs. Microbial Respiration

What is the difference between microbial biomass (MB) and microbial respiration rate (RR) ?

Both parameters are used to assess soil microbial health. The respiration assay measures the amount of carbon dioxide produced by the microbes in a given weight of soil. The soil is dried and then rewetted and put in an airtight jar that allows measurement of the amount of CO2 produced over 24 hours. The CO2 is produced by the activity of the microbes in the rewetted soil. Between 20% and 70% of the microbes die during drying but their dead bodies often provide nutrition for the survivors to use and regrow the population to its original level.

Respiration reflects the regrowing work that is being done. The respiration level is often mistakenly believed to predict microbial biomass (MB), but it does not. Microbes in a low pH or toxic soil have to work harder, therefore, their respiration rate is higher, just as your respiration rate in the gym is higher than when you are watching TV. Outside of the U.S. the respiration rate (RR) is only considered in relation to MB and this q-value RR/MB is used to determine the level of stress in a soil. If RR is high for the MB, the soil is in trouble.

MB, as measured by microBIOMETER®, correlates with chloroform fumigation—always and microscopic evaluation of soil. It is an excellent predictor of soil health because the size of the microbial population correlates with the nutrition available in the soil. If the soil is deficient in carbon, nitrogen, phosphorus or any other mineral, or contains toxins, MB will be low. In fact, MB is low in any soil that is compacted, has a low pH or is overly dry, because microbes need oxygen and moisture and the correct pH for enzymatic activity.

In nature, the plant uses 30% of its food production to feed a microbial population that will mine the soil for the N, P, K, S etc. that it needs. Interestingly MB is low in soil treated with high levels of mineral fertilizers; researchers have shown that the stimulus for the plant to grow a microbial population is its need for nitrogen and phosphorus. If these are artificially supplied the plant is not stimulated to feed the microbes that usually provide these nutrients to the plant. And since the microbes are at least half of the immune system of the plant, you now need lots of pesticides to protect the plant.

Simple ways to increase the microbial biomass in your soil

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.

  • Pesticides

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.

  • Fungicides

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. 

  • Tilling

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.

  • Composting

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. 

  • Compost Teas

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.

  • Optimize soil moisture, pH, and temperature

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.

 

Soil Health Improvement Tracking

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.

What is a good level of soil microbial biomass?

Understanding Soil Organic Matter and its impact on soil health and microbial biomass.

We are often asked what is a good level of microbial biomass (MB). There is no one answer. The level of MB you can reach is dependent on soil organic matter (SOM.) Soil organic carbon (SOC) is a large part of soil organic matter but SOM is a mixture of Carbon (C), Nitrogen (N), Phosphorus (P), Sulfur (S) and all the other minerals that microbes and plants need.

There are 2 types of SOM: Stable SOM, often referred to as humic matter; and Fresh SOM. Fresh SOM is composed of SOM material recently released from Stable SOM and any fertilizers, amendments or litter. You can compensate for low stable SOM by providing lots of fresh SOM. The key to the efficacy of fresh SOM is that it needs to be nutrient balanced*, i.e. it needs the correct balance of C,N,P, and S. That is where understanding soil chemistry and using the right additives comes in.

Think of SOM as your credit reserve. In spring, the plant starts to grow and puts out exudates that stimulate the microbes to multiply. But these multiplying microbes need more than the sugars that the plant supplies, they need the N, P, S and micro nutrients that are in SOM.

Agronomists often cultivate soil for intensive organic agriculture and those soils contain lots of fresh organic matter. The microbial biomass of these mixtures can read as high as 2000 ug MBC/gram of dry soil. As the microbes and plants in this rich soil die, they become fresh SOM. The amount of stable SOM that soil can store depends to a large degree on the type of soil because storage requires mineral surfaces for attachment and aggregates for protection. If your soil is inherently poor at storing SOM, you will need to rely on fresh SOM to feed your microbes and plants.

We highly recommend that you read the review referenced below to better understand SOM.

Coonan, E.C., Kirkby, C.A., Kirkegaard, J.A. et al. Microorganisms and nutrient stoichiometry as mediators of soil organic matter dynamics. Nutr Cycl Agroecosyst 117, 273–298 (2020). https://doi.org/10.1007/s10705-020-10076-8