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Kaiser, C.J. and M.E. Heath. 1990. Big trefoil: A new legume for pastures on fragipan soils. p. 191-194. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.

Big Trefoil: A New Legume for Pastures on Fragipan Soils

C.J. Kaiser and M.E. Heath

    1. Taxonomy
    2. Morphology
    1. Adaptation
    2. Nutritive Value
    3. Diseases and Pests
    4. Cultivars
  6. Table 1
  7. Fig. 1


Big trefoil, Lotus uliginosus Schkuhr (Terrell 1986, Tutin et al. 1964-76, Heath 1970), introduced over 100 years ago into the United States (Henson et al. 1962), is of European origin from the Mediterranean northwards to 60°N. Naturalized in the Pacific Northwest big trefoil is used for pasture, hay and seed production. It has shown good adaptation on wet soils in Georgia, North Carolina, and Florida (Heath 1970) and is also grown in Minnesota, Indiana, and Illinois (Fig. 1) as well as Australia and New Zealand.



Big trefoil, Lotus uliginosus has been also described as L. major, and L. pedunculatus Cav. (Heath 1970). The L. corniculatus group (Tuten et al. 1964-76) includes twelve species, among them are uliginosus, pedunculatus, and corniculatus.

Big trefoil should not be confused with Birdsfoot trefoil (L. corniculatus Cav). Birdsfoot trefoil is extremely variable and easily confused with big trefoil. Seed used for commercial plantings of birdsfoot trefoil produce plants that differ widely. Under natural conditions regional strains of birdsfoot trefoil have developed. These strains of birdsfoot trefoil have been given cultivar designation. For the most part shape of leaflets, habit, and size of birdsfoot trefoil plants have been the basis of differentiation, but in some cases color and number of florets per flower umbel have been recognized.

The florets of big trefoil are brilliant yellow. Two characteristics distinguishing the species L. uliginosus Schkuhr and L. corniculatus Cav are the rhizomes and number of florets per flower umbel (McKee and Schoth 1941, Tutin et al. 1964-76). L. uliginosus Schkuhr usually has eight to twelve florets per flower umbel (rarely 5 to 7); rhizomes are spreading; 2n = 12. L. corniculatus Cav. has five florets per flower umbel, (sometimes 6, and rarely 7); rhizomes are not spreading except for the cultivar 'Kalo'; 2n = 24.

The variety 'Grasslands Maku' developed at Palmerston North, New Zealand (Armstrong 1974) is an intraspecific hybrid tetraploid (2n = 4x = 24). Bees are essential for the production of big trefoil seed. Plants are incapable of spontaneous self pollination (Silow 1930), but are self-fertile after artificial self pollination. Big trefoil plants cross pollinate readily. Big trefoil, like birdsfoot trefoil, is a long-day plant requiring a 16-hour photoperiod for complete floral induction.


Big trefoil is a perennial having fine stems, relatively large leaves, shallow rooted with vigorous underground stems or rhizomes (Armstrong 1974). Instead of big trefoil plants thinning as they get older and the stems getting coarser as with alfalfa, the rhizome keeps sending up new leafy stems, and as a result the stems stay fine. Big trefoil is not tall growing. The plants grow from 0.6 to 1.0 m tall, but with the fine stems it does not stand up too well unless supported by vigorous growing grasses (Howell 1948). The crown is below ground. Shading is avoided in tall grass by rapid stem elongation to elevate the leaves above the shade canopy. High temperatures (22°C) are necessary for rapid growth (Lambert and Boyd 1974). Maximum growth of big trefoil occurs in summer and early fall.



Big trefoil's greatest promise is on wet, poorly drained soils in the humid areas of the United States. Once the plants are well established they can withstand surface flooding. They have been observed to survive on soil, where the rainfall averages 1020-1170 mm annually. These soils are often water-logged in winter and very early spring. There is little, if any, lasting snow cover during winter. Diurnal temperatures frequently fluctuate-above and below freezing. Under these conditions big trefoil survives where other tap rooted pasture legumes do not.

Soil fragipans restrict moisture movement as well as plant root depth development. Fragipans were formed under low pH in humid areas (Zachary and Ulrich 1965). Plant roots will not penetrate the fragipan unless through a cleavage or crevice.

Big trefoil is adapted to fragipan soils maintained in tall fescue (Festuca arundinacea Schreb.) pastures (Heath 1970, Kaiser and Faix 1982). When big trefoil is grown alone, much winter killing, and plant damage has been observed compared to no winter damage when grown with an adapted perennial cool season grass in southern Illinois and Indiana. Big trefoil is grown in the Pacific Northwest USA on wet, poorly drained soils and upland areas with high rainfall. It is not as winter-hardy as birdsfoot trefoil (L. corniculatus), which may restrict its adaptation in northern areas where birdsfoot trefoil is productive.

Big trefoil appears to be well adapted in the "tall fescue belt" (Kaiser and Cate 1974). A study was conducted at the University of Illinois Dixon Springs Agricultural Center to observe big trefoil in tall fescue sod grazed by sheep. Big trefoil was no-till seeded on April 3, 1976 at 1.12 kg/ha into six established tall fescue sheep pastures on fragipan soil. The recommended seeding rate for big trefoil is 3.36 kg/ha. No-till seeding was made using the John Deere 1500 power till drill. Seed was inoculated using a commercial preparation. Pastures were mob grazed by sheep annually to permit big trefoil seed production. Pasture fields were 2.5 ha in size. Plant spread (creeping) and percent stand measurements were made five years after planing in the fall of 1981. Individual plants were selected to determine the rate of creeping. Average spread of individual plants after five years was 457 rnm. The range in spread was from 432 to 508 mm. Big trefoil plants appeared to spread at the rate of 76 mm per year into dense tall fescue sod.

Big trefoil appears to be a long-lived legume. Percent stand increased in each of six growing seasons at Dixon Springs, Illinois (Kaiser and Faix 1982). Each year the plants appeared to become more vigorous and to establish more rapidly in moist areas and grass waterways. Big trefoil tolerated standing water in grass waterways. It appeared very aggressive in the dense tall fescue sod indicating shade tolerance. Big trefoil can tolerate lower levels of soil fertility and higher acidity than white clover (Trifolium repens) and is one of the slowest legumes to establish (Armstrong 1974).

Inoculation is an absolute requirement for big trefoil establishment. Big trefoil requires a specific inoculatum for N fixation. It will not become nodulated with cultures used for birdsfoot trefoil or other legumes. The fast growing acid tolerant strain of Rhizobium loti holds a competitive advantage in nodulation of big trefoil over the slower growing acid sensitive strain Boradyrhizobium sp. Lotus (Cooper et al. 1985). Best stands of big trefoil were established when up to five times the manufacturers inoculation recommendation of Rhizobium lupini was used (Lowther and Littlejohn 1984).

Nutritive Value

The nutrient value of big trefoil is believed to be equal to birdsfoot trefoil. Several feeding studies with dairy and beef cattle have shown big trefoil to be equal to alfalfa when cut for hay in the midbloom stage. Percent crude protein of big trefoil pasture (8-12 mm tall) was 28.5 in an Oregon test (Howell 1948). Close grazing by sheep over an extended period of time has not reduced stands. It withstands grazing by deer and elk and has also been tested in pastures used by geese and widgeon.

The presence of 3-nitropripronic acid (3-NPA) in big trefoil has been a concern to livestock producers. Several phenotypes grown in Illinois were evaluated (Kaiser et al. 1983). All phenotypes evaluated were non-toxic to livestock.

Big trefoil is a non-bloating legume (Jones et al. 1970). The leaves and stems contain condensed tannins which render forage proteins insoluble by precipitating the soluble leaf proteins that form foams during ruminant digestion, thus preventing bloat.

'Grasslands Maku' big trefoil contains 20-30 g of condensed tannins/kg of dry matter when grown in high fertility soils and 70-80 g of condensed tannins/kg of dry matter when grown in acid low fertility soils (Berry and Forss 1983). High condensed tannin concentration of big trefoil grown under low acid and low soil fertility, conditions reduced live weight gains and wool growth in sheep (Barry 1985), however, increasing levels of condensed tannins concentration conferred a beneficial effect on nutritive value by increasing duodenal N retention (Barry et al. 1986). A compromise concentration of condensed tannins which will give adequate animal performance and confer bloat resistance is 30-40g of condensed tannins/kg of big trefoil dry matter. This ratio is best achieved when big trefoil is grazed with a companion grass.

Diseases and Pests

Four diseases have been reported in big trefoil (Wells 1953). The blackpatch fungus (causal organism of the blackpatch disease) results in an aerial blighting of leaves and stems during warm weather from April through October. Rhizoctonia solani (causal agent of summer blight) produces a rapid aerial blighting of leaves and stems during hot, humid weather from May through September. Sclerotium rolfsii (causal organism of southern blight) was first recognized as part of the big trefoil blight complex at Tifton, Georgia in July, 1953. This fungus attacks leaves and stems where free moisture is present during hot humid weather. Colletotrichum truncatum (causal organism of big trefoil anthracnose), which causes leaf spot and leaf and stem blight, was first recognized as a part of the big trefoil blight complex at Tifton in July of 1953. Anthrancnose was reported (Kaiser 1983) at Dixon Springs, Illinois in 1982.

Lygus bugs (Lygus spp.) are a serious threat to big trefoil seed production in Oregon. They suck juices from big trefoil plants causing blasted buds, blossom drop, and shriveled seed. Heavy infestations of lygus bugs during flowering can cause almost complete failure of plants to form pods.

Big trefoil plants are sometimes killed or severely injured by moth larvae Walshia spp. Individual plants may show damage caused by the moth larvae, or the damage may appear in patches containing numerous plants.

The potato leafhopper, a troublesome pest on alfalfa, also may cause damage to birdsfoot trefoil (Monteith et al. 1929). However, no damage was noted on big trefoil by workers in the "tall fescue belt" (Heath 1970, Kaiser and Faix 1982).


Six big trefoil cultivars have been used in the U.S. (Table 1). 'Beaver', 'Columbia' and `Marshfield' (Billings and Swanson 1974) were planted in the northwest (Fig. 1). 'Grasslands Maku' (Kaiser and Faix 1982) and 'Kaiser'(Heath 1970) were shown to be suitable for southern Illinois. `Border' is farm selected from Oregon near the Washington border and not officially recognized as a cultivar.


Big trefoil may be best suited as a pasture legume in poorly drained soils in humid areas. Naturalized ecotypes of big trefoil appear to be strongly perennial and fit the environmental model of hill land fragipan soils (Heath 1970) in the "tall fescue belt" where it competes aggressively with tall fescue. Big trefoil is found growing in marshes and wet lands of Europe (Tutin et al. 1964-76). It compares favorably to alfalfa and does not cause bloat in ruminants. It appears to be a very efficient supplier of nitrogen once nodulated. Big trefoil appears to possess the required characteristics for a companion legume in perennial cool season grass pastures. It's greatest promise is on poorly drained and fragipan soils, grassed waterways and wet lands.

Our best estimate is that 5000 ha of a big trefoil (Swanson 1988) are now grown (1988) in the U.S. A major part of this area has been planted by the USDA Forest Service and State Fish and Wildlife services of Oregon and Washington for utilization by deer and elk in logged over areas. Deer and elk graze on big trefoil in preference to young tree seedlings, thus allowing the young seedlings to become established. Recent research in Europe, New Zealand, Australia and the United States suggest that big trefoil has the potential for use on wet land sites, fragipan soils and humid areas for cattle and sheep pastures as well as for wildlife.

The advantages of big trefoil are: it spreads by rhizomes, is long-lived in perennial grass pasture, will tolerate acid soil conditions, is adapted to wet or poorly drained soils, nutrient value compares favorably to alfalfa, and it does not cause bloat in cattle or sheep.

The disadvantages of big trefoil are: it lacks drought resistance, is not as winter-hardy as birdsfoot trefoil, requires a specific inoculum (different from birdsfoot trefoil), has less seedling vigor than alfalfa and red clover, and is not tall growing.


Table 1. Big trefoil cultivars.

CultivarOriginator Merchandiser
Beaver Oregon State, USDA Public variety
Border Oregon-Washington Public varietyz
Columbia Oregon State, USDA Public variety
Grasslands Maku New Zealand, DSIR Public variety
Kaiser Purdue, USDA Public variety
Marshfield Washington State, Oregon State, USDA Public variety
zNot a recognized cultivar

Fig. 1. Big trefoil-producing areas of the U.S.

Last update August 26, 1997 by aw