August 22, 2005
Why pay attention to your soils? Long-term soil health is directly related to how much money you can put into your pockets. Soils and soil quality determine plant vigor. Soil organic matter content is the key indicator of soil health.
Soil organic matter is important for maintaining soil structure. Soils with good soil structure generally have lower erosion rates, higher water infiltration rates and higher water-holding capacities and also serve as an important nutrient reservoir.
Besides, I say, “If you can learn to feed the soils, the soils will feed you.” Healthy soils equate to a healthy life. Healthy soils are alive with all kinds of small critters living in them, eating away, making carbon, the black color in soils, called carbon sequencing.
So it’s just logical, that if we can estimate and learn how to sustain and even improve soil, you can then capture more ‘solar dollars’ (a free source of energy). You won’t have to go to town and buy that same energy with ‘paper dollars’.
A client of mine once asked me, “Wayne! What is the fastest way to grow more soils?” I thought about that question and responded: Find a chunk of long-term rested ground, like 10 year old CRP land—highly erode-able land set aside for conservation and government payment.
Then graze and trample all that old dead non-cycling plant matter into the ground. Do this during a dry, non-growing time. By doing this, you have just speeded up a healthy soil making process by incorporating new organic matter.
The biological principle here to remember is: Down yellow litter, feeds small soil critters.
How to determine soil health:
I pull a plug of soil, 2” x 2” x 4” deep, that fits nicely into my hand. I then photograph this plug for record keeping. I use a digital camera and snap a picture holding the plug up in the air with the background location of where I dug the plant. This gives me fast visual upper surface soil profile record.
I use a small trowel, two inches wide and four inched long that has a bent handle which allows me to tap it into hard ground with a small hammer. This saves me from packing a heavy shovel around in remote pasture locations.
I can see and feel certain soil health indicators in this plug (see photo). There are 3 key soil health indicators that I look for using this method: Soil type, soil organic matter content, and soil compaction.
I first look for soil compaction, because that is the one healthy indicator that we have some control over. Compaction problems visually show up below the surface organic matter as shiny smooth layers of soil, all pushed together.
Monitoring this way I once found heavily compacted soils, where the roots would only grow in the cracks of the clay soil, which was responsible for greatly lowering the forage production.
I next look for organic matter content. Organic matter is the vast array of carbon compounds in various stages of decomposition. Visible organic matter shows up as thatch (dead and decaying plant parts in the very top layer), roots, and occasional underground bugs and worms. Another item to look for is the very small black particles that give soils that great earthy smell. These are the results of organic mater decomposition.
I also determine the type of soils I sample. Take a small portion the soil from the plug in your fingers, wet it and rub it between your fingers.
If the polishes make a shiny smooth sticky coating on your fingers and is grayish brown, it’s probably clay,
If it feels very smooth and slippery, but not quite polished and is dark tan, it’s probably silt.
If it feels gritty (small sand particles), and is light tan, it’s probably sandy soils.
If it crumbles and is dark in color, not especially gritty, smooth and shiny, you probably have a loamy soil.
In reality, there are all kinds of different soils. Usually in mixtures of all these different elements, but you can come close to what the major soil types are. Each soil type has their inherited limitations and advantages.
What’s handy about this way of assessing soil health is that you can quickly compare one area to others. For example, I thought I had found a compaction problem in one pasture I was inspecting one day. So I dug a soil plug, and found no compaction. This soil was full of small stones, rocks and sand which does not compact. You need that sticky clay particle to form a compaction layer.
Another example that surprised me was on inspecting a grazing cell center where the water and fencing configuration is built like the spokes of a wagon wheel. We found tall grass all around the cell center. However, when I went to dig up some chucks of sod to observe the root structures, I had to jump up and down on the shovel like a mad man. We had nice tall healthy looking grass, but the heavy clay soil was very compacted.
Just adjacent to this cell center was an area fenced off from livestock grazing, that we called the “TEST REST AREA”. A long-term observation area of what no grazing looks like. I went to jump onto the shovel in this small fenced off area and about fell on my face. My shovel easily fell into this soft fluffy soil.
What’s going on here?
Compaction on the outside was caused by livestock grazing and soft fluffy soils appeared on the no-grazed area! This cell center was constructed on heavy gumbo clay soils. Gumbo is on of a variety of fine-grained soils that become waxy and very sticky mud when saturated with water. When these soils are highly compacted and dry out, they become very hard, and would make fine bricks.
However, comparatively speaking, the grass was much thinner and shorter in the non-grazed area The owner of the non-grazed lands walked by this exclosure and told me, “Long-term rested soils do not grow good cow feed, and Wayne, it doesn’t even pay taxes”.
The lesson learned here: If you graze livestock at high stock densities, be careful of compaction. Plan alternative areas and enough rest to allow these compacted soils to fluff with spring and fall frost heaving actions.
Bottom line, soil health is the key to growing strong abundant dense vigorous forage for any livestock operation. Next time you walk your pastures, dig some plugs and see what’s happening to the soils below the surface. On top of your soils follow this one controlling rule: Keep the soils covered! —Wayne Burleson
Wayne Burleson is a land management consultant working out of Absarokee, Montana. You can visit with Wayne at (406) 328-6808 or E-mail him at email@example.com. Wayne also has an educational web site at www.pasturemanagement.com.