Five Steps to a Great Horse Pasture

(Conservation Currents, Northern Virginia Soil and Water Conservation District, October 2004)

Great horse pastures provide grazing throughout most of the year, suppress weeds, and are aesthetically pleasing even through the eyes of a non-horse keeping neighbor. You almost can guarantee that the grass will be green on your side of the fence by planning and implementing proven techniques known as Best Management Practices (BMPs). These BMPs include:

1. Soil testing, fertilizing and liming
2. Over-seeding and renovating bare spots
3. Establishing/maintaining a sacrifice area
4. Controlling grazing pattern
5. Controlling weeds

1. Soil Testing, Fertilizing and Liming

If your pastures have not been tested for nutrient levels within the last 2-3 years, now is a good time to do it. Obtain sample boxes and a soil sample information sheet from your local library or the Northern Virginia Soil and Water Conservation District office. For $7 per sample, the Virginia Tech Soil Testing Laboratory will perform the analysis, send you the results, and recommend quantities of fertilizer and lime needed to produce maximum pasture yield.

Follow the recommendations for fertilizer application and repeat yearly. While fertilization can be done at any time of the year, you will realize maximum benefit if you fertilize cool season grasses in the fall. This is when most weeds die back, and grasses are dormant in their “above ground” growth. During this period, applied nutrients help root systems develop into more mature organs, capable of penetrating deep into the soil. A well-developed root system can extract water from greater depths, especially during the summer drought spells.

In early spring, you can boost the leafy growth of your pastures by adding 50 pounds of nitrogen per acre, as long as your pasture does not consist of legumes, such as clovers.

Applying the correct amount of fertilizer does not guarantee a healthy pasture if the pH level is too low. In low pH (acidic) conditions, plant nutrients are chemically bound and unavailable for absorption by cool season grass roots. A soil pH of 6.2 is the ideal condition in which pasture grasses can readily absorb their much-needed nutrients. A higher pH level than 6.2 does not improve pasture yield.

Unlike fertilizers, agricultural lime does not readily dissolve to become a part of the soil chemistry. Therefore, if the recommended lime application is greater than 2 tons/acre, you can avoid waste by splitting the applications (6 – 9 months apart) unless you can disk the whole amount into the soil. This is possible if you are establishing a new pasture or replanting a deteriorated field back into pasture.

Lime applications are equally effective at any time of the time of the year. However, no more than the total recommended amount should be applied over a three year period. After three years, you will need to re-test the soil.

2. Over-seeding & Renovating Bare Spots

Over-seeding replenishes the stand of grass within an existing pasture area. For pastures with cool season grass mix, it is best to over-seed during the late summer or early fall. To ensure good seed-soil contact, use a drill seeder. If you don’t have a drill seeder, hand-broadcast the seeds or use a seed spreader, and then spread a thin layer of composted manure one-half to one-quarter inch over the seeded area to create improved seed-soil contact.

Usually over-seeding requires minimal soil preparation, unless the process is combined with pasture renovation. Pasture renovation includes filling depressions and eroding areas with topsoil (not composted material), and then seeding.

Pasture renovation commonly includes restoring grass cover in high traffic areas, such as along fences and around gates. Use temporary fencing to keep the horses out of the area during renovation until the new grass is well established. The area must be disked, graded and reseeded. Consider hardy grass species, such as tall fescue, when reseeding high traffic areas.

Reestablishing a pasture area that has turned into a dirt or weed field is also considered pasture renovation, but more extensive soil preparation is necessary; fertilizing, liming and seeding are the very least to be done. It is essential to keep the soil moist by watering and mulching with straw to keep the germinating seeds from dehydrating and dying.

NVSWCD recommends a seeding rate of 18–20 pounds per acre using high quality pasture seed mix. While legumes, such as clovers, enrich the soil with plant-available nitrogen, you should limit the mix to no more than 25% legumes to prevent horse drool.

Do not allow horses to graze the field for one full year after you have achieved growth in the renovated pasture area. Otherwise, your labor will be for naught. During the wait, consider cutting the grass for hay. If you cannot keep the field unused for an entire year, then renovate the area in sections, a year at a time.

3. Establishing/Maintaining Sacrifice Area

Sacrifice areas are key to successful pasture management, especially in situations where horses are kept in relatively small acreage. For one or two horses, a sacrifice area can be as little as a 350 sq. ft. (14’ X 25’) fenced in area. Horses can be kept within the sacrifice area and provided with hay and drinking water. Here, they can “horse around” and get their much-needed exercise with no harm to your pastures.

Sacrifice areas provide respite for pastures exposed to intense grazing. Even with opportunities to confine animals within certain fields while others recover, intensely used pastures are impossible to manage without the incorporation of a sacrifice area into the rotational system. Extreme weather conditions (such as drought and excessive rain) also create conditions that demand the use of a sacrifice area.

In a newly established pasture, keep the horses in the sacrifice area until after a year of growth. After a year, allow up to 50% of the available grass to be grazed. Then give the field a chance to recover, until re-growth is about six inches. Depending on the weather and soil conditions, the re-growth period may be one to three months.

Conditions necessary for a successful sacrifice area include:

• Proper drainage
  • Maintain a surface slope of about 3% to prevent erosion.
  • Establish good drainage at the time of construction or renovation. A standard design includes spreading a sheet of heavy duty geotextile in contact with the graded soil surface and a six-inch layer of crushed limestone rock consisting of particles sized at 3/4” to 3”median diameter on top of the geotextile. The layer of crushed limestone is then capped with 3” to 4” of fine cover material which can be ground lime stone, crusher run or mulch. Limestone has proved to be the best capping material.
  • Divert all offsite flows (such as barn runoff) around the area.
• Waste removal
  • Remove waste from the site on a daily basis or before rain.

4. Controlling Grazing Pattern

Once the pasture is established and rapidly growing, the next step is to control when, where, and for how long the animals graze. Achieve this easily by installing cross fences to separate the grazing area into smaller fields. By nature, horses like to bolt in long straights. Therefore, consider dividing your pasture into longer fields, rather than the traditional square fields. Always keep in mind that fields can be divided using temporary fences.

Horses do not need continuous grazing and feeding. Their dietary requirement can be met by just a few hours a day of grazing on a good stand of pasture and, if necessary, supplementary feed. Therefore, controlling the grazing pattern through shorter grazing periods and rotating the horses through the pastures will help the grass stay resilient and prevent weed growth.

Controlling grazing intensity and timing through a rotational system can also provide a longer grazing season. It provides an even distribution of manure throughout the fields, controls the possibility for horses to over-graze, and reduces erosion.

Fields should be rested as soon as the pasture has been grazed down to about 2–3 inches high. An unevenly grazed pasture should be mowed down to make for uniform re-growth. Dragging horse droppings on a regular basis helps prevent clusters of non-grazed vegetation within a field.

Keep animals out of water saturated pastures to prevent damage to the pasture and erosion.

5. Controlling weeds

Control weeds with a combination of techniques. Proper identification of weeds is key to determining the most effective herbicide, and the best time in their life cycle to be treated. Adequate (not excessive) fertilization and liming, and a controlled grazing practice create conditions for preferred vegetation to thrive over unwanted vegetation (weeds).

Other great weed control techniques include:

• Regular mowing of weeds especially before they get to seed production stage.
• Composting of horse manure to kill contained weed seeds.
• Using high quality seed mix that contains low percentage of weed seeds.

Obtain recommendations for using EPA approved herbicides for the control of specific weeds in pastures, as well as susceptibility table and grazing restrictions from the Virginia Cooperative Extension’s Pest Management Guide for Field Crops — Publication 456-016.

By implementing these best management practices, the site of your horse operation will not only be the envy of other horse keepers and a visual pleasure to non-horse keepers, it also will make great contributions toward protecting the environment through nonpoint source pollution reduction. You will have done your part in maintaining the integrity of our ponds, lakes, streams, and the Chesapeake Bay.

For more information about managing suburban horse operations, contact Willie Woode at 703-324-1430, TTY711 or send him an e-mail.