Contents
- What do you want from your farm?
- Poor conditions on horse farms affect animals, people and wildlife
- What makes horses different?
- Seven steps to a safe, efficient, environmentally friendly horse farm
- Step 1. Don’t overgraze your pasture
- Step 2. Manage your pasture for optimal grass growth
- Step 3. Use buffer strips to protect water
- Step 4. Manage manure and bedding resources
- Step 5. Manage weeds to protect your horses
- Step 6. Install rain gutters and downspouts
- Step 7. Protect your household water supply
- For more information
What do you want from your farm?
Goals for a well-managed, small-acreage horse farm are:
- A productive pasture with plenty of grass and few weeds.
- Less dust during the dry season and less mud during the wet season.
- Healthy horses free of problems associated with dust, manure, mud and toxic plants.
- Manure managed as an important resource on the farm or recycled off the farm.
- Good stewardship of your property and the water that flows through, across and below it.
- Satisfied owners who conveniently care for their animals without dreading the chore.
The key to meeting these goals is to recognize that horses, grass, manure, soil and water are interconnected. How you manage one affects the others. When, where and how long your animals graze affects grass regrowth, weed competition and the safety of your well water. How you deal with water runoff affects your horse’s health, nearby streams and your own enjoyment of the property. By properly managing each aspect of your farm, you will have greener pastures, healthy horses and more personal satisfaction.
Poor conditions on horse farms affect animals, people and wildlife
Living in dust, manure, mud, weeds or a combination of these is unhealthy. Dusty conditions lead to respiratory diseases. Dust carries irritating particles, pathogenic bacteria and viruses into the lungs. A horse living in dusty conditions is more inclined to respiratory infection. In addition, a horse suffering from a respiratory infection takes longer to recover in dusty conditions than in dust-free air.
Overgrazed pastures with little grass cover can be a source of sand colic — a serious digestive disorder that occurs when horses fed on bare ground ingest soil and sand. In addition, horses on overgrazed pastures are exposed to manure while eating and are at a higher risk for internal parasite infestations. Horses routinely left on overgrazed pastures reinfest themselves and spread internal parasites to other horses in the herd.
Although the intensity and length of the mud season vary east of the Cascades, mud can be a problem for small-acreage horse farms. Mud harbors bacteria and fungi that cause health problems. Wet conditions soften the hoof and sole, causing cracking and splitting. Horses become susceptible to stone bruising, abscesses and thrush, an infection of the frog of the hoof. Wet, muddy conditions create slick, unsafe footing that can result in injuries.
Cold, wet, muddy conditions can lower a horse’s body temperature and may even cause hypothermia. Animals kept in these conditions burn significantly more calories just to keep warm, and will require more feed.
Weeds easily infest overgrazed pastures. While most are harmless, some can be dangerous to horses, and most are unsightly. Weeds indicate a management problem and reduce the value of the pasture as a source of feed.
Poor conditions on horse farms lead to pollution of well water, nearby creeks and other surface water. Nitrate and bacteria from manure and urine run into creeks and groundwater, affecting the quality of your drinking water as well as that of your neighbors and your animals. These pollutants, as well as excess phosphorus and topsoil runoff, threaten fish and other wildlife that depend on the creeks, rivers and lakes of Central and Eastern Oregon.
This publication presents a system for managing horses, pastures and manure that will make your farm safe, efficient and environmentally friendly. It is intended for horse farms ranging from 1 to 10 acres in the high, dry regions of Eastern and Central Oregon.
Because small-acreage owners lack the space of larger farms and ranches, they are confronted with a unique set of challenges. We’ve tailored our recommendations for small farms, but they can be adapted to larger farms as well. Options for low-cost and higher-cost approaches for irrigated and nonirrigated operations are included.
This publication is a place to start. Contact your local OSU Extension office or consult the resources listed at the end of this publication for more in-depth information.
What makes horses different?
Horses are adapted to and once roamed immense, arid grasslands. Living like this, they stay in one area for only a short time and have little impact on the environment. When we keep horses on small acreages, we must use management practices to minimize their impact.
Most horse owners know that horses are different from other livestock in their behavior, and in how and what they eat. Our reasons for owning horses are often different, too.
Activity level
Horses are heavy animals with big, often steel-shod, hooves. Unlike other livestock, they can be very active, and they enjoy running and playing. In contrast, mature cattle tend to eat, lie down while they digest their meal, and make an occasional trip to the water trough.
Horse owners take pleasure in watching their animals run, play, and “kick up their heels.” Too much of this activity concentrated on small acreage can severely damage pastures. The horse’s natural way of running and its flipping hoof action damage forage by cutting off or uprooting whole plants.
Eating habits
Unlike sheep and cattle, horses have both upper and lower teeth. They also have very active lips. With a short tongue and a sensitive, strong upper lip, horses bring food to their front teeth and then bite. As a result, they are very efficient grazers — sometimes too efficient. Horses have the ability to quickly eat grasses right to the soil surface. When this happens too often, it kills the grass.
Although horses will eat broadleaf plants, brush or trees, they have a stronger preference for grass than do cattle or sheep. They prefer short, tender grass over longer, coarser grass.
Horses are top-grazers. They bite off the tops of preferred plants until that pasture is grazed short. They continue to graze regrowth on the preferred plant and avoid what seems to be good, taller pasture. Horses prefer the base of the grass stem, which has significantly higher sugar and carbohydrate content than the upper parts of the plant.
Horses continue to graze on the regrowth of their preferred plant and avoid what appears to be good, taller pasture. This grazing style results in overgrazed pastures. Overgrazed pastures lead to weed infestations, increased internal parasite loads, and the need for costly pasture renovation or higher hay costs.
Horses are "recreational grazers" and will continue to graze after they have met their nutritional requirements. Table 1 compares the activities of horses, cattle and sheep on pastures. If unmanaged, horses will spend over half the day eating.
|
Horses |
Cattle |
Sheep |
|
|---|---|---|---|
|
Grazing |
14 | 9 | 9 |
|
Standing |
8 | 4 | 3 |
|
Lying down |
1 | 9 | 11 |
Source: A Production Guide for Coastal British Columbia and the Pacific Northwest.
Seven steps to a safe, efficient, environmentally friendly horse farm
The problems noted in “Poor conditions on horse farms affect animals, people and wildlife” are common on small-acreage horse farms. The grazing habits and activity of horses can lead to overgrazed pastures. The techniques discussed in this publication will reduce this damage. Follow these seven steps to improve your farm:
- Don’t overgraze your pasture.
- Manage your pasture for optimal grass growth.
- Use buffer strips to protect water.
- Manage manure and bedding resources.
- Manage weeds to protect your horses.
- Install rain gutters and downspouts.
- Protect your household water supply.
Together, these management practices will promote a well-managed, sustainable farm that cycles nutrients, protects soil and improves water quality, while providing an attractive, efficient environment for horses and people.
Remember that agricultural activities are not allowed to pollute water. You must prevent animal waste from polluting streams and irrigation canals. You also must allow vegetation along streams to provide shade, stabilize banks and filter potential pollutants from overland flows.
Step 1. Don’t overgraze your pasture
Many pastures in Central and Eastern Oregon are overgrazed. Repeated heavy grazing removes too much of the plants’ leaves, weakens the root structure and slows regrowth. As a result, less forage is available for grazing, and pastures are vulnerable to weed invasion, dusty or muddy conditions, and soil erosion.
In contrast, a well-managed pasture with good ground cover provides abundant forage, space for recreation, strong competition against weeds and protection from water quality problems and other negative environmental consequences. These benefits are achieved through good grazing management and by regulating the amount of time horses spend on pastures. The best way to protect against overgrazing on a small acreage is to make a dry lot a key part of your grazing strategy.
The dry lot
A dry lot is one of the best management tools to maintain pasture condition. A dry lot, or paddock, is a small enclosure, such as a corral, pen or run, that serves as the horse’s outdoor living quarters when they should not or cannot be on the pasture. This area holds horses and prevents overgrazing when grass is in short supply, prevents damage to the pasture when it is too wet or too dry and allows owners to control the amount of grass horses consume. A dry lot is also useful for separating or confining animals.
Options for dry lots
Without additional footing material, a dry lot is often referred to as a “sacrifice area.” These are small areas sacrificed to benefit the remainder of the pasture. Sacrifice areas get overgrazed and become dusty or muddy, depending on the season, but they protect the rest of the property from the same fate. This approach is very low cost.
A dry lot can be more than a confinement area for horses when they are not on pasture. These areas can be designed for multiple uses and might include, for example, a run from a horse stall, a small outdoor arena or a round pen.
Adding footing to a dry lot keeps it drier during the wet season and dust-free during the dry season. Common footings include stall mats, gravel, sand and coarse, shredded wood products. Available materials vary by region, but the best materials maintain good drainage without compacting, while providing stability for the intended activities. The goal is to have a safe, well-drained, all-weather surface.
Gravel drains well and provides a solid, level surface. Select an aggregate size that won’t contribute to stone bruising on the feet, such as 3/4- or 5/8-minus.
Sand drains well and can provide a surface for working horses. It should be coarse and clean and contain very little fine-textured silt and clay. If horses are fed on the ground, however, sand colic can be a concern.
Shredded wood, which is sometimes called “hogged fuel,” might be available in areas with timber resources. It provides a forgiving surface and reduces urine smells, but it makes manure picking more difficult and must be renewed every year or two.
When choosing a footing material, ask yourself the following questions:
- Is the dry lot only for standing, or is it also for working?
- What footing materials are available locally?
- What are your preferences for footing?
Establishing and maintaining a dry lot
A well-sited dry lot makes it easy to care for your horses and maintain the area. Choose the location of your dry lot carefully. Locate it:
- On higher or well-drained ground
- Away from your domestic wellhead or other water sources
- Close to the barn or other shelter
The dry lot should be sized to fit your farm and the number, size and personalities of the horses to be confined. It should offer no less than 256 square feet (the equivalent of a 16-by-16-foot stall) per horse. A dry lot of this size does not provide space for exercise, however, and many horse owners prefer a much larger area.
Fences for dry lots should be strong, secure and safe. Gates must be at least as wide as the equipment you will use to haul footing materials or to clean the pens. Fence height for dry lots is extremely important because horses can reach over the best of fences. A good rule of thumb is to place the top rail at withers height — about 5 feet for most horses. Consider the depth of footing material and its accumulation over time when installing fence posts and planning fence height. Horses have poor eyesight, so high visibility is another consideration when planning a dry lot fence.
Traditional wooden fences are an excellent option, although bored horses may chew wood. Prefabricated metal fence panels designed for use with horses are a good material if horses are confined for long periods. Many brands are available, and they are economical when one considers their long life. Wire fencing material such as “V-mesh” is relatively inexpensive and safe for horses. If an electrified wire is used along the top rail, choose wide electric tape for better visibility and safety compared to smooth wire. Barbed wire should never be used for horses, as it poses a high risk of serious injury.
It is important to minimize water runoff from the dry lot. Install rain gutters on buildings to divert clean water away from the dry lot (see “Install rain gutters and downspouts”). In addition, buffer strips between a dry lot and nearby creeks contribute to high-quality surface water (see “Use buffer strips to protect water”).
Trees can provide shade and protection from the wind. They also add habitat for wildlife and enhance the aesthetics of your farm. Trees growing inside the dry lot should be protected from chewing, girdling and soil compaction. It’s best to fence along the drip line (the area under the branches) to keep horses away from the trees. At the very least, protect trees from girdling by caging the trunks with wire mesh. This method will not, however, protect the roots from compaction. Consider planting new trees beyond the reach of horses, for example, outside the fence lines.
To reduce parasites and flies, pick manure regularly. Regular picking keeps the paddock footing clean. When handled properly, horse manure composts well and can play a role in nutrient management for pastures (see “Manage manure and bedding resources”).
Step 2. Manage your pasture for optimal grass growth
Because the size of a small-acreage horse pasture is limited, its primary purpose is to provide a productive cover of grass, free of weeds and bare spots. Meeting the horses’ nutritional needs is often secondary. Nutritional needs can be met by hay or by a combination of hay and grain. The small-acreage pasture only provides supplemental feed and space for recreation.
Planning for pasture management
The following tips can promote sustainable horse-keeping in dry-climate areas:
- Understand how and when grasses and other forages grow and how much your horse should eat.
- Manage grazing to maintain vigorous growth and long-term stands of desired pasture plants.
- Select the right pasture plants for your climate, water supply and soil conditions.
- Manage pasture fertility to promote strong stands of grasses and other forages.
- Use irrigation water efficiently.
Each of these topics is discussed below.
Understand how and when grasses and other forages grow and how much your horse should eat
How grass grows
The long-term health of forage plants requires three things:
- Enough leaf area and sunlight for photosynthesis
- Intact plant growing points for quick regrowth following grazing
- Roots sufficient to support the leaves and stems of the plant
Plants manufacture food in their leaves using solar energy, carbon dioxide from the air and water to make sugars and complex carbohydrates. This process, called photosynthesis, requires “solar receptors” in the form of green leaves. Removing too many leaves through overgrazing slows plant growth and limits the root system.
Figure 1 illustrates the growing points of forage plants. One growing point called the apical meristem is located at the base of the plant. Over the course of the spring, this growing point rises above the ground and develops into the seedhead.
When growing points are grazed off, those shoots are unable to regrow, and new growth will originate from a new set of growing points. All plants are susceptible to overgrazing — some more than others.
Pasture plants store sugars and other carbohydrates to survive the winter. This stored food allows them to begin growing again the following spring. Good management during the fall is critical, as roots and the crown stockpile nutrients for the spring growth. Schedule the final grazing to leave enough time for plants to regrow before winter dormancy. Leave plants no shorter than 3 inches. This practice ensures a supply of growth buds for next year and a reservoir of energy for a good start in the spring.
To learn more about how to improve your pasture management based on understanding principles of growth and regrowth, visit Oregon State University’s Forage Information System, Match Forage, and Inland Pacific Northwest pasture calendar, PNW 708.
When grass grows
If pastures produced evenly throughout the year, feeding a horse would be easy. The reality is that pasture grass and legume plants are seasonal in their production. Typically, irrigated pastures in Central and Eastern Oregon grow quickly during the spring, slow their growth during summer and increase growth slightly again in the fall.
Figure 2 shows the seasonal irrigated pasture growth for Central Oregon under optimal and average management. Optimal management includes managing soil fertility, grazing and irrigation so pastures produce at a very high level. Average management is closer to the common practice. Note the amount of feed needed per horse per day. Under average management, more than 1 acre is required to feed a horse during most of the grazing season. Typical growth patterns vary by elevation, latitude, soil fertility, plant species and average rainfall.
This natural growth cycle can provide too much feed at some times and not enough at other times. Some farms use some of their pasture to produce hay that is stored and fed when the pastures are not producing. Small-acreage horse farms may not have this option.
How much your horse should eat
The equine digestive system requires forages for normal functioning, and forage requirements are easily supplied by pasture and hay. Horses do not have a multicompartmental stomach as cattle, sheep and goats do. Instead, the horse has a simple stomach that works much like a human’s. Horses do not effectively digest low-quality forages; hence higher quality, more digestible forages are necessary.
Mature horses performing minimal work can be maintained on good-quality forages without supplementing their diet with grain. Growing, breeding or working horses may require grain or other concentrates to meet their nutrient needs. For optimal horse health, growth and development, forages should supply at least one-half of the calories consumed daily.
Horses consume about 2% of their body weight per day in feed. This amount is based on a dry-weight basis, so it accounts for the different amounts of moisture in different types of feed. Fresh grass, for example, is about 80% water, and grass hay is 10%–15% water. Thus, a 1,200-pound horse requires 24 pounds of feed per day on a dry-weight basis, or about 28 pounds of hay (10% moisture). Over the course of a year, this equals more than 5 tons.
Well-managed pastures can supply much of the forage feed requirement, depending on the size of the pasture, the number of horses and the length of the growing season. In Central and Eastern Oregon, well-managed, irrigated pasture can produce as much as 6,000–12,000 pounds (3–6 tons) of forage per acre per year. But note that if all the forage produced in a year were consumed, then the desirable forages in the pasture could not persist. See the section below on grazing management and target grazing height.
The majority of pasture forage is produced in summer (Figure 2). Supplemental feed will be required during other parts of the year.
If irrigated pasture is used as a major feed source, a mature 1,200-pound horse generally needs about 2 acres of pasture. New owners or managers can provide a safety buffer by doubling this estimate and carefully monitoring pasture conditions, feed supply and horse body condition.
Manage grazing to maintain vigorous growth and long-term stands of desired pasture plants
The first principle of good grazing management is never to graze the grass too short. The optimum height for most pasture grasses in Central and Eastern Oregon is between 3 and 8 inches. The ideal height varies depending on the species and whether the pasture is irrigated or dryland. The minimum height should never be less than 3 inches.
When grasses are between 3 and 8 inches tall, they are in what is called the “vegetative” stage because the grass is very leafy. At this stage, the grass is high in nutrients and competes well against with weeds.
Grass that is grazed too short is weakened, takes a long time to regrow and is susceptible to competition from weeds. Overgrazing is grazing too short and too often. Allowing horses to graze grass shorter than 3 inches also increases the chance that they will become infected by parasites because the majority of parasite larvae found on forage plants live on the lower part of the grass plant.
A dry lot is an essential part of pasture management on small-acreage horse farms. The dry lot is a comfortable, safe place for your horses when access to the pasture is restricted. Consider the dry lot or paddock the horse’s living room and bedroom and the pasture its dining room.
The three grazing strategies discussed below fit well with the use of a dry lot and are good options for small-acreage horse operations. The best option for your farm will depend on your goals and whether your farm is irrigated or dryland. These approaches vary in their ability to maintain pasture cover and reduce the risk of overgrazing. The proper choice involves balancing effectiveness against your management time, expense and expertise.
Partial-season grazing
Partial-season grazing limits pasture access to the season when the pasture is productive. Some horse owners graze their pastures during spring and early summer, when plant growth is rapid and forage quality is at its peak. When forage has been grazed to the proper height, horses are moved off the pasture into the dry lot and provided supplemental feed. In many areas, horses are not returned to the pasture until the following spring.
This approach is the best way to maintain dryland pastures that otherwise would become severely overgrazed during the dry season. During the grazing season, dryland pastures can be managed using “limited turnout” or “rotational grazing,” as discussed in the next sections.
Limited turnout
Limited turnout allows horses daily access to pasture for very short periods. With this approach, horses spend most of their time in the dry lot with daily turnout periods of an hour or two. This strategy works well on small acreages, particularly with pastures that cannot support longer grazing periods. It also can help maintain horses in proper body condition. Turn out to pasture provides exercise and may save money on feed costs by substituting pasture for hay and grain.
Rotational grazing
Rotational grazing is the most effective approach to grazing management. This approach divides the pasture into several smaller pastures or “cells.” Horses are allowed access to only one cell at a time.
While horses graze one cell, the grass in the other cells regrows. When forage height has been reduced to 3–4 inches, horses are rotated into the next cell. The previously grazed cell is rested until forage plants recover. Horses are not allowed to regraze a cell until plants have regrown to 6–8 inches. Horses can be returned for more grazing after sufficient regrowth occurs (6–8 inches).
On irrigated pastures, regrowth may take two to eight weeks, depending on the season. On dryland pastures, each cell is likely to be grazed only once a year.
If all cells have been grazed and none has regrown to 6–8 inches, horses are kept in the dry lot until there is sufficient regrowth to allow grazing. With this system, the dry lot also can be used at times to restrict grazing in order to maintain horses in proper body condition. A good rule of thumb is to graze half the height of the grass and leave half, especially if pastures are dryland.
The size and number of cells in a rotational grazing system depend on available acreage, number of horses, productivity of the pasture, availability of livestock water and how long horses will remain in each cell. Ideally, each cell should contain enough forage to sustain grazing horses for three to five days. Your situation may differ.
Plants begin to regrow after three to five days, and horses will overgraze the lush new growth, leaving other grass to become tall and rank. Longer grazing periods also increase damage from hooves, particularly near water and salt sources.
When first implementing rotational grazing, experiment with the size and number of cells. Be flexible! Avoid a strict calendar of entrance and exit dates. Instead, monitor the pasture condition. When the forage has reached the target height, remove horses to another cell or to the dry lot or paddock.
Horses tend to spot-graze (overgrazing some areas while not grazing others). Keep this in mind as you decide when to move them to the next pasture. Mowing between turnouts or at regular intervals during the grazing season will clean up pastures and restore the plant cover to a uniform height. In areas with significant snowfall, mowing can be deferred until after snowmelt. Stubble helps catch snow and prevent it from being blown away.
With all these approaches to grazing management, the dry lot is an integral part of the system when pastures are not suitable for grazing.
Winter pasture management
Frozen or snow-covered pastures are less subject to damage from the activity of heavy animals. Grass and other forage plants are dormant under these conditions. Snow-covered pastures provide the most protection to grasses. Frozen pastures reduce soil compaction but expose dormant pasture plants to grazing. Bored horses may graze exposed dormant plants below their growing points, potentially damaging the roots. Although not nutritious, dormant plants satisfy the animal’s desire to chew.
During winter, you can promote pasture condition by limiting turn-out time to one or two hours a day. Monitor the activity of your animals and the condition of forage plants during winter turnout times.
Select the right pasture plants for your climate, water supply and soil conditions
Select pasture plants based on whether you can irrigate your pasture and whether the pasture will be used primarily as an exercise area or for grazing, haying or both. The Oregon State University Extension Service, Natural Resources Conservation Service, Soil and Water Conservation District and local seed dealers can help you select appropriate grasses. See also Match Forage, a forage selection tool based on latitude, altitude, water, management intensity and intended use.
Pasture grasses may be used alone, in mixtures or mixed with a legume. Pasture mixes with more than one grass can work well. Keep in mind that different forage species grow at different rates and times. Mixed forage can extend the grazing period but also results in palatability differences, causing overgrazing of one grass and undergrazing of others. In this case, mow the pasture between grazing events.
The addition of 1–2 pounds per acre of white clover to the seed mix will provide nitrogen to irrigated pastures through nitrogen fixation and will improve the quality and quantity of forage during the hot season when grasses do not perform as well as legumes.
Forage species for dryland pastures
Because nonirrigated pastures in Central and Eastern Oregon depend on snow melt or rain to grow, their growing season is much shorter and their potential use by horses is limited to a few months per year. For dryland pastures, choose forage species based on average annual precipitation. See Table 2 or the MatchForage species selection tool.
Nonirrigated pastures benefit from mixtures of three to five species. Leaving 5–6 inches of stubble on dryland pastures and keeping horses off the pasture as they become dormant promotes strong regrowth the following spring.
Table 2. Forage species for dryland pastures
Annual precipitation levels less than 9 inches
- Crested wheatgrass
- Russian wildrye
- Siberian wheatgrass
- Thickspike wheatgrass
9–11 inches
- Crested wheatgrass
- Russian wildrye
- Siberian wheatgrass
- Thickspike wheatgrass
- Beardless wheatgrass
- Big bluegrass
12–14 inches
- Crested wheatgrass
- Russian wildrye
- Siberian wheatgrass
- Thickspike wheatgrass
- Beardless wheatgrass
- Big bluegrass
- Alfalfa
- Canada wildrye
- Hard fescue
- Idaho fescue
- Western wheatgrass
- Sainfoin
15–17 inches
- Crested wheatgrass
- Russian wildrye
- Siberian wheatgrass
- Thickspike wheatgrass
- Beardless wheatgrass
- Big bluegrass
- Alfalfa
- Canada wildrye
- Hard fescue
- Idaho fescue
- Western wheatgrass
- Sainfoin
- Intermediate wheatgrass
- Meadow bromegrass
- Pubescent wheatgrass
- Smooth bromegrass
Forage species for irrigated pastures
Irrigated pastures offer a longer growing season and a longer period of use by horses. See Table 3 or the MatchForage species selection tool.
Grasses that can survive heavy use, such as tall fescue, are best for exercise areas. Kentucky bluegrass alone or mixed with tall fescue will also stand up to heavy use. Options for grazing only or for grazing and hay include orchardgrass, Kentucky bluegrass (alone or with white clover) and tall fescue.
Manage pasture fertility to promote strong stands of grasses and other forages
Like horses, pasture plants need nutrients in adequate and balanced amounts. Fertilizing pastures promotes strong stands of desirable pasture plants, which are better able to compete with weeds. Fertilization also boosts grass production.
Nitrogen, phosphorus, potassium, sulfur and calcium are the nutrients typically added as fertilizer. Nutrients may come from synthetic or organic sources. Manure and composted manure can provide many needed plant nutrients, including nitrogen, sulfur, phosphorus and potassium, while improving soil biological activity and tilth. (See “Manage manure and bedding”.)
A soil test is the best way to determine whether fertilization will benefit pasture species, and at the rate fertilizers should be applied. Soil test results typically are good for two to three years; after that, retest. If results indicate that nutrients are deficient, test every one or two years. See Get actionable results from a soil, plant or environmental testing lab (EM 8677), Soil test interpretation guide (EC 628), Soil testing lab selection and recommended analytical methods for Oregon, EM 9423 and more related content.
Apply phosphorus, potassium and lime according to recommendations based on soil test results. In addition, 20–30 pounds sulfur per acre per year or 40–50 pounds of sulfur per acre every two years is recommended for irrigated pastures.
Apply nitrogen based on the need for higher or lower levels of pasture production (See “Nitrogen fertilization practices”). Monitor the results after fertilizing pastures. The level of pasture production should correspond to your farm’s feed needs and should be based on the number of animals and their nutritional requirements.
Do not overapply any fertilizer. Overapplication wastes money and increases the possibility of water contamination. In addition, high nitrogen and potassium applications can harm horses, especially during dry years. Forage crops can take up more potassium than required for optimum growth.
Nitrogen fertilization for irrigated pastures
Multiple applications of nitrogen throughout the growing season will result in more even pasture production and reduced potential for nitrogen loss as compared to a single, larger application. When clover or other legumes make up a meaningful proportion of the pasture (greater than 20%), fertilizer nitrogen applications can be reduced.
High level of pasture production: Apply 40–60 pounds of nitrogen per acre three times a year (March 15–April 15, June 1–15 and August 1–15). This approach will optimize the pasture’s use of irrigation water and promote vigorous growth throughout the growing season.
Moderate level of pasture production: Allow stored soil resources to provide nitrogen for spring growth. Apply 40 to 60 pounds of nitrogen per acre twice per year (June 1–15 and August 1–15).
Low level of pasture production: Apply 40–60 pounds of nitrogen per acre in a single application (early spring, late spring or early summer after the spring flush of forage production). This approach, if applied every year, may limit forage quantity and quality over time.
Nitrogen fertilization practices for nonirrigated pastures
From 12 to 18 inches of precipitation: Apply 20–30 pounds of nitrogen per acre in early spring to increase pasture production during the late spring and early summer. Further nitrogen fertilization is not recommended.
Less than 12 inches of precipitation: No nitrogen fertilizer is recommended.
Clovers and other legumes are sometimes added to grass pastures. As noted above, a small amount of legume seed can offset some nitrogen fertilizer requirements. Consult your OSU Extension Service office personnel or your fertilizer dealer about fertilizer rates under these conditions, as nitrogen fertilization needs may be decreased or eliminated. These sources can also provide local information about the proper fertilizer, or blend of fertilizers, that will supply needed nutrients economically.
Forage-specific dangers to horses
Some varieties of tall fescue and ryegrass, intended for use as turf, are purposely enhanced with a fungus (endophyte) that grows within the plant. It benefits the plant with increased heat tolerance, drought resistance and insect and disease resistance, but it also produces a toxin that causes reproductive and other health problems in livestock. Pregnant and lactating horses are particularly vulnerable. When buying tall fescue or ryegrass seed, select an endophyte-free forage variety.
Use irrigation water efficiently
Many pastures in Eastern and Central Oregon are dryland. The plants depend on 8–20 inches per year of rain and snowfall to supply their water needs. These pastures are productive during the spring and early summer and sometimes for a brief time in the fall. Unless additional water is supplied through irrigation, the plants are dormant during the summer when hot, dry weather, combined with long days, reduces moisture stored in the soil. Plants also become dormant again under cold winter conditions.
Figure 3 shows the typical season’s water demand by forage plants. Notice that the demand increases sharply from February through July and then drops off as the days become shorter and cooler.
Irrigation, combined with the correct type of pasture plants, nutrients and grazing management, will maintain active summer growth and provide supplemental feed during dry months. Your ability to irrigate depends on whether your property has irrigation rights.
Several irrigation methods are available, including flood, hand- and wheel-line sprinklers, pod-line (such as K-Line), irrigation “guns” and pivot irrigation systems. The method you choose will depend on the system that came with the farm; the size of the farm; and the amount of labor, time and money available. Take care to protect the pipe from curious horses.
Do not leave horses in the pasture while irrigating. To avoid plant and root damage and soil compaction, wait two to four days until the irrigation water has soaked into the soil before turning horses back onto pastures.
Irrigation management is based on matching the plants’ water needs with the amount of water applied. For optimal production, pasture plants require 26–30 inches of water a year. All soils store water. Fine-textured soils, such as clay, can store more water and for longer periods of time than coarser soils such as sandy loams. Sandy soils store little water. Plants absorb water efficiently from the soil until about half of the stored water is used. Irrigation or precipitation refills the soil’s storage capacity.
Ideally, irrigation is stopped before water is wasted by running off the field or sinking below the rooting depth of pasture plants. The time between irrigation sets depends on the season, the weather, your soil’s storage capacity and the rate of plant growth. In the hottest season, a growing pasture uses about 0.4 inch of water per day.
Irrigation is a technical skill and requires mastery of many details. An irrigation supplement to this publication is available online at OSU Forage Information System. An irrigation specialist at your local USDA Natural Resources Conservation Service office can assist in the development of a water management plan. Oregon State University Extension offices also can assist with irrigation questions, resources and management techniques. See “For more information” for sources on irrigation scheduling methods.
Step 3. Use buffer strips to protect water quality
Vegetated buffer strips protect creeks, other surface water and your wellhead from runoff from paddock areas or manure piles. Buffers can be wide, grassy strips (including your unused pasture) or strips of trees, shrubs or both. They stabilize stream or canal banks, filter some pollutants from runoff and may provide shade. Buffers alone can’t prevent contamination of well water or streams, however; the key is to reduce contamination at its source.
Summer pasture/winter buffer
One of the most common buffers consists of irrigated pasture used for grazing or hay in the spring and summer, but left ungrazed as a buffer during times of slow plant growth or potential flooding. This buffer is not a narrow strip along a waterway, but a series of wide, intensively managed pastures. These pastures are grazed and rested throughout a carefully managed rotation to maintain a grass height of at least 3–4 inches year-round. Small buffer strips between paddocks can also provide a buffer between horses, saving on fence repair and vet bills, while filtering runoff from the paddocks.
Stream/canal buffers
Vegetated buffers are valuable along streams and canals to stabilize the bank and provide a natural area for wildlife. These areas can be planted with a variety of trees, shrubs, grasses and other plants. Exclude horses from these areas or closely monitor light springtime grazing because horses may browse or trample trees and shrubs. If buffers are grazed, minimize horse access to the waterway with permanent fencing or portable electric fencing. This will prevent bank trampling and keep manure and eroded soil out of the water.
How wide should the buffer be?
Buffer width depends on the slope of the field, soil type and plant density. Wider buffers provide greater protection. Increase buffer width under these conditions:
- On steeper sites.
- On clay, dense or compacted soils.
- Where plants are widely spaced.
- If the area above the buffer is not well vegetated.
- If there is a large concentration of animals and manure that can run off.
Width usually is not an issue with summer pasture/winter filter. Almost all pastures are wider than 35 feet. If you don’t have room for a buffer between a paddock and drainageway, consider a soil berm (a raised strip of ground) to catch the runoff and direct it to a filter strip or catch basin.
How do I prepare my grass buffer each fall?
- Always leave grass at least 3–4 inches tall.
- Do not apply fertilizer or stockpiled manure to the buffer in the fall. The buffer’s role is to capture nutrients and bacteria.
- Remove horses about 30 days before consistent winter conditions or seasonal flooding are expected. Dragging pastures before a hard freeze breaks up manure and prepares it for rains or irrigation. This will allow manure deposited in the field during grazing to break down and provide an opportunity for plant regrowth. Dragging will expose parasite larvae to harsher winter conditions.
- The buffer period should extend into the spring until soil is no longer saturated, grasses are tall enough to graze or cut and the chance of streamside flooding has passed.
Step 4. Manage manure and bedding
Cover and compost manure
A 1,200-pound horse produces 1 cubic foot of fresh manure every day. This stall waste can be a soil-building resource or a source of muck, weeds, parasites, flies and water pollutants. Improve your manure handling and composting techniques with these six tips:
- Site manure storage and compost piles to protect surface and ground water.
- Isolate waste piles from streams and irrigation ditches.
- Reduce stall waste volume.
- Cover waste piles to control moisture levels, reduce runoff and control flies.
- Compost manure for at least a year to kill weed seeds.
- Spread manure and compost when plants can use it.
Site manure and compost piles to protect surface and ground water
Consider the soil types on your property when locating long-term, stall-waste storage. Sandy soil drains rapidly, allowing nutrients to travel quickly to groundwater. Water moves more slowly through clay soils, but these soils might permit surface runoff. The other soil types fall between sand and clay in their drainage abilities.
Observe the pathways that running water takes across your property. Do not locate manure storage in low spots, drainageways or near irrigation ditches. Store all waste above the floodplain so it won’t be carried away by high water.
Keep manure away from roof and downspout runoff. Well-planned trenching diverts water away from waste piles (see “Other ways to reduce runoff and mud”). Storing stall waste on less desirable sites requires more care and monitoring. Site the manure pile at least 50 feet downslope from your wellhead.
Isolate waste piles from streams and irrigation ditches
Maintain vegetated buffer strips between waste piles and bodies of water to trap flowing contaminants and take up water-carried nutrients (see “Vegetated buffers”).
Reduce stall waste volume
There’s nothing you can do about the volume of waste a horse produces, but you can affect the size of your manure pile by reducing the amount of bedding used. The amount required to absorb urine is far less than many horse owners provide.
Stall mats provide a cushioned, level surface for standing. They reduce dust and prevent digging. Despite the initial investment, stall mats do reduce bedding costs.
Wood shavings and straw are effective in reduced bedding systems. Wood pellets look like wood stove pellets specifically manufactured for animal bedding are easy to pick, low in dust, more absorbent than shavings and effectively control ammonia odors. They take up less room in a compost pile than shavings. Do not use wood stove pellets as livestock bedding.
Regardless of the bedding used, composting reduces waste volume.
Cover waste piles to control moisture levels, reduce runoff and control flies
Effective manure management requires adequate storage. Size storage areas according to the volume of manure produced.
The most important practice for proper manure management is also the least expensive: cover stall waste piles with a weighted tarp. Water-filled milk jugs tied to the tarp make excellent weights. When evaporation exceeds rainfall, tarping helps maintain adequate moisture. Manure and bedding are difficult to rewet once they dry completely. When rainfall exceeds evaporation, tarping prevents saturated manure piles and undesirable runoff. Tarping also reduces fly habitat.
The next level of manure management is to provide a concrete pad and, perhaps, use curbs and weighted rain tarps. Top-of-the-line manure management involves a concrete pad with a roof, gutters and downspouts. Many publications show examples of roofed and open storage structures and can help you estimate volumes for adequate storage. Classic three-bin systems can be adapted to many situations.
Compost manure
Composting manure creates a valuable resource from a potential pollutant. Composting creates "slow-release" nitrogen and provides organic matter to your pasture. Composting requires an aerated pile that receives enough moisture for microbes to break down the manure and generate heat to kill off pathogens. The specifics of composting techniques vary, so every horse owner can implement a process that best suits their site, number of animals and available equipment. See Agricultural composting and water quality for more composting ideas.
Inadequate moisture is the No. 1 reason manure piles fail to compost. Check moisture levels when you turn the pile; add more water if needed. You should be able to squeeze one or two drops of moisture out between your fingers, but many drops falling freely indicate too much moisture. Too much water promotes odor-causing anaerobic conditions. Drip emitters are an effective way to add water to compost piles.
Sufficient aeration speeds composting and promotes heating, which in turn destroys many parasites, fly larvae and weed seeds. When using sawdust bedding, improve aeration by adding 10% by volume of large wood chips. Another method is to lay lengths of 4-inch perforated pipe across the pile every 2–3 feet of pile depth, leaving pipe ends exposed. Pipes are often damaged, however, if piles are turned by heavy equipment.
Tractors and front loaders gain traction when compost is stored on a concrete pad. Turning with heavy equipment is easier if the equipment can push the compost against a reinforced wall. Turn small compost piles by hand.
Spread manure and compost when plants can use it
Spread no more than ½ inch of compost at a time, two times a year, when conditions permit field access and plants are actively growing. Spreading compost in spring is ideal for plant growth. In late summer, short pastures allow efficient compost application just before cooler fall temperatures stimulate grass growth. Empty manure storage provides space for the winter’s manure and bedding accumulation.
Don’t spread manure in late fall when dormant plants are unable to take up nutrients. This practice often leads to surface and groundwater contamination.
Step 5. Manage weeds to protect your horses
Strategies for weed control
Major weed problems are rare in well-managed pastures. Grazing management is the most effective tool in weed control programs. Manage beneficial species so that weeds have a difficult time gaining a foothold. Here are six steps to successful weed control:
- Identify the weed.
- Pull, mow or dig established weeds.
- Bring in other livestock to graze undesirable plants.
- Cut and remove weeds before seed heads develop.
- If you choose to use herbicide, select the right one and apply it at the right time in the weed’s growth cycle at the right rate. Read the label and follow all directions.
- Use the grazing practices outlined in this publication to encourage desirable pasture plants.
Because horses do not graze all pasture plants to an even height, some mowing may be needed. Mowing a pasture to 3–4 inches after moving horses to a new pasture helps control weeds and prevents grasses from developing seedheads and becoming dormant.
Identify weeds by using various resources (see “For more information”) or by taking a sample plant to your local office of the Oregon State University Extension Service. Weeds differ in their life cycles (annual, biennial, perennial), and each type requires different management strategies. They also differ in the threat they pose to a grazing system. Some are toxic, some are noxious, meaning they spread quickly and dominate the pasture, and some are harmless. These factors influence whether and how weeds should be controlled.
Remove established weeds by mowing, pulling or digging. Sheep and goats eat more broadleaf plants than do horses and can keep weeds under control.
If you choose to use an herbicide, it is critical to time the application to the correct growth phase of the plant. The product label provides information about allowable uses, restrictions and application timing. It is a violation of federal law to apply a pesticide in a manner inconsistent with its labeling. Read the label and follow the instructions. Follow all safety precautions and grazing restrictions.
The best way to protect horses from toxic weeds is to develop and implement a comprehensive weed control program. See the OSU Forage Information System’s weed control methods and resources for weed control in “For more information.”
Step 6. Install rain gutters and downspouts
Central and Eastern Oregon experience annual precipitation ranging from 8 to 20 inches. Although this amount of precipitation may seem insignificant, water from melting snow and heavy rainfall events can saturate pastures and corrals and cause soil erosion. In addition, the roofs of barns and other farm buildings collect large amounts of precipitation and deposit water that can create mud and erode soil. See OSU Climate and weather resources to find precipitation for your location.
Installing gutters and downspouts on your farm buildings directs water away from high-use areas around the barn and immediately reduces the quantity of mud.
Planning for downspouts and gutters
To keep clean water clean, downspouts must direct water away from animal confinement areas. In some instances, you might need to use plastic pipe to carry the water beyond the animal confinement area to a vegetated area. Downspout systems can be designed to divert water to stock watering tanks for livestock use or into drainage ditches.
To protect downspouts from damage, install a physical barrier, such as heavy PVC pipe or a hot wire, or make the downspout inaccessible to horses. In high-traffic areas, bury pipes for protection from horse and vehicle damage.
Some options for gutters
Economical: Installing gutters and downspouts is an easy do-it-yourself project. Home improvement retailers carry a variety of suitable materials. Snow guards reduce the potential for snow and ice damage to gutters.
Top-of-the-line: Numerous businesses specialize in installing aluminum continuous (seamless) gutters. Some businesses also have specialized gutter systems designed for areas that receive large amounts of snow.
Other ways to reduce runoff and mud
The natural drainage of your land may direct water into high-traffic areas around your barnyard. If this is the case, consider additional ways to divert water, such as French drain lines, drainage tiles, grassed waterways, water bars (like an inverted speed bump for water runoff), ditches and dry wells. Design help is available from your local Soil and Water Conservation District, USDA Natural Resources Conservation Service or Oregon State University Extension Service office.
Step 7. Protect your household water supply
Know your well
To assess the effect livestock have on the quality of your drinking water, first locate your well in relation to your livestock and manure storage areas. Also, locate your septic drain field, petroleum storage tanks, chemical storage and other potential sources of contamination relative to your well.
Learn all you can about your well. Perform a visual inspection for cracks in the casing or other deficiencies and read your well log. The county water master can help you find this document. These questions may point to items of concern — or relieve your mind:
- Is the well located in a low area of your property?
- Is the wellhead properly sealed, and are the standpipe and screen in place?
- What is the age, depth and construction quality of your well?
- What is the depth to groundwater?
Practices to protect your drinking water
- Fence horses and other livestock away from your wellhead. Keep livestock and manure piles at least 50 feet from the wellhead.
- Use channels and berms to divert stormwater and drainage away from your wellhead.
- Keep clean water clean and minimize manure-contaminated water by using gutters, downspouts and pipe to route clean water away from manure and heavy-use areas (see “Step 6. Install rain gutters and downspouts”).
- Test well water annually for Escherichia coli (E. coli) bacteria and nitrate — these indicate a connection with manure, fertilizers, septic-system waste or similar materials. E. coli bacteria should never be present in well water.
- Do not leave a hose immersed in a stock tank. Install an anti-siphon valve for all outdoor hose bibbs, especially those used to water livestock and mix chemicals.
- Inspect your well’s sanitary seal. If you have doubts about its integrity, hire a well driller to inspect it.
For more information
Agencies and organizations
The following sources can provide technical assistance and information about grant programs. Call these statewide numbers or visit their websites to find the local staff person in your area.
Oregon State University Extension Service
Oregon State University Extension Service offers educational programs, seminars, classes, tours and publications to guide landowners in managing their resources.
Oregon Department of Agriculture, Natural Resources Division
ODA’s Natural Resources Division oversees the Agricultural Water Quality Management Program, issues permits, helps livestock owners comply with water quality requirements and provides support to Soil and Water Conservation Districts.
USDA Natural Resources Conservation Service
The Natural Resources Conservation Service is a federal agency that implements federal cost-share programs to improve management of natural resources on private lands. It works closely with Soil and Water Conservation Districts. It also provides information on soil types and soil mapping.
Soil and Water Conservation Districts
Soil and Water Conservation Districts are subunits of government with locally elected boards. They help landowners improve management of natural resources through technical and financial assistance.
Watershed councils
Watershed councils are local groups that bring diverse interests together to resolve local natural resource issues. They conduct watershed assessments, develop and fund watershed enhancement projects, provide educational opportunities and work with local stakeholders to improve watershed stewardship.
Resources
Horse facility management
Hill, C. 2005. Horsekeeping on a Small Acreage: Designing and Managing Your Equine Facilities, 2nd edition. Pownal, VT: Storey Publishing.
Wheeler, E. 2005. Horse Facilities Handbook. Ames, Iowa: Midwest Plan Service, Iowa State University.
Pasture and grazing management
Bittman, S., O. Schmidt, and T.N. Cramer. 1998. Advanced forage management: A production guide for coastal British Columbia and the Pacific Northwest. Agassiz, British Columbia: Pacific Field Corn Association.
Barnhill, J., S. Olsen, R. Sessions, D. Minder, T. Julen-Day, N. Hansen and C. Garn. 2000. Small pasture management guide for Utah. Utah State University Extension.
Cobourn, J. et al. 1995. Small ranch manual: A guide to management for green pastures and clean water. EB-95-02, Reno, NV: University of Nevada Cooperative Extension.
Gerrish, J. 2004. Management-intensive Grazing. The Grassroots of Grass Farming. Ridgeland, MS: Green Park Press.
Grass Growth and Regrowth for Improved Management
Hall, M. and P. Comerford. 2005. Pasture and hay for horses. University Park, PA: PennState Extension.
Horse Forage and Forage Management (Noble Foundation Horse Pastures).
Management of small pastures. Publication #2906, University of California Agriculture and Natural Resources.
MatchForage, Oregon State University.
Murphy, B. 1998. Greener Pastures on Your Side of the Fence: Better Farming with Voisin Grazing Management. Colchester, VT: Arriba Publishers.
National Forage & Grasslands Curriculum
Orloff, S., B. Hanson, and D. Putnam. 2003. Utilizing soil-moisture monitoring to improve alfalfa and pasture irrigation management. Davis, CA: Plant Management Network.
Pasture management for horses on small acreage. Fort Collins, Colorado: Colorado State University Extension.
Rotational Grazing: Livestock Systems Guide. ATTRA—Appropriate Technology Transfer for Rural Areas
Forage species for the West
Forage Information System. Oregon State University Department of Crop and Soil Science.
Soil and fertility analysis
Brewer, L., N. Andrews, D.M. Sullivan and W. Gehr. Agricultural composting and water quality, EM 9053.
Cappellazzi, S., C. Sullivan, G. Jones and L. Brewer. 2024. Get actionable results from a soil, plant or environmental testing lab. EM 8677, Corvallis, OR: Oregon State University Extension Service.
F. Melissa, J. Choate and E. Murphy. 2022. A guide to collecting soil samples for farms and gardens. EC 628, Corvallis, OR: Oregon State University Extension Service.
Horse nutrition
Coleman, B. 1988. Basic horse nutrition. ASC-114, Lexington, KY: University of Kentucky Cooperative Extension Service.
Feeding Horses: A Practical Approach 21134 (Suburban Rancher). University of California Agriculture and Natural Resources.
Plants, weeds and toxic plants
Burger, S. 1996. Horse Owner’s Field Guide to Toxic Plants. Breakthrough Publications.
Cornell University Poisonous Plants Informational Database
USDA ARS Poisonous Plant Research Laboratory
Weathers, S. 1998. Field Guide to Plants Poisonous to Livestock: Western U.S. Fruitland, UT: Rosebud Press.
Whitson, T. et al. 2012. Weeds of the West, 11th ed. Jackson, WY: Western Society of Weed Science.
Acknowledgments
The authors thank faculty at Colorado State University, University of Idaho, Montana State University and Utah State University for their review and technical advice. The authors also thank horse farm owners Holly Endersby of Pollock, Idaho; Sally Kuhl of Bend, Oregon; and Liz Lotochinski and Andy Zook of Bend, Oregon, for their review and guidance.
About the authors
