These pastures include wheat and rye, with considerations for barley, annual ryegrass, oats, and triticale. Along with bermudagrass, the winter pastures rank high for horse forage.
The grasses can be planted on tilled land, sod-seeded into bermudagrass, or double-cropped with crabgrass and other summer annual grasses. Combinations of bermudagrass or crabgrass and well-managed winter pasture are an excellent nearly yearlong approach to horse pasture in Oklahoma.
Well-managed winter pastures can provide forage from November to late May or early June, depending on the forage combinations. Rye will usually provide earlier grazing, regrow better during cold, and produce excellent forage yield. Winter pastures can be greatly refined and fitted to individual needs.
These forages have to be established annually, which creates the disadvantage of being more troublesome and costly. However, because they have a high nutritional value, the cost can be easily offset when compared with the cost of purchased feeds. Additional information on cool-season forages and horse performance can be found in the section on horse research on forage.
Varieties. Cattle grazing studies show that oats are more palatable than wheat, wheat is more palatable than rye, and rye is more palatable than barley. Cattle consume all classes of small grains, and the same is true of horses. It is wise to plant these in pure stands for horses, since they tend to be more selective grazers. Intake of these lush forages will not likely decline if horses have access to only one type at a time.
Most varieties of small grains are bred and selected for grain production, with forage being a by-product. There are several good forage varieties of cereal rye: 'Bates', 'Bonel', 'Elbon', 'Oklon', and 'Maton'. These varieties can be expected to outproduce other small grains for fall and winter forage. They have the ability to grow at a lower temperature, which makes them dependable in a grazing program. Of these forages, rye terminates spring production the earliest.
Most oat varieties lack winter hardiness to always survive Oklahoma's winter temperatures when planted early for fall-winter pasture. Oats are not generally recommended for fall planting, but they are dependable as spring planted pasture. Variety choices are limited.
Soft wheat grown in southern and southeastern Oklahoma and into Texas and Arkansas is usually more productive than hard red winter wheat when planted early for fall pasture. Most varieties of hard red winter wheat will produce stockpiled fall forage when planted early, but practically no winter forage regrowth occurs after mid-November. They produce abundant spring forage. Proven hard red winter wheats are trustworthy and can be planted throughout Oklahoma and Texas and adjoining regions. There are many acceptable varieties common in the seed trade.
Annual ryegrasses are an excellent choice for the southeastern two-thirds of Oklahoma, Arkansas, and Texas. They can be easily established as pure stands in clean tilled fields or in grazedoff bermudagrass or crabgrass. They provide excellent forage from March to June. There are several excellent varieties. 'Marshall' is a proven winter-hardy type with high production. Other good varieties are 'Ribeye' and 'Jackson'.
Rescuegrass-type bromegrasses are available as 'Stocker' and 'Matua'. These grasses are excellent horse pasture and hay. They can be managed for perpetual volunteer stands, as ryegrass and crabgrass are. Stocker bromegrass can be green into summer up to a month after annual ryegrass matures.
Clovers and vetch can be a part of the spring to midsummer forage. They are discussed elsewhere.
A good combination is a mixture of cereal rye or a variety of winter wheat and annual ryegrass or a winter legume. Under rotational grazing, this mixture will give a better distribution than a single kind of forage through fall, winter, and spring. A mixture can be devised for any part of the south central United States.
Establishment Techniques. The key to a successful clean-seedbed winter pasture is getting it established as early in the fall as feasible and developing the plants as fast as practical while fall weather is favorable for growth and fall stockpiling of forage. Moisture and plant nutrition are the limiting factors in getting good stands and rapid plant development.
The soil is a water reservoir for plant growth, so the management of the soil in relation to available soil water becomes very important. In the drier areas of Oklahoma, it is necessary to plant small grain for winter pasture as a single-season crop in either a tilled or chemical-fallow soil management regimen in order to have sufficient soil moisture for plant growth. Clean-till management of the soil would include a combination of tillage tools to control summer weeds, break up surface and subsoil compaction, and smooth and create a soil medium for excellent seed placement and early plant growth.
Chemical fallow involves relying on a combination of herbicides to conserve moisture by controlling vegetation. This method also depends on sufficient plant residue from the previous year to provide a protective soil cover. The cover intercepts rain droplets to stop erosion and conserves the moisture by reducing soil evaporation. Chemical fallow can be used on soils having more than a 3 percent slope if crop residue is maintained to control erosion.
The clean-till method of seedbed preparation has the disadvantage of depending on machinery. To prevent soil erosion, clean till should be done only on land that has less than a 3 percent slope. When using tilled pasture, remove (rotate) horses to be sure to allow pasture establishment and control excessive destruction of the stand and forage production caused by somewhat continual trailing, running, and overgrazing.
Overseeding winter forages into bermudagrass or crabgrass residue is a common practice for the eastern two-thirds of Oklahoma, among other places. Overseeded winter pasture coupled with proper fertilizer can produce economical winter and spring pasture. Research at the Noble Research Institute has shown that overseeded rye can be produced for about fifty dollars per ton of forage. Many horse farms overseed pastures into bermudagrass because more extensive land area is unavailable for tilled pastures.
Overseeding any cool-season annual grass into bermudagrass is often done with special planting equipment that will place the seed in contact with the soil or into a furrow up to 1 inch deep. Broadcast planting or planting with a common drill can also be done successfully. Most no-till drills satisfactorily plant into a grass sod. The row opener of these drills should be placed behind a colter that cuts a slot through the grass sod. The disk row opener or narrow furrow opener will allow seed to be placed into the furrow. Press-wheel attachments following the row opener will press the soil against or over the seed to give it firm contact with the soil. Drills should have a fertilizer attachment so that a nitrogen-phosphorus starter fertilizer can be placed with the seed.
Row spacing is a consideration on some makes of drills. A 6- to 7-inch row spacing is better than an 8- to 10-inch or wider spacing. All narrow spacings are considerably better than row spacings wider than 10 inches.
Common grain drills and fertilizer spreaders can be used to effect a no-till drill planting, which is especially applicable when more precise no-till drills are unavailable. The common drill technique usually results in better stands than broadcast seeding does. Two bulletins available from the Noble Research Institute provide detail about the common drill and broadcast procedures: Low-Input Overseeding, publication number NF-FO-99-17 (Dalrymple, 1999b), and Using Common Drills, Fertilizer Spreaders, and Carriers to Plant Difficult Seeds, publication number NF-FO-99-15 (Dalrymple, 1999c).
Broadcast planting can be successful where drills are unavailable. Good stands of winter pasture can be achieved by broadcasting seed into bermudagrass or other grass residues. Some kinds of winter pasture perform better in this case than others. Among the best tend to be cereal rye, barley, annual ryegrass, rescuegrass, hairy vetch, and crimson clover. Second-order success tends to come from wheat, oats, and triticale. Although the efficiency of getting a stand from broadcast plantings is lower than that with a drilled stand, broadcast stands can be successful. Noble Research Institute personnel have broadcast-planted rye, annual ryegrass, and other forages in over 250 paddocks of bermudagrass residue over ten years with a high rate of stand success. Good fertilization and rotational grazing allows good pasture production from these broadcast-planted stands. Clovers or ryegrass can be broadcast-planted on the soil surface of clean tilled lands before or after drilling. On a clean-till seedbed, it is best that clover or ryegrass seed be slightly covered with 1/4 to 1/2 inch of soil, which protects the inoculant that is attached to the clover from direct sunlight. One ideal planting method is to mount an electric-motor-driven broadcast spreader on the front of the tractor so that seed are dropped in front of the drill. The drill disk, or row opener, can slightly cover some seed.
Planting Dates and Rates. Small grains and annual ryegrass for pasture should be planted earlier and at higher seeding rates than is conventional for grain production. The following table gives guidelines on planting dates and rates for small grains, annual ryegrass, rescuegrass, some clovers and other legumes, and mixtures. The early fall planting date target is ideal, but plantings can continue to March 1 in southern Oklahoma. In very late plantings, certain kinds and varieties should be used. Planting rates and dates are not given for all forages because that information is available from the usual agricultural information sources.
Oats, barley, annual ryegrass, and rescuegrass can all be successfully spring planted. Seeding rates are the same or up to 50 percent greater than that of fall planting if a thick stand is wanted. Spring planting dates in southern Oklahoma are about February 1 to March 10.
Fertilization. To produce optimum forage, winter forages require added plant nutrients. Small grain yields may range from 1 to 3 tons or more per acre. One ton of forage will contain 60 pounds of nitrogen (N), 12 to 15 pounds of phosphorus (P), and 60 pounds of potassium (K). These nutrients cannot all be supplied by the soil.
The nutrient base in the soil can be determined from a soil test. Supplemental fertilization can be determined according to the soil test analysis and other factors such as soil moisture and type, yield goals, and plant variety.
A typical fertilization program would consist in applying a starter fertilizer containing phosphorus and nitrogen by banding it with the seed at planting. Then a nitrogen fertilizer would be applied during both fall and spring. The first application should be made soon after plants emerge; the second, in mid-February.
For a winter pasture mix of small grain and clover or vetch, delay the first top-dressing of nitrogen two to three weeks so that the clover can become fully established. Nitrogen fertilizers can be toxic to the rhizobium attached to the clover seed, and excessive nitrogen will cause too much small grain production, which increases competition, and that can kill the small legume plants.
Total nitrogen top-dressing rates vary from 50 pounds of actual nitrogen per acre for low production goals to 250 pounds of actual nitrogen per acre for upper-level production goals.
Overseeded winter pasture in bermudagrass or crabgrass residue should be fertilized much the same way. However, it is important to make the first nitrogen top-dressing soon after hard freezes to reduce the summer grass uptake of the nitrogen and encourage early production of the winter pasture component. It is also important to use a minimum of 100 pounds of actual nitrogen per acre.
Soil acidity can be a limiting factor in forage production. A soil pH below 5.5 will limit growth on some varieties of small grains, and a pH below 6.0 will limit growth of clover plants. Soil acidity can be corrected with an application of lime, the amount to use determined by a soil analysis.
Pasture and Grazing Management. After the stand of small grain emerges and is growing, the need for management is just beginning. If the profit potential is to be realized, the plants must make good production and then be properly used.
Small grains planted early are susceptible to insect infestation. From the fall until cold weather hits, observe plants every one to three days for possible infestations of armyworms, cutworms, and other damaging insects. Look for leaf damage or discoloration. Watch for areas within the field that have a different color and growth pattern from adjacent areas. Control insects with insecticides as necessary.
Use plant height and density as a guideline to determine the beginning grazing date. A plant must have time to develop an adequate root system before forage is removed, because a shallow, weak root-crown system will cause the regrowth process to be slow and limited. Plants grazed too soon will regrow very slowly and produce much less. When plant leaves are removed, energy to grow new leaves must come from the root-crown lower-stem system. A minimum of 8 inches of growth is the normal guide for the beginning grazing date for rye in southern Oklahoma. Less growth may be acceptable for wheat. Plants should not be grazed to a residue height shorter than 3 inches. Leaf area is needed for the plants to continue growth to make a rapid recovery after being grazed. There will be a few fall seasons that are too dry to produce adequate growth for fall grazing, and grazing should not be done until spring when growth is better. If there is a limited amount of properly grazeable pasture by somewhere between November 15 and December 1, it can be grazed to about a 3-inch residue.
Information on the performance of horses grazing winter pasture is somewhat limited. There are research results that indicate that winter forages can provide 100 percent of the diet for the horse that is being maintained, used only lightly, or grown at a moderate level. If you want a maximum daily gain for horses that are growing or have a medium to heavy work load, you will need to provide supplemental feed high in energy.
Stocking rate depends on the availability of forage, the size of the animals, and the number of days needed for grazing. A horse will consume about 2 percent of its body weight in dry matter per day. The average grazing period for rye is from about November 15 to May 1, or 150 days. Rye grown on a sandy loam soil that has low to moderate fertility and is in a 35-inch rainfall area will produce an average of 1.5 to 2.5 tons of dry matter during this period. Assuming that 80 percent would be available for grazing, it would then take about 1 to 1.6 acres to provide forage for one horse weighing 1,000 pounds. However, that number will actually be about 2.0 acres per horse from the fall to March 1 and 1 acre during March and April because of the difference in pasture volume in fall and spring. These projections are for excellent, very productive pasture.
Avoid using winter pasture areas for horse exercise. Small-grain plants are tender and can be damaged severely by trampling effects. A separate area containing water, minerals, hay, and shelter should be provided for the horse to loiter and exercise in.