DIVISION OF AGRICULTURE R E S E A R C H & E X T E N S I O N University of Arkansas System Agriculture and Natural Resources FSA3137 Annual and Perennial for Arkansas

ruminants. Not all clovers cause bloat, Dirk Philipp Introduction and the problem is unlikely even Assistant Professor ­ Clovers and other are with bloat­inducing types unless the Animal Science highly desirable in proportion of in the stand is and meadows. First, legumes greater than 50 percent. A few clovers John Jennings are able to obtain nitrogen from air synthesize estrogen­like compounds Professor ­ through their symbiotic relationship called phytoestrogens that can cause Animal Science with Rhizobium bacteria and, there­ reproductive problems in livestock, especially sheep. Sheep should not be fore, are not dependent on nitrogen grazed on these clovers during the Paul Beck . The fixed nitrogen is breeding season. On rare occasions, Professor ­ primarily used to support clover Animal Science growth, but parts of it become avail­ some clovers become infected with able to neighboring grass when a that causes “slobbers” or clover tissue dies. A second valuable excessive salivation in cattle and role of clovers is to increase forage . If this occurs, animals should quality of pastures, hays or . be removed from the offending forage. Legumes are higher in crude protein and digestibility than most grasses In summary, clovers are beneficial commonly used in Arkansas. Animals additions to many forage programs usually consume diets higher in because of improved forage growth quality than grass alone when pas­ distribution, increased forage yield, tured on grass/ mixtures or increased forage quality and reduced fed grass/legume hays. As a result, nitrogen fertilizer costs. These animal performance often improves benefits lead to increased animal when a clover is included in pastures, performance and profitability of the even though total forage yield may not livestock enterprise. Winter annual increase. Adding clovers to endophyte­ clovers are considered better adapted infected tall fescue pastures also to and environmental conditions improves performance of cattle by in southern Arkansas than perennial diluting the toxicity of the endophyte. clovers. Perennial clovers are slower A third advantage is that clovers can to establish than annuals and are not help even out the forage supply over very long­lived in the hot, humid the season by providing Coastal Plains region of southern Arkansas Is grazing time when other are Arkansas. Our Campus not as active or dormant. In this fact sheet, the characteris­ Clovers are implicated in some tics of annual and perennial clovers health problems for livestock. Many are described including procedures for

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University of Arkansas, United States Department of Agriculture, and County Governments Cooperating excellent cold tolerance. Like white clover, it will go Perennial Clovers dormant during the summer heat, but it later than white clover during a more defined period. Red White Clover clover is not tolerant of frequent close grazing and is White and ladino clover are the same species. best suited to hay meadows or paddocks that are The only difference is that ladino­type cultivars have rotationally stocked. Red clover is reasonably shade­ been selected for a taller and higher yields. tolerant and is particularly well­suited to mixtures These traits make ladino more suitable for hay than with tall grasses like tall fescue and dallisgrass. It common or wild­type white clover (also called Dutch has the best seedling vigor of any perennial clover, white clover). Common white clover grows very close which makes it a good choice for overseeding into to the ground and is perfectly adapted for use under cool­season perennial grasses. Natural reseeding is continuous grazing systems or for livestock species unlikely to be sufficient to maintain stands. It has that graze close to the ground, such as sheep or excellent forage quality and contains a higher propor­ horses. It is difficult for animals to kill common tion of bypass protein than most other forages. As a white clover through overgrazing. result, cattle sometimes perform surprisingly well on this forage. White clover is cold­tolerant throughout the state and is among the most tolerant clovers for wet Red clover can cause bloat. It contains phytoestro­ soil conditions. However, it will not tolerate summer gens that can impair the fertility of sheep but is not heat and drought very well. In northern parts of the likely to cause fertility problems if grown in mixed state, plants go dormant during summer. In southern grass/legume stands. Red clover is the clover most parts of the state, they likely will die in summer. commonly implicated in cases of slobbers, but this is However, common white clover is a prolific reseeder, an unusual problem that should not discourage use of so stands will probably regenerate each fall. White the clover. clover is generally a very good reseeder, but some ladino types are poor reseeders. White clover is Planting rate for red clover is 10­12 lb/acre. shade­tolerant but can be shaded out of mixtures ‘Cherokee’, ‘Kenland’, ‘Kenstar ’ and ‘Redland II’ are by taller grasses if canopy height is not carefully proven varieties for Arkansas. There are many others managed by hay cutting or grazing management. that may also work well. It does not generally persist well in mixtures with tightly sodded grasses like bermudagrass or bahia­ Alsike Clover grass. White clover spreads laterally via aboveground stems called stolons. Bloat potential of white clover Alsike clover is better suited for the northern tier is considered high. counties of Arkansas than for more southern ones. It has better tolerance of wet and acid than most Planting rate is 2­3 lb/acre. Proven white clover clovers. Alsike clover is not tolerant of shade. It varieties for Arkansas include ‘Osceola’, ‘Louisiana should not be used for pastures because it has a S­1’, ‘Regal’, ‘Patriot’ and ‘Durana’, and there are tendency to cause photosensitization, or sun scald, in many newer varieties that may also work well. When that livestock species. Seeding rate is 4­6 lb/acre. testing newer, unproven varieties, producers should start by seeding a small area to check for local adaptability. Sweetclover The two sweetclover species (yellow and white) are not true clovers. These are biennial plants that Red Clover reseed well to form “perennial” stands. Sweetclover is Red clover is classified as a perennial but is extremely tall, up to 8 feet. They are winter­hardy generally considered to act like a biennial with a throughout Arkansas and tolerant of drought but do useful stand life of only two to three years. In south not tolerate acid soils. Sweetclover contains a bitter Arkansas, it often acts like an annual and does not compound called coumarin which is extremely survive through extremely hot summers. It has distasteful to animals. In moldy sweetclover hay, coumarin is converted into the toxic compound dicumarol which causes sweetclover poisoning in Arrowleaf Clover cattle. Low­coumarin sweetclover varieties are avail­ Arrowleaf clover is a tall clover that holds its able (white ‘Polara’ and yellow ‘Norgold’). Planting quality well for a longer period of time than most rate is 10­15 lb/acre. annual clovers. It is among the latest­maturing clovers and may produce forage into June. Its late maturity makes it a good match to be grown with annual ryegrass. Arrowleaf clover will germinate at Annual Clovers cooler temperatures than crimson clover. It is not In Arkansas, all the annual clover species tolerant of infertile, acid soils. Animals rarely bloat perform best as winter annuals, meaning that they on arrowleaf clover. Periodic grazing to a height of germinate in fall, grow through the winter, 2 to 4 inches promotes new growth and reduces plant and set seed in spring or early summer and then die. disease outbreaks. The purplish­red color of arrowleaf For some species, the seeds that were naturally pro­ clover is a symptom that the plant is stressed duced will continue the cycle in the following year, by something such as nutrient deficiency, insects, while others must be replanted every year. Annual diseases or weather. Arrowleaf reseeds well under clovers can be overseeded onto dormant warm­season grazing, but much of the seed it produces is hard, grasses, either alone or in combination with small which makes year­to­year stand regeneration some­ grains and annual ryegrass. what unpredictable. Regrowth (and reseeding) should not be expected after a hay crop is harvested. Plant­ Because annual clovers complete their life cycle ing rate is 5­7 lb/acre. Standard varieties are ‘Yuchi’ each year, they must be re­established from seed. and the disease­tolerant ‘Apache.’ The clover stand can be re­established either by replanting each year or relying on natural reseeding. Reliance solely on natural reseeding increases risk of Ball Clover establishment failure, because the producer depends Ball clover is another low­growing clover with on good conditions in late spring for clover seed pro­ excellent tolerance of close grazing. It also has good duction as well as in the fall for seed germination and tolerance of wet, clay or loam soils. Ball clover toler­ seedling development. For natural reseeding to occur, ates lower soil acidity than crimson clover. Ball clover grazing and hay harvest should be managed to allow has poor cold tolerance and is best suited to southern some of the clover to mature in late spring for seed Arkansas. Bloat is a serious concern with this clover, production. and it should not be used in pure stands. Reseeding capability under grazing is excellent because flowers are produced close to the ground. Much of the seed is Crimson Clover hard. Seeding rate is 2­3 lb/acre. Improved varieties Crimson clover is the standard against which are not available. other annual clovers are compared in Arkansas. It has the best seedling vigor of the annual clovers. It is the earliest to mature of the commonly used annual Berseem Clover clovers, flowering in early April in south Arkansas Berseem clover is a relatively new addition to and about three weeks later in northern regions. This the list of clovers that can be grown in Arkansas. limits its usefulness as a hay crop, but it is widely Older varieties lacked enough cold tolerance for even used to overseed bermudagrass. Crimson clover is not southern tier counties. The newer variety ‘Bigbee’ tolerant of wet, poorly drained or alkaline soils but has enough cold tolerance to be worth risking in the has good tolerance to soil acidity. Bloat is usually not southern half of the state, although it will likely a severe problem but can occur. Its reseeding poten­ winterkill in a severe winter. It is not suitable for tial is fair if heads are allowed to ripen and if clover northern Arkansas. Bigbee berseem clover has weevils do not destroy the seeds. Seeding rate is 10­ excellent tolerance of wet soils and poor drainage. It 30 lb/acre. ‘Dixie’ is the standard variety. ‘Tibbee’ is does not tolerate acid soils well, doing better on near­ another good forage variety. neutral and slightly alkaline soils. Berseem clover requires good soil fertility and will respond to boron soils, but does not like acid or wet soils. Overton rose fertilizer. It matures about a month later than crim­ clover is a late­maturing clover with good reseeding son clover. Bloat is very unusual on berseem clover ability if heads are allowed to mature. It makes a . Berseem performs well under grazing if not high proportion of hard seeds. In Hope, Arkansas, it grazed closer than 3­4 inches. Bigbee has potential to appears to be resistant to clover weevils. Rose clover reseed itself but is likely to be undependable. Plant­ tolerates grazing well. Bloat is not usually a problem ing rates are 10­20 lb/acre. when grazing rose clover. Seeding rate is 15­20 lb/acre.

Hop Clover Subterranean Clover There are two species of hop clover, large hop clover and small hop clover. Hop clovers are actually This clover is so named because it buries its seed medics, not true clovers, and are closely related to pods underground. This trait results in excellent . Both hop clovers are naturalized throughout reseeding potential. Subclover is a low­growing clover Arkansas and are most often found on infertile, acid, with excellent tolerance to close grazing and continu­ unproductive ground. Hop clovers do not compete well ous stocking management. It has poor cold tolerance with other forages when fertility is good. Dry matter and is best suited to use in the southern half of production is low, maturity is very early and plants Arkansas. Subclover has a relatively high rate of do not regrow well after being grazed. As a result, N fixation under ideal conditions. It is too short in hop clover is rarely planted in pastures, but it can stature to contribute yield to hay crops but can be contribute some forage for grazing and limited used to fix N for hay crops. It is a mainstay of the amounts of recycled nitrogen. Natural reseeding Australian grazing industry, and most available vari­ capability is excellent. Planting rate is 3­4 lb/acre. eties were developed there. A limiting factor to its Improved varieties are not available. usefulness in Arkansas is that light August rains often trigger seeds to germinate too early, before ade­ quate moisture is available for growth. As a result,

Persian Clover seedlings die. Harder­seeded varieties are being intro­ duced into this country in an attempt to address this Persian clover is one of the best clovers for wet, problem. This is the most shade­tolerant of the poorly drained soils. It does not tolerate acid soils, clovers and tolerates some wetness and soil acidity. and cold tolerance is poor. It is best suited for south­ Subclover can cause bloat. It is the clover most likely ern Arkansas. Persian clover is one of the most to be implicated in phytoestrogen fertility problems in dangerous clovers for causing bloat and should never sheep. However, most newer varieties have been bred be grazed if stands are more than 50 percent clover for lower phytoestrogen content in order to reduce unless a bloat preventative is being fed. It tolerates this problem. Planting rates are 10­20 lb/acre. close grazing well and has excellent seed production, Varieties with proven track records for Arkansas are but a high proportion of hard seeds can make stand ‘Mt. Barker ’ and ‘Denmark’, and new varieties are regeneration unpredictable from year to year. Seeding continually being introduced from Australia. rate is 3­5 lb/acre. ‘Nitro’ is an available improved variety.

Clover Establishment Rose Clover The first step in successful establishment of Rose clover is a drought­tolerant species that has clovers is proper site selection. Factors such as soil been widely used in California for years. A newer texture and drainage should be considered when variety, ‘Overton’ (also often referred to as R18), was matching a clover species to a specific site. Select a developed by Texas A&M University and has better site well in advance so weed management and adaptation to the rainfall and humidity conditions in improvements in soil fertility and pH can take place. Arkansas than do other available varieties. Rose Weeds should be suppressed using a herbicide with clover is tolerant of poor soil fertility and alkaline short residual activity such as 2,4­D or Weedmaster. Soil samples should be collected and analyzed so that Seeding in warm­season grass can be done as any required phosphorus, potassium or lime can be early as October 1 in northern Arkansas, otherwise added well in advance of planting. (Refer to FSA2121, October 15 to November 15 when cool nighttime Test Your Soil for Plant Food and Lime Needs, for temperatures (50 to 60 degrees F) slow grass growth information on soil sampling and analysis.) Soil pH and reduce competition. Because fescue grows vigor­ should be near neutral (> 6.0). When clovers are to ously in the fall, fescue sod must be grazed short or be planted in acidic soils, lime should be applied at lightly disked to reduce competition before interseed­ least 6 months before seeding to allow the soil pH to ing clovers. adjust. Most clovers respond to improvements in soil fertility. Potassium is a very important nutrient for Late­maturing clovers (red or arrowleaf) grown clovers, and attention should be paid to supplying with perennial warm­season grasses will reduce late adequate amounts according to soil test recommenda­ spring growth of the grasses. Clovers may be shaded tions. Phosphorus should also be applied according to out if grasses are allowed to outgrow them, but may soil tests. Many clover species will respond to boron improve forage quality over grass alone. Early fertilization at 1­2 lb/acre every one to two years, (crimson) and medium­maturing (berseem and rose) especially when grown on sandy soils. clovers can allow earlier grazing of perennial warm­ season grass pastures and will supply nitrogen to the Nitrogen fertilizer application to clovers should be grasses under proper management. Late­maturing avoided as much as possible. When abundant soil N clovers grown with cool­season grasses (tall fescue is available, clovers will use that instead of fixing or small grains) can lengthen the grazing season, their own N, which reduces one of the benefits of improve forage quality and reduce the toxic effect of using clover in the first place. Also, when N is applied fungal endophytes found in fescue. Low­growing or to grass/clover mixtures, the grass usually responds prostrate clovers are generally more grazing tolerant faster than the clover, which can lead to excessive than upright­growing clovers. Preferred site, soils, shading of clover and its loss from the stand. If N and management of many common clovers fertilizer must be applied to keep grass productive, are shown in Table 1. rates should be kept to 30 lb N/acre or less at each application. Many clovers produce a percentage of “hard” seeds that do not germinate immediately after plant­ Clovers can be established by broadcasting or ing. The seedcoat of hard seed is impervious to water, drilling seed into a grass sod or following tillage. which delays germination for long periods. Hard seed Establishing clovers by broadcasting following tillage may survive passage through the digestive tracts of increased the clover stand counts by 41 percent in animals and can remain viable in soil for 30 years. southern Arkansas. Stand counts were only 50 per­ Delayed germination by hard seed of annual legumes cent for clovers broadcast onto a mixed grass sod but grown in harsh environments helps maintain stands increased to 91 percent with tillage. Seed should be from volunteer seedlings when conditions are not planted shallow. It can be drilled to a depth of 1/4 favorable for seed production in a particular year. to 1/2 inch or broadcast. Seeding rates should be Clover species that produce a high percentage of hard increased by 20 to 25 percent if clovers are estab­ seed provide more dependable volunteer stands than lished by broadcasting seed. Clover seed should be those that produce more soft seed. inoculated with the correct species of before planting to ensure good potential Good stand establishment and forage production (see FSA2035, Forage Legume Inoculation, for depend on a variety of factors including soil fertility, detailed information about legume inoculation). moisture, pH, seed­to­soil contact and inoculation of seed with nitrogen­fixing bacteria. (Refer to FSA2035, When interseeding clovers into a sod, it is Forage Legume Inoculation, for information on inocu­ important to remove existing forage to a height of lation of legumes.) 3 inches or less. to

Drainage Good Good Poor Fair Good Poor­Good Good Moderate Excellent Poor Fair Good Arkansas in to sod. Characteristics in Loam Loam Loam

to to to to to to to to

Loam Loam Loam Loam Loam Loam Loam Soil

grown Texture Loam Loam

Clay Clay

seeded Loam Clay Loam Clay Loam Clay Sand, or Loam Clay Loam Clay Clay Loam Sand, or Loam Clay Sand Silt Sandy Silt when Preferred pH 15 6.0

6.0­8.0 5.8­7.0 6.0­8.0 6.0­8.0 6.0­7.0 6.0­7.0 7.0­8.0 6.0­7.0 > 6.5­8.0 5.8­7.0 commonly

November Bloat (medium) (medium) (medium) (medium) (medium) (high) (medium) (medium) (high) (low) (low) and

clovers Potential 15 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes October May May June

May­ May Date

perennial Flowering May­Sep Mid June May­Sep Late April Mid April Early May­Sep Early April Mid Early Early between and or Arkansas annual Adaptation Statewide Statewide Northern Statewide Southern Southern Statewide Statewide Southern Southern Statewide seedbeds for

prepared Relative Maturity Late Late Late Medium Medium Medium Medium Early Medium Medium Late in Characteristics 1

Cold Plant Good Good Good Good Fair Fair Good Medium Poor Good Good Tolerance requirements November

and site 1 Ability High Low Medium High Medium Medium Low Low Low High High Reseeding and

September 3­5 3­5 2­3 5­15 4­10 8­10 Rate 10­12 15­20 12­15 15­20 12­15 (lbs/A) Seeding between

Uses characteristics planted Common Grazing/ conservation Hay/grazing Hay/grazing Grazing Grazing Grazing Grazing Grazing Grazing Grazing Hay/grazing be Plant a should 1.

Clover

Clover Clovers Sweetclover Red Rose Alsike Subterranean Persian White Crimson Berseem Ball Arrowleaf Table a

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DR. DIRK PHILIPP is an assistant professor ­ animal science Issued in furtherance of Cooperative Extension work, Acts of May 8 located at the University of Arkansas in Fayetteville. DR. JOHN and June 30, 1914, in cooperation with the U.S. Department of JENNINGS is a professor ­ animal science located in Little Rock. Agriculture, Director, Cooperative Extension Service, University of DR. PAUL BECK is a professor ­ animal science located at the Arkansas. The Arkansas Cooperative Extension Service offers its Southwest Research and Extension Center in Hope. All are with programs to all eligible persons regardless of race, color, national the Department of Animal Sciences, University of Arkansas origin, religion, gender, age, disability, marital or veteran status, or Division of Agriculture. any other legally protected status, and is an Affirmative FSA3137­PD­8­13N Action/Equal Opportunity Employer.