Your horse's favorite activity could be time spent with "Dr. Green"--the horseman's name for turnout on pasture. Left on his own in a field, your horse nibbles for long periods of time. Grass forage is an important part of most horses' diets; therefore, it is up to you to maintain pasture quality. The amount of nutrition your horse gets depends on the amount of time and effort you spend on your pasture.
Forage is your horse's primary diet, whether it's hay or grazed grass. To nurture your pasture, follow these steps to assure maximum productivity.
Plan Pasture for Specific Needs
A good pasture can supply most required nutrients for a pleasure horse. A growing or breeding horse, or one in hard work, will require concentrate feed as well as grazing. In addition to being a good source of nutrition, pasture also provides an economical forage.
"Your cheapest feed is under your horse's hooves," explains Dave Robison, Forage and Turf Agronomist with Ampac Seed Company in Tangent, Ore.
A permanent pasture is a renewable resource. The plants are annuals or perennials and grow back yearly, living for three or more years. You must match the amount of pasture to the number of horses you intend to support, or you can quickly see a lush pasture turn to a dust bowl. (See "Stocking Rates" on page 102 for guidance, and realize that even two acres can supply adequate grazing for an average horse.)
Leonard Lauriault, Agricultural Specialist at New Mexico State University, advises, "For a pleasure horse who isn't running hard every day, he should do fine on pasture. But the pasture size does make a big difference."
Jeff Bader, Quay County Extension Agent, Tucumcari, N.M., says, "The less land you have, the better quality of management you need to provide your pastures. Think about your goals, and what you use the horse for."
Analyze Your Natural Resources
Pastures vary across the United States because of different climates, soils, and forage species. The USDA hardiness zones reflect the minimum winter temperatures that certain pasture grasses can withstand (see "Plants for Different Climates" on page 99). If your pasture grass can't handle the weather in your area, no amount of fertilizing or other maintenance will help.
Sample your soil to help you determine fertility and decide if you need to add anything to improve or maintain your soil at a level that suits the types of forages you are growing. You should have a soil test conducted every two to three years to get the soil's pH value. In the East, soil tends to be acidic; western states are more alkaline. Plants vary in their tolerance for these values, so you should get advice from your local extension agent or your state's university extension office on which plants do best in your area. For example, adding limestone raises a field's calcium level and corrects acidity. Plants also vary in their tolerance of salt, so a soil's salinity also can affect growth and the types of forages you choose.
You also need to know the nutrient levels of your soil. Plants need certain basic elements for growth. In general, the minerals they need most are nitrogen, phosphorus, and potassium.
Water is also essential to plant health. Since nutrients are taken up from soil and water by a plant's roots, you might have to irrigate your pastures during a hot, dry summer to maintain your forages.
Study the Plants
Grasses are known not only by species, but by weather types--cool-season and warm-season, depending on which time of year they flourish. In general, cool-season species grow best in a range of 60-80°F (15.5-26.6ºC), normally seen in spring and fall; while warm-season grasses thrive in 80-95°F (26.6-35ºC), usually seen in summer and early fall. The cool-season perennials you grow are either grasses or legumes (which have nodules on their roots that make their own nitrogen). Common cool-season grasses include tall fescue, orchardgrass, Kentucky bluegrass, smooth bromegrass, timothy, tall wheatgrass, and ryegrass. Popular legumes are alfalfa, white clover, and red clover. Warm-season grasses include bermuda, big bluestem, and switchgrass.
Some grasses are "bunch" grasses, growing from a crown or aboveground stem. Others, such as tall fescue, spread by rhizomes--horizontal, underground stems. Remember, if you have fescue in your fields and have breeding stock, beware of endophyte-infested species. (For more on the effects of endophyte-infested fescue, see "Fescue Toxicosis and Treatment" in the July 2000 issue of The Horse, online at http://www.thehorse.com/ViewArticle.aspx?ID=208.)
Robison advises not to remove all tall fescue from horse pastures. "Not all tall fescues are bad," he says. "I get calls on a regular basis, saying, 'I don't want tall fescue in my mix.' But then you won't have pasture in the summer. There are better tall fescues that are endophyte-free."
One way to improve established pastures without plowing them under is by introducing new plants. You can have a pasture with only grasses, or grow a mixture of two-thirds grasses and one-third legumes. Mixing different grasses and legumes can help a pasture produce longer during the year by staggering the growth peaks. You might have a mixture with cool-weather grasses for spring and fall, and warm-weather grasses to keep the pastures green and growing during the hot summer. Also, be careful with the species you mix because some plants are better at establishing themselves and can "take over" a field.
"Legumes are more aggressive in establishment than grasses are," says Lauriault. "If one plant is established, then it can spread out rhizomatously. Alfalfa can be a bulky plant from one seed. White clover is also rhizomatous--it can fill itself back in if other plants die." Most grasses (except fescue) can't grow rhizomatously--they can only grow one plant per seed--so they can't spread as quickly as the legumes. Legumes also tend to produce more foliage during summer months than the cool-weather grasses.
While having alfalfa in a field increases its productivity and nutrient level, you have to be careful when introducing a horse to that type of lush pasture. Prevent laminitis by letting him graze only a few hours at first, or by feeding him hay before turning him out.
Robison advises careful management of a field that's even 30% alfalfa. "It's such a high-quality forage that you have to manage it more closely than grass. Don't turn out a horse in that pasture with an empty belly."
One saving point is horses are selective grazers. Your horses might eat grass first, anyway. "Those legumes don't taste as good fresh (as grasses), but when baled, a horse will eat the alfalfa first," Lauriault says.
That, too, can have a down side. "The horses will hit that grass over and over and over again," Bader says, "so you can end up with just an alfalfa field."
You can buy pre-mixed seeds for horse pastures, which defers decisions about how to blend seed varieties. Robison named timothy, orchardgrass, ryegrass, bluegrass, festolium, and endophyte-free tall fescue as preferred grasses for horses.
Where's the Good Stuff?
The leaf blade is the most nutritional part of a grass, but it is low in fiber and high in protein; the stems are high in fiber. You might want to get an analysis of the nutrient value of your pastures to help you determine your overall feeding program. To gather a sample of pasture grass to test the nutrient value, "Hand grab samples from different parts of your pasture, or from different types of mixes in different pastures," says Robison. "Grab after the grass is up eight to 10 inches tall, or if horses are grazing it, above a one-inch minimum." He notes that a laboratory can give you information on a plant's protein, calcium, phosphorus, and potassium content. A list of labs certified to test forages by the National Forage Testing Association can be found at www.foragetesting.org.
You should also ask that your pasture be tested for fiber content and digestibility. Fiber is the most important component of a horse's diet, and also helps maintain gut health. For more information on fiber, see "Fiber Facts" in the December 1997 issue of The Horse, online at http://www.thehorse.com/ViewArticle.aspx?ID=600.
Bader says, "In most cases, the pasture--especially during the growing season--far exceeds the horse's requirements."
Plant Maintenance Tips
A soil test indicates what type of fertilizer you might need to apply. A "complete" fertilizer contains nitrogen, phosphorus, and potassium. Robison explains, "Since horse pastures consist mainly of grasses, nitrogen applications will be very helpful. Generally, it is best to apply up to 150 pounds of nitrogen per acre over three applications. For most regions, this means 50 pounds of nitrogen in early spring, again in late May or early June, and finally again in September."
Fertilizing grass in late fall can stimulate tillering, which is where the plant throws off shoots, says Robison. "Fertilizing in late fall helps to promote much more leaf growth."
You can also renew plant growth through annual seeding. Seed warm-season plants in the spring, and cool-season plants either in the spring or fall. Overseed yearly in spring or fall by spreading seed on top of the ground. You can "scratch" the surface to help seeds germinate at a slight depth. Robison advises, "Use a harrow, not a disc. You can use a no-till drill or fine-tooth harrow just to scratch the surface."
Another approach is to frost seed, or spread seed on frozen ground in late February or early March. Early spring's cold and wet weather helps certain seeds germinate. Recommended varieties for this type of seeding include ryegrass, festolium, clovers, and orchardgrass.
Seed at a high rate (lots of seeds per acre), because a thick stand of plants can fend off weeds better than a thin one. Weeds reduce the quality of the forage, and a weed invasion can weaken the desirable plants.
"A good offense is a good defense," says Robison. "Weeds do better in unfertilized soil, and they handle unnourished ground better than grasses will."
If necessary, you can spot-spray weeds with a herbicide targeted for the species and your region. Robison cautions, "Read all the label directions explicitly. Read how long to leave horses off the field." Avoid using lawn care products on pastures, he adds.
Remember to also keep animals out of the field when seedlings are growing and allow new plants a six-week start before allowing animals to graze on them. Otherwise, the plants don't get well established and the horses will destroy them (and all your pasture maintenance efforts to date).
Plan your irrigation methods depending on your plant species, climate, and rainfall patterns. "Schedule your water so it's most beneficial, when the plants are young," Lauriault recommends.
He adds, "If your ground and your grass look dry, water the pasture. If your plants have a blue-gray cast on them, they need water." Horses can churn up muddy ground, destroying the plants, so keep them out of a water-soaked field.
You should also check your pastures and anything your horses can reach from inside them for plants that are poisonous to horses. See "Poisonous Plants" in the May 2001 issue of The Horse for more information, online at http://www.thehorse.com/ViewArticle.aspx?ID=3058.
Control Horse Effects
Horses graze to eat, so you naturally expect to see the grass clipped short. They selectively graze about 14 out of 24 hours, and can be harder on pasture than cattle.
"Horses graze a lot closer than cattle," says Lauriault. Bader agrees, describing how the horse attacks a plant: "He pulls a grass plant. He doesn't make as clean a cut with his teeth--he tears the plant up."
To preserve your planting, tour your pasture and ask yourself these questions:
Where do horses graze the most? Do you see high and low spots?
As selective grazers, horses overgraze certain areas and undergraze others. They also select areas to defecate separate from their grazing areas, if there is enough land available. Lauriault advises not letting your grass get lower than two inches.
"If you go lower with a cool-season grass like fescue, you will open up the stand and weeds will come in. The fescue will die. But you can graze alfalfa down to ground level, and it will recover."
Correct undergrazing by clipping or mowing the pasture. This practice can increase density, quality, and taste of the plants. Clip the tops of grasses to a height of two to four inches before the grass "heads" (matures); this encourages the plant to re-establish its former leaf surface area.
Extend productivity by rotational grazing, or limiting grazing time in each area so the grass can regrow its leaves. You can do this by dividing your pasture into paddocks sized for the number of horses you have. "Get your paddock size small," says Lauriault. "Leave the horses on it two or three days to spot graze all over, then move them out. Give the pasture four to five days rest so it has a chance to recover."
When you move horses off a paddock, you might need to fertilize or even irrigate. When you fertilize a pasture, keep the horse off the field at least three days, or as long as three weeks depending on the product.
Robison explains what he sees as major mistakes: "People don't feed the pastures, and they don't rotate out of their pastures. These plants are living organisms. We wouldn't dream of going hours without eating, yet we expect pasture to go for years without being fed."
Also, horses can introduce parasites to a field. Keep them on a regular deworming program and spread manure with a chain harrow. Breaking up manure piles helps dry them out and kill some parasite eggs and larvae, but only when done in dry weather, whether hot or cold. Spreading manure in warm, moist weather encourages parasites to hatch and thrive. Removing manure is better, if it's possible.
For more information on parasites, pastures, and manure management, see "Parasite Primer" in the May 2001 issue of The Horse, online at http://www.thehorse.com/ViewArticle.aspx?ID=246; and "Manure Management" in the October 1997 issue of The Horse, online at http://www.thehorse.com/ViewArticle.aspx?ID=641.
Where are the high-traffic areas?
Water and oxygen need to penetrate the ground so plants grow deeper roots. Work the packed soil in high-traffic areas such as those near gates, water troughs, feeding areas, etc., to aerate it and introduce more oxygen. You also should plan to use plants that withstand high traffic, such as endophyte-free fescue.
Take good care of your pasture, and it will take good care of your horses.
About the Author
Award-winning writer Charlene Strickland lives in Bosque Farms, N.M. She has published 8 books and over 600 magazine articles, and is a member of the International Alliance of Equestrian Journalists.
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