Pasture Management
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Before Europeans settled
the United States, grasslands stretched across most of the
Midwest. Here in Northfield we are right on the edge of what used
to be part of the prairie ecosystem. These grasslands were
maintained by a combination of climate, fire, and grazing by native
herbivores. Herds of bison would graze and trample an area of
prairie only to move on and let the grassland that they left behind
rest
and recover. Today, we have changed this landscape
drastically. We have mowed it down to grow crops and we have
fenced in our domesticated animals to graze in confined areas.
But, the way the grassland ecosystem works is still the same as it was
when the bison roamed free. We need to look back at how the
relationship between the pasture land ecosystem and the free roaming
herbivores worked to come up with sustainable environmentally friendly
management practices today (Paine and Lyons, 1999). There are a lot of benefits to increase the productivity of your pastures. It can help to decrease the amount of hay that has to be bought. The labor and equipment used to harvest forage can be reduced. Well managed pastures need to be fertilized with commercial fertilizers less and can decrease time spent cleaning stalls (Wegner and Halbach, 2000) And your horses can enjoy the food that is best for them, fresh grasses and legumes, which will contribute to their health and happiness. Good pasture management can double the total forage produced in a field (Undersander and Antoniewicz, 1997). Good pasture management can also have environmental advantages. Pastures increase ground cover and prevents soil erosion. Healthy pastures also require minimal pesticides and fertilizers and they can decrease the amount of barnyard runoff. Many native grassland birds such as sandpipers, bobolinks, and meadowlarks, as well as other birds and wildlife are given more habitat (Undersander, et. al, ?) Usage: Pastures that are used for different purposes can be managed quite differently. There are uses that a smaller, well drained lot that may not have any forage, can be quite suitable. For example, an area for the horses to get exercise or stay when they need to stay off the better pasture. But, if the pasture is to be used for nutrition, many considerations should be taken into account (Undersander and Antoniewicz, 1997). Soil and forage: It is best to try and maximize a pasture's soil fertility. Fertility of the soil means that the level of essential nutrients that are in the soil and available to plants is high enough for good productivity. Soil can be tested to ascertain the make up of a pasture's soil and what nutrients are lacking or over abundant. If nutrients are lacking, a commercial fertilizer or manure spreading may be needed (Wegner and Halbach, 2000) Horse pastures are ideally primarily made up of grasses and legumes. The proportion of legumes to grasses will at least partially determine what nutrients are needed in the soil and how much gets recycled. A pasture with mostly grass and fewer legumes will probably need more nitrogen to be added than a pasture with few grasses and more legumes. Weeds are also a part of every horse pasture, even though it would be great if they all disappeared. Weeds can be controlled by rotational grazing, mowing, hand pulling, or chemically treating weeds when horses are elsewhere (Wegner and Halbach, 2000). Chemically treating pastures for weeds should be done with extreme care and only when there is dire need. According to the University of Minnesota, the best mix of pasture forage includes alfalfa, smooth bromegrass, orchard grass, and white clover for Minnesota pastures. But, if pastures are overgrazed this mix will be reduced to bluegrass and some thistles. So, it is recommended first that pastures are not overgrazed or secondly to substitute bluegrass and white clover for the alfalfa. This combination will be able to withstand more grazing and form more tight sod to resist trampling by the horses (Wegner and Halbach, 2000). Grazing: Grazing in itself is not bad for pasture plants. Plants from grasslands have been getting grazed on for a millennia and have developed ways of coping with grazing. Some grazing can stimulate pasture growth because old or dead leaves no longer shade young leaves (Undersander et. al, ?). But horses are one of the hardest animals on pasture. Cattle, sheep, and goats have a special organ in their digestive tract, the rumen, which is full of microbes that breaks down most plant fiber. Thus, they are very efficient digesters. Horses do not have a rumen and are called "pseudeo-ruminants." They do have microbes in their digestive tract that breaks down some plant fiber, but they must graze longer than true ruminants to get adequate nutrition. Cattle graze about 8 hours a day while horses can graze 12 to 16 horses a day. (Undersander, et al, ?). Over grazing is one of the worst problems more pasture productivity. If pastures are continuously grazed from spring to fall the pasture will not be able to keep up its productivity and as a result, weed populations will gain a much better hold and some species of grasses and legumes will not be able to survive. Only a few forages such as Kentucky bluegrass, white clover, and some low growing weeds can do well under continuos grazing. The other forages that are taller need time to recover from being grazed so that they can stay ahead of weed populations. Healthy forages will also be able to better survive a drought in summer time (Wegner and Halbach, 2000). The solution to keeping pastures from being over grazed is rotational grazing. This means dividing big pastures into sections and rotating the horses through the sections to allow forages to re grow and recover to remain healthy. The University of Minnesota Extension service recommends that each section be grazed for about three to four weeks and then experiment with lengths until you find the right amount of time for your situation. Horses can be let out on a pasture when the forages are at least 6 to 10 inches long and moved from that pasture when the forages are down to 3 to 4 inches (Wegner and Halbach, 2000). To find the right amount of time for rotations think about the growth stage and rate of the forage rather than strict time schedules (Undersander et. al, ?). There is no set number of how many sections a pasture should be divided into. The number of paddocks can be dependent on topography, access to water, and the current fencing situation. Practically any divisions are preferable to one continuously grazed pasture. You can think of the percentages of rest versus grazing when there are more divisions. If a pasture is divided into two sections, each section is resting 50 percent of the time. If a pasture is divided into four sections, than each section is resting 75 percent of the time and so on (Undersander, et al, ?). Every farm and pasture will have individual needs so it is a good idea to check back and reanalyze a management plan every so often. Well managed pastures won't need as much fertilization, but grazing will still deplete the soils nutrients so an annual soil test is still a good idea. Horses eat about 1 to 2 percent of their body weight in forages every day. This means that a 1000 pound animal will eat about 15 to 20 pounds of pasture forage every day. This translates to one horse for two to four acres of pasture as a general rule of thumb. It makes no difference whether this is one 1000 pound horses or two 500 pound horses. Some pastures will be able to support more or less, and well managed pastures that utilize rotational grazing should be able to support more. Heavier or lighter stocking rates can lead to over grazing or under grazing. Under grazing can lead to more mature and lower quality forage. Stocking rates can also be flexible when conditions change, such as a horses in heavy or light work, pregnant mares, low soil fertility, drought, or if the pasture is made up of low-yeilding species such as Kentucky bluegrass (Undersander and Antoniewicz, 1997). |
Reversing damage:
"The
return to nature affords the very means of acquiring the
incentive and energy for ambitious and constructive work of a high
order" (Berry, 1990).
Pastures that have already been over grazed need special attention. One way to rejuvenate a pasture is to re seed it with legumes. The University of Wisconsin recommends that before seeding it is best to test the soil for its pH and its fertility. If the pasture is not at optimum fertility or pH, seeding may have a limited chance of success. It is also best to test the soil of a pasture in several different spots that may have different coloring or constitution. Samples should be taken at a depth of six inches and not taken from road sides, field borders, or from distinctly different areas such as sandy ridges or eroded spots. When you send it to a laboratory ask for analysis of the solid pH, phosphorus, and potassium. The soil test recommendations will tell you if you need to adjust the soils pH by adding lime. Lime needs to be applied 3 to 6 months before seeding and it is best to lime in the fall or earlier and to seed in the spring for the best legume stands (Undersander and Antoniewicz, 1997).
One more step before actually seeding is to control the weeds in the pasture. This can be done by mowing one or more times or the timely application of an appropriate herbicide. The University of Wisconsin stresses that the time is very important when applying an herbicide. If an herbicide is applied at the wrong stage of growth for the weeds, it will not control them very well (Undersander and Antoniewicz, 1997).
Frost seeding and no-till drill are the two methods for seeding legumes into grass sod recommended by the University of Wisconsin. Frost seeding is the practice of broadcasting legume seed on the pasture surface in the spring after the snow is gone but while the ground is still frozen. The fall before seeding the pasture should be grazed down very short so that the seeds can fall on the soil surface. Then in the next early spring, broadcast red clover at 2 to 4 pounds per acre or birdsfoot trefoil at 4 pounds per acre. This type of seeding is inexpensive and increases legumes, but it does not provide a uniform mixture of grasses and legumes. The success of frost seeding also depends on the spring whether needing cool moist periods (Undersander and Antoniewicz, 1997).
No-till drill seeding places the seed directly into the soil. This method is more expensive, but it is more reliable and provides more of a uniform grass and legume mixture. The seeding rates are the same as for frost seeding (Undersander and Antoniewicz, 1997). The University of Minnesota Extension service tells us that many extension services in Minnesota will rent out no-till drills for relatively inexpensive rates (Wegner and Halbach, 2000).
To give the seeds the best chance possible, the University of Minnesota recommends a spring seeding when the pasture grasses are five to six inches tall. It may also be necessary to apply a glyphosate herbicide like Roundup at a low strength to help new seedlings take hold over the more mature plants. And of course, adding nitrogen may be necessary. A soil test can help to tell you whether your pastures need a nitrogen fix through manure spreading or a commercial fertilizer (Wegner and Halbach, 2000).
Management Practices:
As has been stated previously, a well managed pasture can have many benefits. Here are some basic tips to building your own management plan that are provided by the University of Wisconsin (Undersander and Antoniewicz, 1997).
- Make sure that the stocking rate, or body weight of horses per acre is in the correct range.
- Inventory your resources. Draw or obtain a map
of your property and find where topographical features or soil types
will need special consideration. Have your soil tested so you can
base your practices on correct information.
- Plan a rotational grazing system.
- Undersander pasture plant and growth patterns and
needs. Grasses begin growth in early spring and produce half or
more of their yield in May and June. They don't grow very much
during the hot months of the summer and then start growing again in the
cooler whether of fall. Nitrogen fertilizer is immediately taken
up and used only for the current growth period. Nitrogen will
probably need to be applied three times annually in April, June and
August. On the other hand, legumes begin to grow later in the
spring but grow more in the summer months. Legumes need more
potassium and higher soil pH than grasses do. If the growing
conditions are good, legumes can fix their own nitrogen for later
growing periods.
- Manage grazing to the benefit of both horses and
pasture.