Pasture: Evaluation and Management of Existing Pasture

Bob Hendershot, Retired State Grassland Conservationist

As we begin to move into spring, we need to start thinking about spring forage growth and how we will be managing our pastures over the course of the new year.

Pasture management is very important for grazing animals; cattle, horse, llama, and sheep owners. By managing pastures more effectively, land managers can increase forage production, lower production costs, improve aesthetics, and promote a healthier environment. The benefits of a well-managed pasture include reducing environmental impacts of your operation, including movement of soil and manure to water bodies; improving property aesthetics, which makes for good neighbor relations, and increases property value; and providing feed and recreation for your horses. Using a rotational grazing system can enhance these benefits.

For optimal health, horses and llamas need to eat 1 to 1.5% and cattle and sheep 3 to 4 % of their body weight in hay or pasture daily (15 lbs. of dry matter intake for a 1,000 lbs. horse; 30 to 40 lbs. of dry matter intake for a 1,000 pound beef animal).

Evaluation of Current Pasture:
Begin by evaluating your pasture. Move hay feeders and water troughs to encourage even plant growth and reseed with grass species that can stand up to  hoof  action (such as orchardgrass, Kentucky bluegrass, meadow fescue, festulolium, fungus free or novel endophyte tall fescue, and perennial ryegrass). When planting, check to see if bare areas are heavily compacted. If you can’t push the blade of a trowel into the ground, loosen the soil with a tiller before reseeding. Next, eliminate areas of standing water by regrading the area or installing drains after checking with your local government environmental agency to be sure that it is not a wetland. Eliminating standing water will benefit your pasture; it will also be an aid in disease control, since mosquitoes and other insects tend to breed in standing water.

Identify plants in your pasture and see if what you seeded last spring is present. You would like to see plant diversity with a minimum of 3 to 4 grasses and 2 legumes each making up more than 10% of the forage stand. You also want to remove poisonous plants with an herbicide or cultural means. If the pasture is less than 50% desirable plants it is time to strongly consider a complete renovation, 51% to75% over seed and more than 76%  frost seed. Walk your pastures and take photos, good notes and evaluation forms in May, July, and October.

Resting pastures is critical! Recovery time for grasses ranges from 10 to as many as 60 days, depending upon season, weather, and soil characteristics. Generally expect to wait at least 14 days for grasses to regrow to grazing height in spring, and 30 or more days in summer. A good rule of thumb is to avoid exceeding 7 days on any one paddock. Divide your total pasture area into a minimum of 5 paddocks, and rotate animals to a new paddock at least once a week. This system will allow each paddock to rest for 28 days. If it is not possible to do all the divisions at one time do it in stages over a several year period. Two paddocks are better than one and three better than two.

A rule of thumb is to graze animals when grass is 6 to 8 inches high. Rest the pasture when it is grazed down halfway (3 to 4 inches high). Maintaining (3 to 4 inches) will keep 1200 to 1600 lbs./acre of dry matter leaf area that will capture 100% of the available sun light for maximum plant growth. “Graze ½, leave ½.” Grazing 50% only removes 2-4% of growth but grazing it 60% removes over 50% of growth! Grazing plants too short removes the growing points of grass and it will take longer for the pasture to recover, allowing more weeds to invade, and increase the chance for consumption of toxic plants. However, a Kentucky bluegrass, ryegrass and white clover pasture can be grazed beginning at 4 inches of height. Bluegrass and ryegrass are tolerant of shorter grazing heights, and the sunshine will stimulate white clover growth. The worse disaster is over grazing the farm.

In springtime when grasses are growing quickly, you may need to move the animals through the rotation faster or work in a mowing regime as well in order to prevent plants from getting too mature and unpalatable before they’ve been grazed. If you make hay, you may choose instead to withhold 1/2 of your pasture from your grazing system so that you can harvest a first cutting from it. After regrowth, this area may be added back into your rotation system.

Experiment with portable electric fencing systems to subdivide pastures into paddocks. Paddocks are grazing areas subdivided from the pasture field. Ensure that the permanent perimeter fencing is sturdy and reliable. Portable or temporary fencing allows flexibility in how much area you give your horses daily. It also facilitates mowing and haying operations due to the ease of picking it up and getting it out of the way. Over time you may find that you are placing your fences in the same places, and you may choose to erect permanent fencing in its place.

Keep grasses in their “vegetative” state with a combination of grazing and mowing. Harvesting grass before it gets too tall will prevent it from becoming reproductive, also known as “going to seed.” Mature grass is coarser, stemmy, and not as palatable or nutritious as leafy, actively growing plants. Clip weeds before they form a seed head to reduce the weed seed in your pastures and control woody plants such as tree and shrub seedlings, which may invade open areas. Ideally, a paddock should be mowed as soon as possible every time animals are removed and rotated on to the next paddock. Just like grazing, you should allow grasses to grow to 6 to 8 inches and mow to 3 to 4 inches if not actively grazing to keep pasture grass healthy.

Soil test pastures to determine the need for fertilizer and lime, and follow recommendations. If pasture is new or has not received lime and fertilizer for many years, you may wish to test for 2-3 years in a row to establish a healthy fertility level. After that, a test every 3 years is sufficient. Remember that if soil pH is too low, any fertilizer you apply may not be accessible to the grass, resulting in a waste of money! Fertilizer is the least expensive way to improve profitability of a pasture. Twenty pounds of additional forage dry matter can be grown with the addition of one pound of nitrogen. Fertilizing a pasture is much different than fertilizing a crop or even a hay field. Grazing animals leave 75% to 95% of the phosphorus and potassium in the pasture where the animals place it is the management issue.

“Drag” or chain harrow pastures as needed to break up and spread manure piles. This will help manure to be broken down more quickly, spread fertility more uniformly, and dry out parasite eggs more quickly. During wet weather, parasites may not be controlled by this method, so manure should only be spread during dry weather periods.

Animals should be fenced out of wetland areas because they can cause damage to these fragile environments. When thinking about fencing, you should consider safety first. Fences should be clearly visible and not located at the base of a hill where animals can easily run into them.

– Flack, S. Undated. Pasture Management for Horses. Cambridge, VT.
– Herd, R.P. 1986. Pasture Hygiene: A Nonchemical Approach to Equine Endoparasite Control. Modern Veterinary Practice 67(1): 36-38.
– Hill, C. 1990. Horsekeeping on A Small Acreage: Facilities Design and Management. p. 106.
– Peterson, P.R. 1997. Developing a Grazing Management Plan for Horses. Crop and Soil Environmental News.
– Russell, M.A., White, H.E., and Antoniewicz, R.J. 1993. Pastures for Horses. Horse Industry Handbook. 730-1-730-9.
– Singer, J.W., Bobsin, N., Bamka, W.J., Kluchinshi, D. 1999. Horse Pasture Management. Journal of Equine Veterinary Science 19(9): 540-545,585-586,588-592.
– Washko, W. 1968. An Outline for Pasture Improvement. University of Connecticut.