Managing Small Pastures

Small pastures are particularly susceptible to overgrazing (too many grazing animals for too long). Many people overlook the importance of managing these pastures and consequently, they are the most commonly abused grazing lands in the county. Management principles are the same for small pastures as for large ones and equally as important. The basic steps are as follows:

Decide How You Want The Pasture To Look
Do you want a mix of grasses and shrubs, shrubs only, grass only, or bare ground? Knowing your desired landscape is the first step in managing a small pasture. Too many animals (be it horses, cattle, or llamas) leads to bare ground on dryland, and a thick short sod on well irrigated pastures. Animals can also be used to manipulate the composition of a pasture. Animals, such as goats or sheep, selectively graze forbs and brush and make them less prominent over time. Conversely, cattle or horses select the most desirable grasses and foods, thus forbs, brush and unpalatable grasses become more prominent in the pasture.

Use The Basic Principles Of Good Range Management
There is more than one principle of pasture management. It is easiest for smaller pastures to adhere to the “take half and leave half” principle. This idea is that by only grazing one-half of the available and desirable forage and leaving half, the existing plant community is sustained at that stocking rate. By not grazing too much of a plant, the plant is allowed to regrow and replenish its energy root reserve.

A second management principle is grazing time. Grazing too early in the spring does not allow the plant to replenish its energy reserves and consequently, it cannot regrow as fast as other ungrazed grasses. Impacts on a plant from grazing vary throughout the year and growing season. Plants are most severely affected from grazing during seed formation when they need maximum energy to produce seeds. The least critical time for grazing is dormancy (i.e., late fall). Grasses grazed while dormant are not adversely affected as the plant has already stored energy, therefore, grazing or leaf removal has little impact on the plants ability to regrow the following spring.

Estimating The Carrying Capacity
There is no standard reference on the amount of available forages for different pastures in the intermountain west. Dryland pastures in Routt County typically range from 300-2000 pounds per acre in total usable dry matter. Irrigated pastures range from 2000-6000 pounds per acre. “Typically,” dryland in Routt County produces 1000 pounds, decreasing as you go toward more arid environments in the west. Thus, a “typical” dryland pasture has around 500 pounds of usable forage (dry matter basis) per acre. To know for sure, clip a small area that is representative of the pasture and weigh it after allowing it to air dry for three or four days, or obtain an educated guess from a local “expert.”
• Grazing animals need 2-3% of their body weight of air-dried forage daily. Thus, a 1000 pound cow needs approximately 25 pounds of air-dried forage a day or 750 pounds of dry forage per month. Therefore, a 1000 pound cow needs 1.5 (or almost 2) acres per month.
• Horses are the same, but they tend to waste and trample more forage, and 3-4% of their body weight per day is more typical.
• Sheep need 2-3% of their body weight, however, they utilize a higher percent of brush species and forbs than cattle or horses.
• Llamas tend to have slightly more efficient digestive systems and require only 1.8-2% of their body weight of air-dried forage daily.

To estimate the total carrying capacity of a pasture take the estimated air-dried forage
production divided by 2 times the number of acres:

estimated air-dried forage production
2(number of acres)

This is the total available production of the pasture that will sustain the existing desirable vegetation.

Then calculate the needed forage to sustain all the animals for a day. Then divide forage availability by forage need to discover the amount of days the pasture can sustain grazing during the growing season. Or you can save yourself from all of this and call the Agriculture Agent at the Extension Office, who will do it for you.

forage availability
needed forage

Tips And Ideas For Improving Small Pastures
A combination of herbicide and brush hogging (heavy duty rotary mower) is the best strategy for lasting removal of sagebrush. Brush hogging alone will remove all existing material but the brush grows back after 2-3 years. By brush hogging first and then treating the new growth with an herbicide there is a much greater success rate (80-100% removal). This also allows for a lower herbicide dose as the plant is already stressed from the brush hogging.

Encouraging More Grass
• Be sure grazing is not so severe that it reduces grass. If so, reduce the amount or severity of grazing or allow for longer rest periods.
• Keep animals off pasture in the spring until there are four to six inches of grass growth.
• Use a rotating grazing scheme. Rotation grazing refines the “take half and leave half” principle and lets you manage your pasture more intensively. This can lead to more forage production and greater carrying capacity. Seek additional advice from the Extension Office before implementing a rotation-grazing plan.
• Weed Control. Many pastures that have historically been abused or allowed long-term rest will have more broadleaf plants and brush species than grasses. Applying a broadleaf herbicide suppresses the broadleaf species and aids the grasses re-establishment of dominance. Prior to herbicide application, carefully read the label and adhere to the rate recommendation and grazing interval. Be particularly careful in spraying poisonous plants as many herbicides change the sugar composition of poisonous plants, making once unpalatable plants palatable and more likely to poison livestock and horses.

• Reseeding or interseeding. In worst case scenarios where a pasture is severely overgrazed or weedy, use reseeding as an alternative. There are two methods: plow disk and drill, or application of a broad-spectrum herbicide and drill into dead plant matter. Each method has advantages and disadvantages. Therefore, seek additional advice before reseeding. Reseed with a mixture of grass plants, not just a single variety to insure a greater chance of establishment. Common grasses in seed mixes for dry land should include smooth brome (one of the wheat-grass types), and may include Piute orchard grass, or perennial rye grass.

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