OWB Management

Old World bluestems are adapted for western Oklahoma and adjacent areas in Texas. They have good establishment characteristics and high forage yield potential when fertilized with nitrogen. Variety selection should be based on soil, climate, and management criteria. April seeding of 2 pounds pure live seed per acre is recommended. Seed shallow (1/8 to 1/4 inch, no deeper) into a firm seedbed.

Apply 30 to 60 pounds of actual N/acre/yr. Soil test for P and follow recommendations. For year round grazing, stocking of about 1.5 acres/yearling steer is suggested. Expected gain is between 0.2-0.5 pounds/steer/day December-March, and 1-2 pounds/steer/day April-September. Under average precipitation conditions, steer gains of 150 to 200 pounds/acre are expected. Old World bluestem has its highest quality and is most productive in June and early July - heavy grazing over this period can realize steer gains of 2 to 2.6 pounds/day and 150 to 300 pounds/acre.

Seven hundred and fifty Old World bluestems from Asia and Europe were tested on the Southern Plains over the past 60 years. Six varieties have proven outstanding in one or more characteristics and are available as named cultivars.

'PLAINS' is a mixture of 30 similar strains blended to give a range in adaptation to possible disease and insect problems, climate, and soil-site conditions. Plains, released in 1972, has been established on thousands of acres. Some strains in Plains are not winter hardy - this problem can be circumvented by purchasing seed produced from local older stands where the more winter-hardy strains have survived.

'WW-SPAR' was selected for outstanding drouth tolerance and forage production. It is a prolific seed producer and is relatively easy to establish. WW-Spar was one of the strains in Plains. It was released in 1983 and has been established on thousands of acres.

'WW-IRON MASTER' is adapted to soils where iron deficiency is a problem on sorghum or other Old World bluestems. Forage production may be less than from WW-Spar, however, the forage with a greater proportion of leaves to stems has the potential to produce good livestock gains. WW-Iron Master is more winter hardy than Plains and WW-Spar, and is about a week later in its growth cycle.

'CAUCASIAN' has outstanding winter hardiness, and under favorable moisture conditions is an outstanding forage producer. Under dry conditions it is less productive than the other Old World bluestems. It has a small basal area and thus is not recommended for upland areas where water erosion is a problem.

'GANADA' is more winter hardy but less productive than Plains, WW-Spar, and WW-Iron Master.

>WW-B.Dahl= is leafy and late heading. This gives it a higher ratio of leaf to stem in mid and late summer, which promotes increased cattle gains during this time. It is a good forage producer on dryland and an outstanding forage producer under irrigation. It is not as winter hardy as >Plains= or >WW-Spar=, therefore, its suggested use is south of a line running from Lubbock to Texarkana, TX.

Old World bluestems are adapted to loamy and clay loam soils. They usually do well on loamy sands, however, establishment can be difficult. Extremely sandy soils, wet areas, or saline soils are not suited to Old World bluestems. Land that has been farmed for many years is usually low in available nitrogen - on such land, N fertilization is needed for Old World bluestems to realize their forage and livestock gain potential. However, N fertilization is not recommended for seedling establishment. Fast growing weedy annuals usually benefit more from N fertilization than slower growing grass seedlings. Phosphorus must be adequate - test soil and follow recommendations.

April seeding takes advantage of late spring rainfall patterns and rising soil temperatures for germination and seedling establishment. A seeding rate of 2 pounds pure live seed per acre is recommended. Seed shallow, 1/8 to 1/4 inch. A firm seedbed is needed to assure seeding this shallow. Sorghum stubble or graze-out wheatland make good seedbeds. Drills for seeding the chaffy seeded Old World bluestem are usually available from Soil Conservation Districts.

Under favorable conditions a few tiny leaf tips should emerge by mid-May. By early June seedlings should be in a two leaf stage anchored by a single root. Moist conditions are now needed for 3 to 5 days for sturdy roots to emerge from the shoot just below the soil surface. By mid to late summer some seedlings may head. Winter grazing of first-year Old World bluestem stands is usually acceptable.

'Ally' and/or 2-4-D used after grass emergence and according to directions are effective for controlling broadleaf weed seedlings. Flash grazing (high livestock density over a few days) can reduce competition from crabgrass and other fast-growing palatable weeds. Mowing when fast-growing weeds are 10 to 12 inches tall and grass is still small is also effective.

PHOSPHORUS (P). Soil tests are good indicators of P availability. Forage production increases of 10 to 70% are probable with P fertilization if soils test low to very low in P. If P is low to very low, application of 50 to 100 pounds P₂O₅/acre is suggested. Broadcasting P fertilizer prior to seedbed preparation, banding P with the seed, or broadcasting P on established grass stands are effective methods of supplying P.

NITROGEN (N). Application of 30 to 60 pounds of actual N/acre/yr is suggested for areas receiving 18 to 25 in. ave. annual pptn. As experience is gained, rates can be adjusted for soils, soil moisture conditions, and forage needs. About 3 to 4 pounds of gain per pound of N applied should be produced by properly managed yearling steers. Nitrogen prices increased substantially in 1995. Our studies on pastures fertilized and grazed for a number of years show that a N rate of 30 to 40 lbs N will give optimum returns.

In drier areas (18 to 25 in ave. annual pptn.), a single N application in April usually results in more forage produced and greater fertilizer N recovery than split April/June applications.

Urea is usually in more abundant supply and less expensive per pound of N than ammonium nitrate. However, broadcast urea can be a less effective N source because N volatilization losses can be greater. Forage yields are the same in some years and as much as 30% less in other years when fertilized with urea as compared to ammonium nitrate. Volatilization loss can be minimized if urea is broadcast on dry surfaces in cool weather when there is a good probability for receiving rain to move the urea into the soil. The optimum time for applying urea is about 4 weeks after the grass greens up. Shallow (1") drilling of urea should minimize N volatilization loss.

Liquid N fertilizers (28-0-0, 32-0-0) are mixtures of urea and ammonium nitrate. Dribbling liquid fertilizers on pastures rather than spraying results in less N loss to volatilization. Injection into the soil should minimize loss.

Anhydrous ammonia is applied to Old World bluestem by some producers. The yield response has been satisfactory. A shank spacing of 24 inches is commonly used. The power demand is high. Little or no damage to the overall stands are evident from the disturbance caused by the injection.

IRON. These grasses can become iron deficient (chlorotic, light green to yellow with white new growth) when grown on eroded soils that are limy (calcareous, caliche) to the surface. Fields or spots in fields that produced chlorotic sorghum will probably produce iron-deficient Old World bluestems. 'WW-Iron Master' Old World bluestem is tolerant of iron-deficient soils and is recommended on higher pH soils (pH 7.4-8.4).

POTASSIUM AND SULFUR deficiencies probably will not occur in these grasses in areas receiving 18 to 25 inches ave. annual pptn. If a deficiency should occur, it most likely will be on sandy, low organic matter soils. Soil tests will give an indication of deficiencies of these elements.

Factors influencing forage quality include stage of growth, species of grass, and soil fertility. All warm-season grasses, including Old World bluestems, are highest in forage quality (digestibility and crude protein) at the start of growth and decrease in quality as the season progresses. After mid-July, forage quality declines rapidly until fall, after which time forage quality remains rather constant. Generally, forage from Old World bluestems meets or exceeds recommended requirements for animal growth from May to July 15, but protein supplementation may be necessary during other periods, especially with younger animals.

A study of 8 Old World bluestems at Woodward, OK showed that digestibility and crude protein was higher in Iron-Master than in Caucasian. WW-Spar was intermediate in these characteristics. In a series of harvests from heading to seed ripe stages, leaves of 8 Old World bluestems averaged 63% digestible and 8% crude protein. Stems averaged 55% digestible and 4.5% crude protein.

Spring burning is an important management tool that can be used to remove substantial amounts of standing dead vegetation or to control undesired winter annuals. However, burning every year is not recommended. Annual spring burning resulted in 6 to 30% less forage production in our studies.

YEAR ROUND GRAZING. Yearling steers grazing Old World bluestems gained between 0.2 to 0.5 pounds/steer/day in winter, and 1 and 2 pounds/steer/day during the summer season (Table 1). The studies used a 2-pasture system with steers rotated monthly during the growing season and with access to both pastures in winter. The grass was fertilized in April with 60 pounds N/acre/yr. Steers were stocked in Dec. as 500 pound weaners. Dormant season grazing was supplemented with 1.5 pounds of 41% protein/ steer/day. Steer gain per acre was 3 to 4 times greater than gain on native range. Gain per steer was slightly less than on native range. Steer gains were similar among Caucasian, Plains, and WW-Spar bluestems.

	GRAZING SEASON
	Winter(Dec-Mar)	Summer (April-Sept)	Dec - Sept.
	Avg. (Range)	Avg. (Range)	Avg. (Range)
Daily gain lbs/steer	0.4 (0.2-0.6)	1.7 (1.5-2.1)	1.2 (1.0-1.5)
Seasonal gain lbs/steer	42 (20-80)	220 (180-250)	260 (230-300)
Total gain lbs/acre	30 (20-50)	150 (120-170)	180 (140-220)
Stocking rate acres/steer/yr	1.5 (1.0-2.0)	2.0 (1.5-3.0)	1.7 (1.5-2.0)

We do not have research on cow-calf operations on Old World bluestem. A producer near Woodward has a cow-calf operation running year round on Old World bluestem. This producer uses a stocking of 4 to 5 acres/cow, an 8 pasture rotation with pastures of 30 to 50 acres, applies 30# N/yr, and hays excess forage in early summer.

GROWING SEASON GRAZING. Steer gain should be similar to that shown in Table 1 for summer grazing. A suggested stocking rate is 1.2 acre/stocker. Start grazing when there is 4 to 6 inches of new growth (late May - early June).

COMPLEMENTARY GRAZING WITH OTHER FORAGES. Old World bluestem (OWB) is at its highest quality and is most productive in June and early July. Production efficiency can be improved if all of the grazing is concentrated in this period. Complementary forage systems that accomplish this include:

Using these systems, steer gains on OWB were 2 to 2.5 lbs/head/day and 200 to 250 lbs/acre. Stocking rate was 2 steers per acre. Grazing began around the first week in June when the grass was 6 to 8 inches tall and growing rapidly. The OWB is grazed heavily and steers are removed in late July after about 50 days of grazing.

Table 2. Complementary grazing of native sandhills pasture and Old World bluestem.

These grasses have high potential to respond to irrigation if adequate fertilizer is applied. Yearling steer gains up to 1300 pound/acre have been attained with rapid rotation systems on well-managed irrigated stands. Most managers can obtain around 800 pounds gain/acre from such systems. Fertilization with 200 to 300 pounds/acre of actual N is needed.

The Old World bluestems can be used for hay production. One cutting per year is typical under dryland conditions. Yields should range from 1 to 2 tons/yr.

Nitrogen fertilization at a higher rate than under grazing is needed since N is hauled off. About 60 pounds of actual N/acre/yr is suggested. Protein content should range from 9 to 12% if hay is cut soon after heading.

Old World bluestem stands can be maintained if late summer haying or repeated heavy grazing in late summer is avoided. Delaying spring grazing until leaf length reaches 4 to 6 inches will keep plants vigorous. Removing animals in late August and September to allow some regrowth and give roots an opportunity to grow in preparation for winter is especially helpful. This allows plants to over winter, particularly during dry periods, and have sufficient healthy roots to initiate spring growth.