I am sure you are all aware that the soil is the foundation for all plant life on Wyoming rangelands. But did you know that the health of those plant subsequently affects the health of the soil? It is one giant circle—the circle of life.
In the fall rangeland grasses begin to go dormant. Growth that was not consumed by grazing herbivores falls to the soil surface and begins the decomposition process. Plant litter, manure, and carcasses decay and nutrients from these items are incorporated into the soil. Healthy soils are characterized by organic matter and nutrient availability. Healthy plants create litter, which create organic matter and nutrients, which increase soil health. Healthy soils support healthy plants, which support healthy soils.
I am also sure that you know that plants need four things to grow, 1) sunlight, 2) carbon dioxide, 3) water, and 4) nutrients. Sunlight and carbon dioxide are obtained by absorption by the leaves from the air, and water and nutrients are obtained by absorption by the roots from the soil. Plants need robust root systems in order to fully take advantage of nutrient and water reserves in the soil. In-order to grow robust root systems there needs to be adequate green leaf material above ground for the plant to generate energy through photosynthesis. This energy then allows the plants to develop new roots, shoots, leaves, flowers, and seeds. Think about when you plant a new tree in your yard… The first few years there is very little if any above ground growth. This is because that tree is establishing the root system needed for survival. Most of the energy that is created by photosynthesis is going into growing roots, not shoots or leaves. One the root system is big enough to take up enough water and nutrients to support both below and above ground growth, that tree begins to put out more branches, get taller, and bushier. The same is true for rangeland grasses.
What if we add properly timed grazing into the circle? When green plant material is removed, the amount of photosynthesis it can perform is greatly reduced, which reduces the amount of energy produced. Healthy plants are able to combat this by pulling energy stored in the roots to develop new shoots and leaves. This new plant material creates more energy and stores it back into the system through increased root growth. This root growth allows plant to adequately withstand drought, grazing, and fire, as well take up the nutrients needed for continued growth. Grazing also has secondary effects. Activities such as hoof action and manure deposition can help increase soil health. Hoof action incorporates nutrients from decaying plant and animal material into the soil. By removing manure deposition and hoof action the potential for increased soil health decreases. This decrease in soil health can cause a subsequent decrease in plant health over time.
Soil health and plant health are intertwined. When soils are in poor health, plants are in poor health and vice-versa. By properly managing livestock grazing both soils and plants have the potential to lead very healthy lives.