The Six Basic Principles of Soil Health: An Explainer

This article was adapted from Dakota Resource Council’s website.

Soil health is a journey, not a destination. This roadmap will help you understand where you’re going.

In the world of regenerative and sustainable agriculture, there are many practices and buzzwords. It can be hard to separate ideas that are actually regenerative from greenwashed corporate speak. Regenerative health is flexible. There is no “one true method” of gaining perfect soil, especially if you have land that has been affected by humans in one way or another. With all the information that is available Dakota Resource Council created this guide to the six basic principles of soil health and what they mean. This is by no means a deep dive into regenerating your soil, but more of an introduction to the six basic principles of maintaining healthy soil. They also included information about how you can track your soil’s health.

Principle 1: Context

The first and perhaps the most important aspect of soil health is knowing what type of natural conditions your soil is supposed to be in. This doesn’t mean what the soil looked like when you were growing up on your farm 40-50 years ago. The question you want to ask yourself is what would this soil look like in a natural state with minimal human contact? In many cases, you will have to understand the ecology of the area before humans permanently settled it or used it in a way to harvest a particular resource. What plants, animals, and natural events happened on your soil? The Midwest and North Dakota was once a large grassland with a herd of around 75 million buffalo migrating the northern plains with large populations of elk, deer, and prong horned antelope following the herd in a very similar way we see the wildebeests, zebra, antelope, and gazelles roaming the African savannah. Tall grass kept the soil from blowing, and upland birds lived in the grass and wetlands in the hundreds of millions. Thunderstorms, tornados, and brush fires were common on the prairie and long cold winters were common with deep snow.

Knowing your context is important because it allows you to set realistic goals for your garden, your cattle operation, or your fields.  Knowing how much water you need or can survive on and planting the right crops that can grow in your environment makes sure that you have a better chance at a successful harvest and doesn’t have you scrambling to find water for your livestock because you put too many on your land.

Principle 2: Minimize Soil Disturbance

Soil works best when digging or tilling your soil as little as possible.  North Dakota loses around 5-7 tons of topsoil per acre per year.  One ton of soil on an acre is only as thick as a piece of paper. It’s not easy to see immediately. Microbes and other living things need the soil to stay intact as much as possible because they live in the pore space between the clay and organic matter that the soil is made of.  Water and air trapped in the soil goes away when soil is tilled. Keeping your soil intact will decrease the amount of erosion or leaching that happens to your soil each year.

Principle 3: Living Root

At the same time, it is important that you have a living root in your soil whenever possible. The Living root creates the space where bacteria, insects, and fungus that make up your organic matter in the soil live. Roots also connect the soil with small fibers that keep it firmly locked in place. Roots can keep a crust from forming on the soil and are essential for absorbing water when it rains.  With a well-developed root system, your soil will stay firm to walk on and more resistant to seasonal flooding. 

Keeping a living root in the soil is a difficult task when your operation requires harvesting a crop but there are some methods to overcome this. First, determine how your land will be used and what crops you’ll be planning on growing. Cover crops should be planted as annuals if you are doing a traditional harvest during the fall in North Dakota it would be best to use a cover crop that is an annual plant rather than a perennial.  If you are grazing your land or putting a cover in an area with some trees, you might want to consider a perennial plant that will come back every year.

Principle 4: Soil Armor

Cover crops are important because they make sure that soil isn’t disturbed and the living roots provide nutrients for the ecosystems they contain, but they have a third function. Cover crops ensure that soil is shaded from the sun and keeps the soil cool. On a hot day concrete can easily get to 140 degrees Fahrenheit and soil is no different. Cover, even if it is dead organic matter, is better than no cover for keeping your soil healthy. When plants make a canopy covering the soil effectively this soil armor can make the area much cooler than a barren landscape. The day and night-time temperatures stay much more stable and produce more consistent rainfall than areas that do not have significant cover. If you have livestock, they will also tend to be more comfortable, even in the heat of midday.

Principle 5: Diversity

Nature does not like it when there is only one plant grown in one area.  This is known as a monoculture and it is a staple of commercial farming. Weeds are nature’s attempt to repair soil that has been planted with one crop or soil left bare. In North Dakota, for example, there are over 250 species of native grass and flora that grew in the soil. Amazingly, most of these plants are still here. Underneath our feet is an enormous seed bank of native seeds that are waiting to be regrown. If you have ever seen a cottonwood tree growing by itself in the middle of the prairie, that is an example of a plant from the seed bank growing. 


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Plants and insects in nature do not overtake each other because each plant and animal has a role to play in the ecosystem. When you have nothing but elm trees planted, it makes it easy for dutch elm disease to spread because there are many potential plants to infect. Pest insects can eat crops in large numbers because there is plentiful food available and no predator insects around to keep them in check. 

Cover crops are a great solution to this problem but when you plant cover crops they too need to be many diverse species to work properly. If planting row crops, a mix of several cover seeds are recommended for maximum effectiveness. Nature needs as many different plants growing as possible. 

Principle 6: Animal Disturbance

Most of these principles of soil health alone will improve your soil drastically and do well to conserve it.  But if you want to truly regenerate soil, Animal Agitation is the keystone of regenerative agriculture. Animal agitation and waste give plants nutrients and new places to grow. In every context, there is some form of herd animal that can agitate the soil. Agitated soil can bring water to plants or allow roots to grow more easily. Nutrients that plants and Fungi make get cycled through the animal and through its waste get put into new areas. This in turn gives seed in the seed bank a chance to grow.

How did we get here? Why do we need to rethink soil practices?: 

The Green Revolution is considered the moment that our world changed forever.  With the invention of chemical fertilizers and pesticides, coupled with large-scale mechanized farming there was a brief period of time where humanity felt that it was merely a matter of time before world hunger would be solved. With green revolution practices, we could grow produce in the desert, have growing yields every year and make farming more efficient than we’ve ever seen. With these new technologies, farmers used more of the land they owned to plant more crops. Wetlands could be drained and farmed profitably and pretty soon all available land was converted from natural environments to monocultures.

However as the years passed, scientists began to notice that birds, insects, and grasses were going extinct, water quality was getting poorer, and every year more nitrogen was being used for the same crops. Topsoil was disappearing despite conservation efforts put in place since the Dust Bowl. And they began to search for the reason why.

As farms moved to specializing in a few basic crops, they ran into a problem. Planting only one crop in an area pulls nutrients out of the soil. Crop rotation processes can slow this down but every year the soil keeps losing organic matter. As soil keeps losing nutrients, it means that plants are weaker and more susceptible to insects eating them. Pesticides kill the insects but pesticide kills and weakens the microbes and animals in the soil ecosystem and makes plants vulnerable to getting sick. To solve that, fungicide was used to keep the plants healthy but even further weakening the soil. Pollinators of the crops have been decreasing for years because pesticide use has increased. Some chemicals that we used such as DDT were linked to birds being unable to reproduce and have been subsequently banned, but even the less dangerous chemicals that we used created plants and insects that developed resistance to them. More nitrogen needed to be added every year. The lack of microbes in the soil meant weaker plants that were more susceptible to disease. The fungicides damaged the natural fungi in the soil that also aided plant growth and produced material that made the soil stick together.  

This type of agriculture results in farmers paying more money each year for fertilizer, pesticide, fungicide, and seed that is specially modified and treated to grow. The question that we have to ask is ”What can we do to break this cycle?”.

Four Tools and The Power of Observation Can Help You Determine Your Soil’s Health

 It takes 4 simple tools that are easy to carry to check your soil health: a shovel, refractometer, garlic press, temperature meter, and most importantly your own observation.  This is something that anyone can do at any time of day to see how healthy their land is.

Shovel

You’ll want a thin, 2-3 foot long spade that preferably has a metal handle instead of a wooden one. This will aid you because you will be trying to disturb the ground as little as possible and you will be shoveling deep to get a true idea of what your soil looks like. Make a slit as deep as you can and only try to dig one shovel length. If your soil is incredibly hard, just dig down as low as you can. Try to break as few roots as possible and only pull your shovel up minimally to just start to expose the earth. The first thing that you should look for is the crust on the soil’s surface.  Ideally, there should be none to very minimal crust in healthy soil. If you have a thick hard crust your plants cannot grow well and water doesn’t absorb into the soil easily. The second thing to look for is the color of the soil. The darker the soil, the more organic material it has and more living it is. It should have the consistency of black cottage cheese hanging from the roots,  the next thing to look for is how deep are the roots and are they living?  The roots should be moist and sticky and reaching down. Keep in mind as you are doing this your soil can vary a lot in as little as 5-10 feet of surface area. It’s not uncommon for some parts of the soil to be healthy and robust and others to be almost dead, and somewhere in between. Make notes of how many different species of vegetation you can spot. Your job is to identify the biological hotspots on your land and to try to grow them outwards. This can be anything from the size of a single cow patty, the banks of a stream, or the shadow of a tree.  Your context will determine where your hotspots are.

Refractometer and Garlic Press

Another simple test that you can perform on your pasture is with a refractometer and a simple Garlic press to examine your Brix levels. Brix is a measurement of how much soluble sugar is in a plant at any given time. There are two types: Fruit Brix and Leaf Brix. We’ll be focusing on the Leaf Brix. When measuring, make sure that you are referring to a Leaf Brix chart to get an accurate reading. To do this test, you’ll want to take a sample of some untouched vegetation that you have observed your cattle eating. Try to stay away from the eaten materials because the plant will be repairing itself after being grazed and not give you a truly accurate picture. Roll the organic material into a ball in your hand and take the garlic press to squeeze the liquid out and follow the instructions on your refractometer to tell the Brix level.  The ideal healthy level that you should be looking for is 12-14 Brix. Because the heat of the day can change your plants’ Brix level 12 is the absolute minimum you want in order to regenerate your soil. 0-2 Brix means the plant is nearly in the grave, 3-7 means that they are dying but have a fighting chance, 8-11 is when they are stable but slightly strained. When plants have a high amount of dissolved sugars from photosynthesis, the roots will pump out the excess sugars as a waste product. This in turn feeds microorganisms living in the soil. 

Temperature

Temperature gauges that have been prevalent during the COVID outbreak can be useful when monitoring your soil. They’re also as simple to use as point and click. Ideally, you want shaded soil that can stay in the 70-80 degree temperature range. Soil temperatures in the 80 to 100-degree range cause bacteria to start shutting down, 100-120 degrees can start killing 40-60% of the bacteria living in it. Bare exposed soil can easily reach 120 degrees and effectively kill 80% of bacteria living in it and by 140 degrees there will effectively be no living organisms in your soil.

Observation

The last and most important is observation. You can do all these tests perfectly but it doesn’t mean anything if you don’t record your observations and change your practices to accommodate what you are seeing. Ask yourself if you are seeing more or less diversity. Is there more animal and insect life in your pasture or field?  A good rule of thumb is to watch for birds. Do you see more or fewer birds flying around you? Is your crust getting thicker or thinner on your soil? How much rain did you get? Is your Brix getting higher or lower? What is your average soil temperature? Is it going up or down? What do your cows’ patties look like?  Are they flat? Piled up? Runny? Do you notice how much cover your soil has? Are your biodiversity spots growing or shrinking? Note your trends and consider what changes you need to make.  

Soil health is a journey, not a goal.  We all have a long way to go to restore our soil and it will take a lot of work to get it back where it can regenerate effectively. For more information, you can go to websites such as http://brownsranch.us/learning-resources/ to learn more about principles and practices of soil health. You can also contact DRC Ag Organizer Sam Wagner at sam@drcinfo.com.


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