Year-Round Pasture Management

If you manage them properly, pastures are one of the most economical ways to feed your horses.

Ask any experienced farm owner or manager--proper pasture management definitely has its perks. Managing pastures properly prevents erosion and nutrient loss from the soil, which also helps improve stream and water quality. In addition, pastures can provide an excellent "free-choice" exercise plan for horses. But the most important role pastures play in horsekeeping is that the grasses they contain are some of the most economical feeds available.

Where to Start

One of the best places to begin examining your pasture management processes is by taking a walk around the fields. Such a walk provides an opportunity to evaluate topography and "ground cover," or amount of available forage. Regular walks can help you determine if there are areas where forages grow well, and areas where forages seem to have problems getting established. Conduct these walks periodically throughout the year, every two months, to evaluate changes throughout the seasons. It is also essential to determine how many acres of pasture you have, and how many acres are available per horse.

While hiking the fields it is also good to recognize what types of plants are growing. A variety of books and extension publications with excellent descriptions and photographs of forages can help you become familiar with these plants. A few examples include the book Southern Forages, 4th Edition, (Ball, Lacefield, and Hoveland, 2007) and the Forage Use and Identification Guide, found at the University of Kentucky Web site These two guides contain plants found across the United States, but extension Web sites for each state probably will provide better information for your specific area of the country.

There are also a variety of books and Web sites that can help with weed identification and will explain which are toxic to horses. Some recent publications from Michigan State University Extension provide excellent information on toxic ornamental and pasture plants and trees. These can be downloaded or ordered from

Once you identify the plants, it then becomes important to determine the amount of coverage of edible plants, inedible plants or weeds, and bare ground. These estimates can help when developing a pasture management plan. A relatively simple method of determining this can be found at the Rutgers University Web site This site gives information on estimating pasture acreage as well as determining pasture quality. A modified version of estimating pasture quality follows:

  1. Pick two random sites in a pasture;
  2. At the first site, lay 25 feet of measuring tape across the ground;
  3. Mark what you find at each 6-inch interval on a sheet of paper. The most basic marks could be "edible," "inedible/weed," or "bare ground." A more complex system could include the type of edible forage, such as bluegrass, white clover, orchardgrass, etc.; and
  4. Go to the second randomly selected site and repeat steps 2 and 3.

Once you complete this there should be 100 marks. Count how many of each type of mark (bare ground, weed, edible forage) was found and estimate percentage. For example, if there were 30 marks under "bare ground," the pasture would have 30% bare ground. You can use the percentages to determine initial management procedures. Commonly, 75% or more of desirable plant species indicates that no renovation is required, 40-75% desirable species indicates the need for improved management procedures and overseeding with desirable forages, and less than 40% desirable species indicates a complete pasture renovation is necessary.

Soil Testing and Fertilizing

Testing the soils in the pastures to determine nutrient availability is an important step in pasture management. A soil survey might be available for your area through the USDA's Natural Resources Conservation Service (NRCS). The Web site ( gives directions on how to use this free service. Information on this site will help you determine the best uses for the land based on soil type, drainage, and nutrient holding capacity (or permeability) of the soil.

Soil tests to determine lime and fertilizer needs of the different pastures should be performed at least every three years. There is much debate as to whether the fall or the spring is the best time to test, but what is most important is to test at the same time each year so direct comparisons can be made. There are a variety of guides available on how to take a soil sample, and these can be found at most university extension Web sites. For example, The Ohio State University's site is Many county extension offices or feed and farm supply stores have the equipment necessary to take soil samples, and they might be willing to loan or rent the equipment. These offices can also help you decide where to send the samples to be analyzed.

The cost of sample analysis depends on where you send the sample and for what you test. A basic analysis of nitrogen, phosphorous, potassium, and pH will cost between $10 and $20 per sample, possibly higher. It is also possible to purchase soil probes, which range in price from $50 to $150, and a basic home soil testing kit, which will test 15 samples, for between $20 and $50. The home testing kit results will not be as accurate as those from a commercial lab, but they can give you an idea of what is available in the soil.

Although soil testing might seem like an expensive endeavor, in the long run you will save money because you won't be purchasing unnecessary fertilizer and lime.

Divide pastures into sections based on soil type, use of the area, and visible differences in forage growth. For example, a low-lying area that receives nutrient runoff might have more lush pasture growth and different fertilizer requirements than the pasture located at the top of the hill. Recommendations are usually to take one sample per acre of field, but on large fields this might be daunting. Therefore, on large fields one sample should represent no more than 20 acres, and there should be a minimum of 10 samples and a maximum of 30 samples per field. It is also important to avoid taking samples in areas of obvious fecal and urine contamination, and to make sure all plant debris (leaves, stems, roots) are removed from the soil samples.

After the sample is analyzed you'll need someone to interpret the results and develop a fertilizing plan. Usually, the first result will be an analysis of pH and liming recommendations. Lime contains calcium or magnesium carbonates that help increase soil pH, which, in turn, helps improve plant absorption of other soil nutrients. Although horses can stay on the pastures when limestone is added, many people prefer to remove the horses from the pasture until a rainfall of around a half-inch removes the dust from the leaves and begins to dissolve the limestone. It will take about six months for the limestone to make a difference in soil pH, so a fall application is recommended in most areas.

The soil analysis results will also include recommendations for the application of fertilizers containing nitrogen, phosphorous, and potassium. Nitrogen helps the growth of pasture plants above the ground, and it is best to apply it either while growth is occurring or just before expected growth. In most areas an early spring application is recommended. Remove horses from the pastures before application and do not turn them back out on the treated pasture until adequate rainfall has removed the fertilizer from exposed plant parts and the nitrogen has leached into the soil. Generally, approximately a half-inch of rainfall is sufficient to dissolve granular fertilizer, but check pastures to make sure no fertilizer is still visible on the soil surface. Ideally, horses will not graze the pastures for at least two to three weeks after fertilizing.

The other two nutrients most commonly applied--phosphorus and potassium--are necessary for establishing a good plant root system and helping with plant tillering (developing offshoots from the original plants). If you need to apply these nutrients, you should do this prior to pasture growth or after the pasture has been either grazed or mowed to about 3 inches in height.

In areas of the country where there is a higher clay content or aluminum and iron oxides in the soil, the leaching of phos-phorus and potassium out of the soil is fairly negligible, but the soil is prone to lose both due to erosion. Therefore, there is not as much concern as to when you apply them to pastures, as long as both are available to the plants. It is important to make sure that phosphorous is adequate when root growth is desired, such as when establishing plants or when preparing for dormancy during the winter.

Forage Selection

Once you've assessed the pastures for forage coverage and checked the soil's fertility, you can make decisions about the need for other forages. Forage selection will depend on a variety of factors, including the region of the country, soil type, pasture use, and number of horses per acre. You can use the books and articles recommended previously to make decisions on what else could be planted. In addition, local extension specialists and farm supply store employees can help you make informed decisions.

Although a mixture of forages is usually desirable, it is best to keep the combination as simple as possible to make management easier. Ideally the mix will contain some grasses and legumes, and cool-season and warm-season forages. This mix will prolong grazing for almost the entire year, including periods of low rainfall and high temperatures. Time of seeding varies, depending on the type of forage you're planting and location, but usually seeding is done during the spring or fall. Soil temperature, soil moisture, and timing of first and last frost will affect optimum seeding time, but the more time the plants have to mature, the better their establishment and longevity.

Whether or not you turn out your horses on the pasture you're seeding will depend on a variety of factors, including seeding method, whether or not the pasture is being completely renovated or overseeded, and available ground cover to protect the new seedlings. On pastures where a complete renovation is required, keep horses off pastures for at least six months, if not a full year. Horses might be able to stay on pastures where you are enhancing the types of available forages with the addition of new seed.

Take-Home Message

Proper pasture management is an essential part of farm management. The benefits of a well-maintained field will outweigh the time and minimal costs associated. There are a variety of extension resources available; develop a working relationship with your local and state extension specialists, who will impart their knowledge, helping you raise better pastures.

About the Author

Janice L. Holland, PhD, PAS

Janice L. Holland, PhD, PAS is an associate professor of Equine Studies at Midway College in Midway, KY. Her main academic interests are equine nutrition, pasture management, and behavior.

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