The web of life within our soils

What is soil health? When I think of soil health the first thing that comes to my mind is Wendell Berry’s quote from his book The Unsettling of America: Culture and Agriculture, “The soil is the great connector of lives, the source and destination of all. It is the healer and restorer and resurrector, by which disease passes into health, age into youth, death into life. Without proper care for it we can have no community, because without proper care for it we can have no life.”

There are few things that truly awaken my senses and one of them is a handful of healthy soil. Sometimes we simply don’t need a soil test to know if the soil we are holding in our hand is healthy. The soil will be a rich, brown color and smell earthy. This usually means the soil has good organic matter and a balance of nutrients. The earthiness smell comes from good, active microbial life. It should crumble easily from your hand. This means the soil has good texture. There is space for air and water to be stored. I take most of our soil samples with a soil probe or sharp shooter shovel. The tool should be easy to work down into the soil. If it isn’t then there are most likely underlying compaction issues. We deal with compaction issues a lot in our clay/loam type soils prevalent throughout South Texas. Unfortunately most of us don’t get to experience the kind of rich soil I just described. For most of us in agriculture this soil has all but disappeared. Someone chasing every last cent out of the ground took it all away. Most of us are dealing with sub-soil layers that were previously covered with rich earth. During the last ice age flowing ice stripped away whatever soil had been there and left glacial till. Upon this glacial till soil was re-built for thousands of years. That is until overgrazing and industrial agriculture came in recent history and began to deplete the soil. My point is that most of us are dealing with sub-soil layers that were previously covered with rich earth.

We have a letter written by my family from 1846 when they established the homestead here at what is now Parker Creek Ranch. The letter was written to our family in Alsace describing the landscape. They briefly describe a lush, grassy valley with two flowing creeks. Though I am sure there were a few trees they didn’t describe them in the letter. Come visit our ranch now and most of it is covered in bull mesquites and brush. A few things stand out to me in these few short words they used to describe the ranch. To start with “two flowing creeks.” This means that perhaps there was a functional water cycle at that time. The Spanish had already been in the area for a few hundred years, but this region was mostly inhabited at that time by Native Americans. A “lush, grassy valley” hardly exists anymore. What grass is here in our valley was planted over the past few decades after the land had been cleared of mesquites and brush. Without knowing any better at the time we literally changed the ground level vegetative community that had been present for hundreds if not thousands of years in less than a century. Almost all of these planted grasses are exotics from Africa or Asia. Most of the soil on our property is no longer that dark, deep top soil that was once present. It is an eroded, heavy clay sub-soil with nicely rounded flint stones (glacial till) left over from the last ice age.

For over ten years our primary focus at Parker Creek Ranch has been to restore the soil. We have been testing our soil chemistry at Parker Creek Ranch for almost a decade. Mandy and I with our biology background had the foresight in our early years to test the soil so that we would have baseline data in the future. Our initial soil chemistry work was done at Texas Plant and Soil Labs in Edinburg, TX. You can check out those early tests and later ones by following this link. These earlier tests gave us a really good idea of what was going on below the surface and it’s effects on our plant communities. We were able to gain some insight into earlier problems that we were seeing. Little did we realize that the microbes were helping us correct those problems all along.

My wife, Mandy and I did a consultation with Earthfort, a soil laboratory located in Oregon a few years ago. We had always known that life below the soil was important, but this one conversation was like a light bulb clicking on in my brain. You can read all of the books and listen to all of the speakers, but until someone tells you something so clear and concise you might not ever understand it. The reason for the consultation was to interpret the microbiology report we had just received from the lab. Looking it over by ourselves was a bit daunting to say the least. There are all of these words and numbers next to them that mean nothing to the untrained farmer. This one consultation was a real affirmation for what we have been thinking about for years. We have been doing all of the right things on the surface of the soil, but neglected to think about what was going on below the surface. Little did we realize that this is where are all of the “action” is taking place. We know very little about life below the surface of the soil. What is becoming apparent is that it’s the most important component to soil health. Without a healthy microbial community the soil will remain broken. These microbes make it possible for nutrients to cycle, for water to infiltrate, for plants to capture energy and so much more.

The information below is sourced from Dr. Elaine Ingham’s The Soil Biology Primer. I am by no means a soil scientist or an expert on soil microbiology. My goal is to provide you with a basic understanding on the most fundamental level.

Life below the surface of the soil is so interesting and complex.Imagine it as a microscopic ecosystem with plants, predators and prey relationships. All of them intertwined and relying upon one another. It starts with the fungi and bacteria, which is the beginning of the soil food web. They support other soil organisms and the functions of a healthy soil. These soil fungi perform services related to water dynamics, nutrient cycling and disease suppression. Along with the bacteria, fungi are important as decomposers in the soil food web. They convert hard-to-digest organic material into forms that other organisms can use. Imagine a network of fungal hypae (long strands of fungi) like an underground highway below our feet. These fungal hypae physically bind soil particles together, helping to increase water infiltration and soil water holding capacity.

Soil bacteria are tiny, single-celled organisms that make up huge populations of the soils microbiology. A teaspoon of good, healthy soil contains 100 million to 1 billion bacteria. Most of these bacteria are decomposers that consume simple carbon compounds, such as plant litter. Bacteria are especially important in retaining nutrients in their cells, thus preventing the loss of nutrients from the rooting zone. One particular group of bacteria called the mutualists form partnerships with plants. The most well-known of these is nitrogen fixing bacteria that we often see applied as a seed coating for legumes.

Next on the microbiology report is the protozoa. These are small, single-celled animals that feed primarily on bacteria, but also eat other protozoa, soluble organic matter and sometimes fungi. As these protozoa eat bacteria they release excess nitrogen that can be used by plants and other members of the soil food web. Protozoans are typically classified into three groups: flagellates, amoebae and ciliates. Protozoans primary role in the soil food web is to mineralize nutrients, making them available to be used by plants and other soil organisms. Another important role that protozoa play is regulating bacteria populations. Imagine the Yellowstone wolf regulating the elk and bison herds and it changes the ecosystem. As the protozoa consume bacteria, it actually stimulates growth of the bacterial population. This action by the protozoa increase decomposition rates and soil aggregation. Protozoa need bacteria to eat and water so that they can move throughout the soil. Thus moisture plays a significant role in determining which types of protozoa will be present and active.

The last part of the microbiology report is the soil nematodes. Nematodes by definition are non-segmented worms. There are a few nematode species that get a lot of attention for the role in the soil food web, and the remainder of nematodes we know very little about. Some nematodes eat fungi, others bacteria and furthermore others eat other nematodes and protozoa. Nematodes play a key role in mineralizing nutrients and turning them to plant-available forms.

The web of life below the soil continues to the micro-arthropods, soil insects and so on. It is one of the most complicated systems on Earth that science knows very little about. Science has just scratched the surface in regards to it’s knowledge about life below the surface of the soil. I can remember ten years ago when very few labs in the States even offered microbial analysis. Our knowledge of the soil was simply based on the chemical reports. Most soil scientists will agree that its the microbes that really matter. Of course, there are certain chemical aspects to the soil that make a healthy microbial population possible, for example organic matter. But when it comes to the major nutrients and the micronutrients the microbes play a very significant role in making them plant-available. You can read about the five principles of soil health in a blog I wrote a few weeks ago. If you follow these principles it will restore health to your soil.

Why does all of this matter? If your a consumer, the health of the soil directly effects your own health. You literally are what you eat. Your skin and organs shed cells and replace them constantly. Where do you think the nutrients come from to make all of this possible? If your a farmer, the health of the soil affects your lands productivity and ultimately your bottom line (profitability). The microbes can’t achieve this all on their own. As ranchers we have to help our microscopic livestock. Good management and livestock are a key element to the equation of regenerating degraded soils.

I hope this article has been a good primer to get you interested in thinking about life below the surface of the soil. If you want to learn more I highly recommend these three books to get your started: For the Love of Soil by Nicole Masters, Dirt to Soil by Gabe Brown and the Hidden Half of Nature by David Montgomery and Anne Bikle.

Thanks for reading,

Travis Krause, CEO & Founder of Grazing Lands