The Science and Art of Grazing Small Acres: Part 1 The Science
 | Author:
Allison Kosto, MSU Broadwater County Extension Agent
MSU Broadwater County Extension Agent |
The Science and Art of Grazing Small Acres, Part 1: The Science
Allison Kosto
MSU Broadwater County Extension Agent
If you are new to owning property and/or livestock, you quickly see there is a steep learning curve when it comes to land stewardship. Even if you have owned property, the environment and conditions in Broadwater County are vastly different than other areas of the country, even different than other areas of Montana. It’s quite easy to overgraze property, especially on small acres. And once the land is overgrazed, it's even more difficult to bring it back into good health, often taking years.
When grazing management is done correctly it can provide benefits to the land including stimulating growth, removing dead plant material, reducing wildfire threat, increasing nutrient cycling and increasing forage production. However, when land is overgrazed, it can lead to many issues including the prevalence of weeds, increased use of herbicides, poor forage quality, lack of plant diversity, reduced land value, and increased erosion, water runoff and nutrient leaching.
There is a large amount of science behind grazing management. However, there is also an art to grazing that takes some trial and error to determine what works best for your property. This week, I’ll focus on the science behind grazing. Next week, I’ll share some of the art and specific tips to managing grazing on small acres in Montana.
The science of grazing management starts with a focus on plant health and biology. Start by evaluating your current pasture or rangeland health. There are many factors that will influence forage production including soil type, weather, precipitation, plant type, pasture history and topography. If you have dryland pasture, forage production is much more limited than on irrigated pasture. In Montana, you cannot graze dryland pasture year-round. The grazing window is very small. On the other hand, irrigated pasture allows your much more flexibility, extends the grazing window, improves drought tolerance and even can provide a little more forgiveness for overgrazing.
Different species of plants respond differently to grazing pressure. Some plants will decrease under grazing pressure. Many of these plants are highly palatable so are often grazed more heavily. Additionally, they may lack plant features to allow them to recover successfully and quickly. Examples are bluebunch wheatgrass, western wheatgrass and green needlegrass. Other plants will increase under moderate grazing pressure. These plants are often less palatable and have mechanisms that allow them to recover faster. Included in this category are many weeds including cheatgrass. Knowing your plant community is a crucial step to understand how it might respond to grazing pressure.
When a plant is grazed too close to the ground, there are fewer leaves remaining for the plant to photosynthesize to replace the leaves that were removed. This means the plant is slower to recover or may never recover. The other negative effect of grazing a plant too close to the ground is that it reduces root reserves because the plant needs them to produce new leaf shoots instead of establishing strong roots. When adequate plant material is left above ground, the plant can recover quickly by producing more leaves and also enables the plants to develop a stronger root system. The rule of thumb when it comes to grazing and removing plant material is ‘take half, leave half’. This typically achieves an appropriate balance of maintaining enough leaf area for plants to successfully recover.
Another important consideration is the number and type of animals. There is a large amount of research and scientific calculations that can be done to determine the appropriate stocking rate for grazing. However, for small acreages, that probably isn’t necessary. It's simple to understand that the more animals you have on a piece of property, the more quickly the forage will be removed. Species of animal also plays a role. Size of the animal is obviously a factor; the larger the animal, the more they will eat but animals also have different grazing behaviors. For example, sheep and goats are more likely to eat forbs while cattle and horses prefer grass.
Stay tuned next week for more on the art of grazing and specific tips to help you manage your property. If you have further questions, stop by your local MSU Extension Office at 416 Broadway or contact us at 406-266-9242 or allison.kosto@montana.edu.
