This article was written for the Boulder County CSU Extension’s “Spring 2008 Small Acreage Newsletter."

This article references a chart called the "At a Glance Calendar. Click here to view the PDF file.

Grazing Made Easy: March 2008

by Deniece Hopkins of Lone Cowboy Enterprises —

Are you a grass farmer, a weed farmer, or a dirt farmer? Too often this question answers itself based on grazing management. Oftentimes, people may start out with good intentions—and for a long time do really well with their pastures—but forget to alter their management based on current climate conditions.

As a drought or even a very wet season comes along, grazing management must be altered to protect your pastures. The intent of this article is to simplify grazing so you can make the decision to graze based on what you see, rather than what the calendar says.

One of the first things you must do—and probably the hardest—is to throw away all your preconceived notions of what has “always worked” or worked in the past. Then, you should divide your grazing area into cells. It’s best not to make these permanent divisions since you might need to make slight alterations to the size as you gain more experience. Temporary fences (fiberglass or plastic step in posts) are excellent for these purposes; and not very expensive.
The minimum number of divisions for this to work is four. This can be effectively used even for 1-2 acre pastures. You must also include a “sacrifice” or “dry lot” area to place horses any time your pasture doesn’t meet the 6-8” grazing height criteria. This sacrifice area needs to be large enough to provide the horse with sufficient room for exercise, as they will probably spend a majority of their time in this area. A sacrifice area is truly that: it will go to dirt; but will save the rest of your pasture.

Using this grazing system, horses are allowed in only one cell at a time. As the cell is grazed down to 3-4” inches, or 7 days, whichever comes first. An important rule of grazing management is “take half and leave half”—only allow the horses to take half of the forage they start with in that cell, then move the horses to the next cell (provided the next cell has reached the 6-8” grazing height).

The previously grazed cell will now have time to rest and recover from not only the removal of grass, but also the pressure and damage made by horse traffic. On irrigated pastures, recovery may take 30 to 60 days; whereas dryland pasture may not recover for the entire season, leaving that cell unable to be grazed for the rest of the season. This is a key piece of information: it is very typical for dryland pasture to only be able to be fully grazed once during a calendar year. There are many articles written to help you divide your land into cells and help you understand all the scientific reasons for doing so. Please note that a few are listed at the end of this article.

Now that your pasture is divided into cells, and you understand the basics of cell grazing during the grazing season which mid-April—mid-Sept as indicated in yellow on your “At a Glance Grazing Calendar.” (The yellow indicates caution so you need to look at your pasture to determine if it meets all the necessary criteria for grazing: is it tall enough, is it dry etc.)

There are 2 times of the year that you must not graze or even have your horses on the pasture. These times are indicated in red on your “At a Glance Grazing Calendar.” These would be approximately mid-February thru mid-April and mid-September thru November.

The first period, February thru April, is when the grass is coming out of dormancy. It is easy to tell this time of year, by walking your pasture and looking for the green coming up from below the dead grasses. These are the new grass leaves growing out of the grass plant crowns. It is necessary for them to grow undisturbed so they can replace their carbohydrate reserves in the crown and roots used for late winter thru early spring growth and for growth throughout the grazing season. To graze now would prevent the grass from obtaining the necessary leaf surface to photosynthesize and replace the root energy reserves used for the first growth of the year and after grazing. Hoof damage to the crowns will also stop growth and stress grass significantly; and the damage may not be immediately evident, but the following year the pasture will be significantly less. Damage in the fall and winter to grass buds on crowns will diminish grass vigor the next spring.

It is best to wait to initiate spring grazing until the grass reaches the 6”-8” grazing height. This will require you to walk your pasture and measure your grass height. Grazing too soon in the spring is probably the No. 1 grazing management mistake, and will have a long term negative impact on your pasture—and in our arid environment can quickly turn a beautiful pasture into a dirt farm.

The second period is September thru November. This is the time when grass is going into dormancy and is again building energy reserves for the dormant period. Four to eight inches of leaf area must remain in order for grass to sufficiently store needed root energy to survive the winter and come back the following spring.

After grasses have browned and gone completely dormant is a safe time to graze your horses (indicated by the green area on your calendar). As long as the pasture is dry, the horses can cause little damage to your grass. The remaining brown grasses also contains some residual nutritional value to the horse, but is mostly an energy source. However, there is possibility of some damage to grass crowns due to trampling and excessive removal of mulch material during the period, so heavy use of the pasture is not recommended.

Note the stop sign on your calendar, which indicates no grazing when pasture is wet. Any time, in any season, when the pasture is wet from snow, rain or irrigation, a horse will cause extreme damage to your pasture grasses by causing excessive compaction and root and crown damage. Avoid having any animals on wet pasture at any time.

Also, included on your “At a Glance Calendar,” is the chart for grazing time based on available space and number of horses. The chart assumes you will use rotational cell grazing and that cells have reached 6”-8” tall prior to grazing. Only leave them on for the time indicated by the chart, and also take into consideration the condition of your pasture.

It takes a very short time of poor grazing management to do years worth of damage to your pasture. By monitoring your pasture closely for signs of the grass growth cycle, and following the guidelines above (and available from other CSU Extension publications), you will be able to protect your pasture for the pitfalls of over grazing; and provide a pasture suitable for happy horses.

ADDITIONAL READING:

"Grazing Made Easy" copyright © 2008 Deniece Hopkins. All rights reserved. To reprint this article, please contact us.