We sat down with Andy Dardini, owner of Physagro, to talk about biologicals—a broad category of products formulated to deliver or support microbiological life. In the process, we learned that we have a lot to learn about what happens in our soils on the microscopic level. Before we cover the products themselves, we asked Andy to share some ground-level information about our soil biology and the vital functions it provides to us as farmers.

Soil Biology Feeds Your Farm

The biggest function of soil biology is nutrient conversion. The biology is largely responsible for getting minerals that are in the soil into available forms for the plants. Without them, it’s very difficult for plants to actually use and extract minerals from the soil because the nutrients are in the wrong form. 

Beyond that, they’re doing a lot of things behind the scenes that are hard to quantify. For example, disease prevention. Soil biology naturally maintains a healthy balance of microbes in the soil, functioning like a soil immune system. And your soil biology also breaks down residue and they create organic matter. So they obviously play an important role in creating a healthy soil structure. But really, the two biggest jobs for soil biology from a farmer’s point of view is nutrient conversion and disease prevention. 

A Little Understood Ecosystem

It’s important to remember that we’re not just talking about one organism performing one function and another organism performing another function; all of them work together. Bacteria, fungi, nematodes, earthworms—the entire range of life in the soil. They also serve as a food source for each other: bacteria are a food source for fungi and the fungi are food for the nematodes and so on. 

And you can’t just have a bunch of one or another; balance is essential. This is an area that I feel has been very under investigated. There’s not a ton of information out there on exactly how the entire system works. When I was studying for my agronomy degree, there was only one semester of soil health required and there was very little discussion about it. The soil reference materials you can find are often from the 1970s and 1980s, at least the latest batch of them. 

Learning about our soil has definitely taken a back seat as we’ve gone heavier and heavier into synthetic fertilizers and some of the other practices we employ now. Part of the issue is the laser focus on yield—those bushel numbers. And the other part is that we simply have fewer people in agriculture today.  I think the average farm size today is close to one thousand acres. Thirty years ago, that would have been a few hundred acres. 

Threats to Soil Biology Today

Unfortunately, a lot of the threats to our soil biology stem from the mainstream farming practices that we depend on today: excessive tillage, compaction, and synthetic, inorganic chemicals. These include herbicides, pesticides, fertilizers and even the seed treatments we use. All of these are counterproductive to creating a good biological growth zone. 

Synthetic fertilizers, for example, are incredibly salty as a result of their manufacturing processes. So, even if a fertilizer is in an organic form, such as urea, it becomes very salty and concentrated when it’s processed. This makes it difficult for soil microbes to break it down in a timely manner. It’s like one of us eating at a buffet; there’s so much food, but you can only eat so much in one visit. And if we do try to eat everything, we’re going to damage ourselves. In many instances, we have too much of a nutrient or a nutrient in the wrong form at one time.

Synthetic Fertilizers: More does Not Always Mean Better

There are a couple reasons we don’t see traditional synthetic fertilizers continue to increase in effectiveness: a decline in soil biology and the negative side effects of the fertilizers themselves. We have less active microbiological activity in the soils than we have had in the past. So, we have fewer workers doing the work. And because of this, we’re constantly trying to introduce more of the synthetics to try and put down more nutrition to compensate for the lack of microbiological activity. 

In some ways, this cycle is similar to the problem with antibiotic resistance in medicine; when you keep doing the same thing over and over—and too much of it—eventually you lose effectiveness. Since our synthetic fertilizers are so salty and so aggressive on the bugs, we’re inadvertently reducing our microbiology populations every time we increase our synthetic fertilizer use. And so we’ve come to a point where there’s a large percentage of our microbiology that’s inactive and we’re just continuing the cycle—trying to add more synthetics to compensate for the fact that there aren’t as many workers to actually make the nutrients plant-available. 

Less Nutrients Available When the Food Chain is Broken

Some species of microbiology are more resistant to the chemicals than others, which is great. Those of us in the biological world can then work to introduce necessary bugs that are also among those resistant to the effects of our synthetic fertilizers. But there’s also a scary side to this: You may have one or two types of bugs that are fairly resistant, but there’s sometimes several species in the chain of life that need to be active for nutrient conversion to occur. 

Take nitrogen conversion, for example. If we’re trying to make nitrogen available and get it into our plants, it takes at least two families of microbes to make that conversion happen. You can have one species that is resistant to synthetics and active in your soil, so you’ll get part of the conversion. And then the process will stop, because a second family has been knocked out of commission. So this is always a learning process; we have to investigate what’s taking place in the soil, find out which of the workers are most vulnerable, and then focus our efforts on rehabilitating those. It doesn’t do a lot of good to keep adding soil biology that is already tolerant of the synthetic chemicals; as I’ve said, nutrient conversion often requires an entire chain of species.

Microbiology Uses Dormancy as a Protection Mechanism

Microbes will go dormant to protect themselves when conditions are threatening. When it’s 97 degrees outside, my natural reaction is to hang out in the air conditioning until it cools off. The same thing happens in the microbiological world. If there is no food available or conditions aren’t conducive to being active, the microbiology slows down—they go dormant. As I’ve mentioned, with our current farming practices, we’ve increased the number of dormant bugs.  

Microbes are 85% to 95% water. It’s super hard for them to function in a super-salty environment, which we create with synthetic fertilizers. So, because of this, we have a much larger dormant population than we should. But this also gives us an opportunity. We can develop products that deliver energy in the form of sugar, which can help condition the soil to try and reinoculate and establish new colonies and break the dormancy of the ones that are already there. 

Microbiological Diversity Protects Soil Health and Our Health

There have been some articles out of the Mayo Clinic and Cleveland Clinic highlighting the importance of microbiological diversity in the human gut. They’ve found that the population and health of the microbes in our gut largely determine our health and our immune functions. What they’re finding is that the people who are on the fewest medications and have the fewest symptoms of illness are the people who have the most diverse population of microbes in their gut. 

We’re experiencing similar parallels in our soils. In areas where we have low microbiology populations or areas where we have very active singular strains but low diversity, we see a lot of disease and nutrient deficiencies. On the flip side, when we use cover crops and other strategies to enhance our soil health, we don’t see a lot of disease and we even see better yields. Based on the research I did in college, this correlation didn’t come as a surprise to me. 

It was reassuring to see studies start appearing that made the link between gut health and the health of our environment. Why do people experience poor gut health? Well, part of the equation is that we’re consuming foods that contain pesticides or that have been genetically modified and still have those biological markers and carriers in them. They’re highly inflammatory, and all this is detrimental to our microbiome’s health. 

Keeping Pests in Their Place

Our soil biology’s second most important function after nutrient conversion is pest and disease management. Think about the state troopers at a large concert; people in the crowd are a lot less likely to do something stupid if you have a deterrent in place. Think about our own gut for a minute; at any given time, we have one to two million strains of e coli in our gut. The reason these colonies don’t cause problems is because we have enough of the good bugs in there to deter it—to keep the e coli at bay. If you do something to cause the proportions to get out of balance, then you have problems.

It’s the same concept underground. There is actually a ninety-eight percent overlap between microorganisms in our gut and microorganisms in our soil. If you were to pull a microbe from your gut, there would be almost a one-hundred-percent chance that you would also find it in the soil. This is why some people strongly believe that it’s very beneficial to eat seasonally and locally whenever possible. Any time we’re knocking out a portion of the good bugs with synthetic chemicals, we’re increasing the likelihood of pests and disease taking hold. And then you have to add more chemicals to control the pests and it becomes a never ending cycle. 

Healthy Soil Benefits our Farms and our Bodies

I hope I’ve conveyed the importance of a healthy microbiome in our soils. The fact that we have crops that are not as nutrient dense or not as healthy relates to each of us in the sense that we no longer have food that is as nutrient dense as it was years ago. In other words, your soil health isn’t just a farming concern; soil health should be a priority because our own health is directly tied to it.