In reality, we know very little about all the interactions between the lifeforms and other components in our soil. The bacteria, fungi, nematodes, you name it, and the nutrients, minerals, etc.  Each of nature’s organisms must play its part in the soil cycle to achieve the transformation from raw nutrients to plant-available forms that support our crops. 

Your Soil Must Have Oxygen

Earthworms are the best indicator that you’ve got good soil health, as the earthworm is at the end of the food chain. Earthworm poop is one of the greatest things for the soil, as the earthworm has, in effect, consumed everything else along the food chain in one way or another. But there’s one critical thing that earthworms and all soil life need: oxygen. I talk a lot with other farmers about what is going to “tip our soil over” first: lack of food, lack of water, or lack of oxygen? 

We all know that we could survive a short while without water and a little longer without food. But a lack of oxygen? That would kill us in a couple of minutes. And it’s no different for our soils. Think about what happens in a flooded field. Or think about what happens when you have a lot of soil compaction going on. There’s no room for oxygen in the soil. 

The aerobic soil microbes have to have oxygen. And that’s why it’s critical that we address soil health by addressing the oxygen levels in our soils. This is why I designed my own CarbonWorks products specifically to deliver molecular oxygen. I wanted to enhance the aerobic bacteria in the soil so they can do a better job of processing nutrients for the plants. 

Anhydrous Ammonia Brings Serious Soil Side Effects 

As I mentioned earlier, most of the man-made fertilizers started appearing around World War II. Anhydrous ammonia actually had its start earlier, around World War I, with the Haber-Bosch process. The problem is, anhydrous ammonia has always been dangerous, not only for us, but for the soil biology as well. Anhydrous kills all the biology it touches as far as two feet away from where the tool bar has injected the nitrogen. 

I’ve never been around anhydrous. So one day I looked the word up in Webster’s dictionary. I didn’t know what it meant; I had no idea. Anhydrous means “without water.” The way anhydrous kills biology in the soil is through dehydration. It literally draws all the water and oxygen to itself and basically suffocates and/or dehydrates the biology in the soil. Of course, the biology does come back in time. Now, the co-op isn’t going to tell its customers that “anhydrous kills everything it touches.” It’s just about the cheapest form of nitrogen, and for many agronomy programs, that’s its utility. 

However, there’s never a free (or cheap) ride. There are potential side effects to anything and everything. There are positive attributes to using anhydrous, but there are also the negatives. It may be the cheapest form of nitrogen for sale at the co-op, but it seriously harms your soil health, and farmers don’t seem to be as familiar with this aspect. 

Once Upon a Time with Ammonia: Building Runways

During World War II the United States armed forces used a form of ammonia to build runways on remote Pacific islands by hardening the dirt surface into something that resembled concrete. How does it do that? Well, guess what? It kills all the soil biology. By living and breathing and moving and doing whatever it is they do in the soil, the biology in the soil create porosity and soil structure.

And that’s the problem. The negative effect of this compaction is that you can’t get oxygen into the soil. You can’t get water in. You can have all the nutrients in the world in the soil, but without oxygen, they’re of no use. If no one’s home (the biology is dead), it’s not going to do any good to keep adding fertility to the soil. You have to have a balance. And that’s what I’ve been talking about during my entire career; we have to find the best balance we can in our soils between the biology, the nutrients, the water, the oxygen—all of the above. 

Plants Need More than N, P & K

Over time, I learned why adding more and more fertilizers to the soil would degrade my soil health—because I’m basically adding more salt. You need salt among the other minerals in the soil, but you only need so much. If we take a tissue sample from a plant and we send it to the lab and have it analyzed, no more than ten percent of the plant tissue will be made of so-called nutrients. And most farmers don’t realize that. They’re just like our bodies: plants are made up of water and carbon. 

Since World War II, we’ve been led down this path by commercial agriculture of predominantly addressing N, P, and K. To me, we’ve been putting too much emphasis on only ten percent of our plants. This focus mostly benefited the big chemical fertilizer companies; it certainly didn’t benefit us growers in the long run. 

What is ‘Soil Fertility’?

You could talk about soil fertility as an acceptable range of organic matter in our soils. We would all love to have what you guys have in Minnesota, Iowa, and Illinois—that rich, black dirt, which is very fertile ground. When you’re in the range of three to five percent organic matter, that’s a blessing and a luxury. Down here in Florida, I have less than one half of one percent. I have a CEC (cation exchange capacity) of three. In the Midwest, on soils that I’ve worked with, I’ve seen CECs between twelve and twenty-five. 

From the FCLG: According to Michigan State University, “CEC indicates how well soil holds on to anything applied to it (emphasis on anything) and how difficult it is for plants to take it away. Soil particles are negatively charged and attract positively charged molecules. These molecules can be nutrients, water, herbicides and other soil amendments. A soil particle’s ability to react with these molecules is called the cation exchange capacity. If the CEC number is low, not many molecules are able to bind (react) to the particle surface. If the number is high, a larger number of molecules can bind to the particle’s surface.”

One way to think about CEC is that for every one CEC, the soil can hold ten units of nitrogen. It’s basically linked to the structure of your soil and measures how your soil can hold nutrients. The Earth has predominantly a negative charge. We know that for something to be attracted to and hold to Earth, it would have to have a positive charge. 

Balance Inputs to Boost Yields 

Most forms of nitrogen wind up with a negative charge when they become plant available in the soil. And negative charges repel the Earth. And that’s why nitrates leach. But we want that nitrogen fertilizer we bought from the co-op to hang around. We want the biology and then the plant to utilize that nitrogen and build tissue. We want to have a lot of leaves. So we grow the plants, in what people in the corn belt refer to as the V stage. But then we need the plants to move out of the vegetative stage and push into the reproductive stage. This is the stage where we’re building sugar and we’re pushing that sugar into what hopefully will be our yields. 

But the bottom line is that at least half of the photosynthetic sugar made in the plant goes down to the root system to feed the biology in the soil. All farmers know the importance of photosynthesis to the plant, but below ground is crucial, too. Half of the sugars are feeding the workers in the soil. And half of the sugar is being driven, hopefully, into our yield to form a crop we want to sell, whether it’s kernels of corn or soybeans in a pod. 

This is where we need the right balance of all the nutrients and inputs and everything else so we can maximize our yields. You need the right amount of inputs to get the right amount of outputs. 

Too Much of One Nutrient is Too Much

Does it make sense to look at the soil as a medium to hold nutrients? That’s somewhat accurate, but not the whole picture, as I’ve been saying. You need to have a certain level of nutrients available to your plants. The co-ops and a lot of other people have had us convinced that we need to be storing up massive amounts of these nutrients in that soil bank. Now, the reality is—it’s the soil biology that is the determining factor in whether those nutrients are released or not. The biology has to break down those nutrients and free them up for uptake by the plants’ root systems. 

In days gone by—ten, twenty, fifty years ago—we were told to “just add more N, P, and K and watch our yields increase. And they did . . . to a point. But there’s always a point of diminishing returns. When fertilizer was cheap, many farmers pushed that envelope. Like I’ve said, soil health is all about balance, so too much of a good thing is just too much. And that can go for anything. You can have too much water. Too much oxygen. Too much carbon. Too much organic matter, manure, fertilizer, or too much herbicide. We could go on and on. 

I can’t stress this enough: balance is the key word. Yes, we need nutrients in our soil, but we also want nutrient availability. For example, we know today that growers should make multiple applications of nitrogen. You can’t just apply it as one and done with anhydrous—you won’t have the best corn crop that you could have had. If you split applications of that nitrogen and also not put it all down in anhydrous ammonia form, you can do a better job. You could put down some urea, for example. 

I want to share this information that I have obtained over fifteen years now in the Midwest, working with agronomists and farmers all over the corn belt. They back up what I’ve just said; split applications of nitrogen, done at the right time, will do a better job and not be as detrimental to your soil health. 

Maintain A Healthy Balance in Your Soil

Remember: too much of a good thing is simply too much. And, while we’ve been taught to keep nutrient levels high in our soils, we also have to think about the plant availability of those nutrients at any given time. And you also have to take steps to ensure that your soils are rich in oxygen, because without oxygen, the soil biology that your plants depend on (and your plants themselves) will quickly be in trouble. So, as we continue this article series, we’re going to focus on carbon and its role in protecting your soil health, and also introduce you to some of the products (and marketing claims) in the market today.