Persian clover


Persian clover (Trifolium resupinatum) is an annual pasture legume, growing over the period autumn to spring. It can be used as either a special purpose forage crop or a self-regenerating pasture. Regrowth after grazing or cutting is excellent, and it has a high nutritive value as pasture or hay. Two spring hay cuts are possible with the later maturing varieties. Waterlogging tolerance is high. It can be sown with oats or tetraploid ryegrass for greater winter production and to reduce the risk of bloat. In recent years there has been a greater interest in using Persian clover as a forage legume break-crop in dryland cropping rotations. Traditionally Persian clover has been used as a self-regenerating pasture in irrigated and dryland situations, often in mixtures with sub. clover, to extend spring production following sub. clover senescence. It also has a role as a soil renovator following landforming.


Persian clover is a native of Turkey, Afghanistan, Portugal, Greece, Iran and Iraq. It was introduced to South Australia in the 1950s and grown commercially in the early 1970s. It has become a valuable species for temperate pastures of southern Australia.


There are seven commercial varieties of Persian clover available in Australia. The varieties and their characteristics are listed in Table 1. Varieties differ greatly in their maturity, their susceptibility to disease and their adaptation to different environments. Persian clover varieties that are soft-seeded or have no hard seed are sometimes sold under the name Shaftal or Giant Shaftal clover. However, this is incorrect as ‘Shaftal’ is the name of a less productive species, Trifolium clusii (annual strawberry clover). There are two main subspecies of Trifolium resupinatum: majus and resupinatum.

Trifolium resupinatum var. majus has an erect habit, thick hollow stems and large leaflets. Hard seed level is very low at one to two per cent. Flowering and maturity is mostly late. The varieties Maral, Morbulk, Laser and Lightning belong to this subspecies.

Trifolium resupinatum var. resupinatum has a more prostrate habit, thinner stems and smaller leaflets. Hard seed and seed yields are higher than majus. Flowering and maturity are mostly earlier than majus. The cultivars Kyambro, Nitro and Prolific belong to this subspecies.

Table 1. Characteristics of Persian clover varieties


Growth habit

Minimum rainfall (mm)*


Disease tolerance

Hard seed

Trifolium resupinatum var. resupinatum.

Prolific Prostrate to semi-erect 450+ Early to mid-season maturity;

Flowers 115–125 days after sowing

Tolerance to clover scorch and Phytophthora clandestina Moderate levels of hard seed
Nitro Prostrate to semi-erect 500+ Early to mid-season maturity;

Flowers 120–130 days after sowing

Resistant to clover scorch and Phytophthora clandestina High levels of hard seed
Kyambro Prostrate to semi-erect 500+ Mid-season;

24 days earlier than Maral

Tolerance to leaf rust, stem rust and clover scorch High levels of hard seed

Trifolium resupinatum var. majus

Lightning Semi-erect 500+ Mid-season flowering adapted to short growing season;

2–3 weeks earlier than Maral

Tolerance to clover scorch but susceptible to leaf rust No hard seed
Morbulk Semi-erect 500+ Mid to late season;

10 days earlier than Maral

Resistant to clover scorch; Higher seed yields than Maral; Tolerant of moderately saline soils Very soft seeded (2% hard)
Laser Semi-erect 500+ Late season;

3–4 days later than Maral

Tolerance to leaf and stem rust, clover scorch and Phytophthora clandestina No hard seed
Maral Tall erect type 600+ Late season;

Flowers 155–165 days after sowing

Very susceptible to leaf rust Very low levels of hard seed

* Minimum rainfall figures required for a high probability of achieving seed set and regeneration. Lower rainfall figures apply where regeneration is not required.


In southern NSW, early maturing cultivars of Persian clover need a minimum annual rainfall of 450 mm and proportionally more in northern NSW due to the predominantly summer rainfall pattern. It is important therefore, that the minimum rainfall required is increased as the proportion of summer rain increases. In areas with summer rain, it is also necessary to sow varieties with a high level of hard seed, where regeneration is required. Soft seeded varieties, such as Maral, Laser and Lightning, will germinate with summer rain, then die in subsequent dry conditions. These softer seeded varieties are more suitable as forage legume break crops. Early maturing varieties are best suited to low rainfall (450–550 mm) areas with a shorter growing season. Later maturing varieties require late spring/early summer rainfall or irrigation for late spring growth and seed set.


In NSW, Persian clover is adapted to a range of soils from clay loams to heavy clay soils. Best growth is on alkaline soils, but it will grow satisfactorily on soil with a pH (Ca) range of 5.0 to 8.0. A great advantage is that it has excellent tolerance of waterlogging and prefers soils with a high clay content. In irrigation areas good surface drainage is required to prevent scalding in early autumn and late spring. Growth on land-formed cut areas is often superior to other clovers.

Persian clover has moderate tolerance of salinity, being better than sub. clover but worse than balansa clover and lucerne.



Persian clover has a very small seed (800,000–2,000,000 seeds/kg) compared with sub. clover (150,000 seeds/kg). To ensure the best production, a minimum plant population of 100 plants/m2 is required. Assuming 30 per cent establishment, at least 4–5 kg/ha of seed is needed in dryland sowings and 6–8 kg under irrigation (see Table 2). Seeding rates can be reduced to 2 kg/ha where there is a fine seed bed and seed placement is likely to be between one centimetre and the soil surface. If used as a one year forage legume break-crop, Persian should be sown at higher rates to maximise early herbage production and weed competition.

Irrigated sowings on well-drained layouts can commence in early February. Early irrigated sowings can allow two grazings before winter. Dryland sowings can be carried out in April to mid-May, but growth from later sowings is poor because of low winter temperatures. Best results are obtained by sowing no deeper than one centimetre into a prepared seedbed, as the Persian clover seed is so small. Deep sowing is the main factor reducing establishment and subsequent production.

When sowing, drop seed onto the soil surface and cover it by using light harrows or a piece of weldmesh. A level and even soil surface is important to ensure good seed placement. If irrigating, sow onto a prepared dry seedbed or cereal stubble, then water up. If watering up on crusting soil in February or March, a second irrigation should be applied 3 to 5 days after the first to prevent the formation of a surface crust. When sowing Persian clover with other species, ensure the seed is mixed properly, as the small seeds of Persian often settle out on the bottom of the seed box. Direct drilling can be a successful sowing method but Persian clover seedlings compete poorly with other species, so higher sowing rates are required. Seed placement and total control of both competing weeds and redlegged earth mite are crucial to successful establishment.

Grazing over summer to reduce herbage residues facilitates the breakdown of hard seed and improves seedling regeneration. This is essential in hard seeded varieties. Grazing in autumn is important to control weeds that can smother small Persian clover seedlings. To increase winter production, Persian clover can also be sown with oats or a tetraploid ryegrass, such as Tama or Tetila. Seed of the hard seeded varieties of Persian clover that has been harvested on-farm requires scarification before it is sown.

High density legume (HDL) break-crops

Persian is being increasingly grown in a mixture with other annual legumes such as berseem, arrowleaf and balansa clover as a one year special purpose forage legume break crop in crop rotations. These forage crops act as a disease break, increase soil nitrogen and offer the opportunity to control herbicide resistant weeds. They can be grazed, cut for silage or hay, green manured or a combination of the above. The sowing rate for Persian in these mixtures is typically about 3–5 kg/ha. Higher seeding rates promote early growth. The best forage legumes are later maturing varieties with high levels of disease resistance that maximise herbage production and nitrogen fixation. Commonly only three forage legume types are mixed together at a total sowing rate of 10–12 kg/ha.

Table 2. Pasture mixes and sowing rates (kg/ha)

Pasture type Dryland Irrigation Remarks
Persian alone 3–5 6–8 Grazing and hay or silage, N build up
Persian +
Sub. clover
Grazing, hay or silage,
N build-up
Persian +
Tetraploid ryegrass
Increased winter feed
Persian +
Earlier winter feed
High density legume forage break-crop
— Persian
— Berseem
— Arrowleaf
— Balansa
Winter-spring feed, grazing, hay/silage, green manure, disease break, N build-up


Inoculation with Group O strain of rhizobia is recommended.


Fertiliser rates ensuring 11–23 kg of phosphorus (e.g. 125–250 kg/ha single superphosphate) should be applied. However, these rates need to be adjusted depending on soil P levels as indicated by soil tests. Consult your agronomist for appropriate soil test levels for your situation.


Persian clover recovers well from grazing providing it is allowed to attain complete ground cover before being re-grazed. The stocking rate should be reduced during flowering to ensure sufficient seed is set for regeneration in the following year. A high proportion of mature seed consumed by stock passes through the rumen undigested and should germinate in the dung. Seedling regeneration in autumn is promoted by removing most of the dry plant residues over summer by grazing.


During the early growth stages, Persian clover is very sensitive to weed competition. If severe competition is expected, crop for one or two years to reduce weeds before sowing Persian clover. In paddocks irrigated in February, barnyard grass (Echinochloa sp.) is often a problem after sowing. Heavy stocking for a short period is the best means of controlling barnyard grass once Persian clover is firmly anchored. Grazing regenerating swards in autumn is important to prevent weeds smothering Persian clover seedlings. Winter broadleaf weeds can be controlled using herbicides but some plant damage is likely as Persian clover is sensitive to some commonly used broad-leaf weed control herbicides. Consult your local NSW Agriculture office for information on chemical weed control.


In thick irrigated swards during warm, humid spring weather, leaf rust (Uromyces trifolii-repentis) and clover rot (Sclerotinia trifoliorum) can present serious problems. Varieties differ greatly in their susceptibility to leaf rust (see Table 1) but grazing or mowing will reduce the rust inoculum and lower the humidity in the sward. Maral Persian clover is highly susceptible to leaf rust and should not be grown for two consecutive years in the same paddock. Persian clover is highly tolerant to clover scorch (Kabatiella caulivora) and resistant to sub. clover rootrot (Phytophthora clandestina).


Seedlings are very susceptible to attack by redlegged earth mite (RLEM) and lucerne flea, and chemical control is often required within one week of germination. Sitona weevil and heliothis can cause damage and regular crop inspections should be made and control measures carried out if warranted. Persian clover is rated as resistant to the spotted alfalfa aphid, extremely susceptible to the cowpea aphid and blue-green aphid, and tolerant of sitona weevil. Chemical control for RLEM should consider a new method aimed at more timely spraying. Contact your NSW Agriculture District Agronomist for further information.

Feed value

Persian clover is a very palatable and nutritious species. The Pastoral Research Institute at Hamilton, Victoria, has investigated the feed value of Maral Persian clover and results are summarised in Tables 3 and 4. Although Maral Persian has above average digestibility, other Persian clover varieties are thought to have digestibilities similar to other legumes such as sub. clover.

Sowing Persian clover in a mixture with tetraploid ryegrass or oats will reduce the risk of bloat. Other standard bloat control measures should also be considered when cattle are grazing pastures of Persian clover. Although some varieties claim not to cause bloat, care should be taken where Persian forms a large proportion of the feed base. Persian clover is non-oestrogenic and therefore will not cause infertility or reproductive disorders in ewes. There have been isolated reports of photosensitisation in sheep grazing Persian clover in the Murrumbidgee Irrigation Area and in north-eastern Victoria. The incidence of urinary calculi (clover stones) may increase in sheep and red gut may also occasionally occur in sheep grazing Persian clover.

High liveweight gains can be achieved as a result of low neutral detergent fibre content and high voluntary consumption (Tables 3 and 4).


Under irrigation, annual dry matter yields of up to 15.7 t/ha have been obtained. In trial comparisons with early/mid-season sub. clover, later maturing Persian clovers have shown marked superiority in late spring and early summer growth when the sub. clover has senesced.

Autumn and winter growth has been similar to sub. clover in well drained paddocks, provided grazing management has ensured adequate regeneration. In wet winters in waterlogged paddocks, observations suggest Persian clover significantly out-yields sub. clover and is also a better option in high pH soils.

Table 3. Feed value of various hays*

Hay type

Crude protein
(% DM)

Neutral detergent fibre
(% DM)

Dry matter digestibility in vitro (% DM)

Maral Persian 16–21 (19) 24–45 (35) 63–78 (72)
Lucerne 16–22 (20) 40–46 (43) 60–70 (64)
Red clover 14–18 (16) 38–42 (40) 67–68 (68)
Pasture 15–17 (11) 40–75 (60) 49–71 (60)
Oats 5–9 (17) 55–75 (65) 53–65 (60)

*The range of values is given with the average in brackets

Table 4. Weaner sheep fed various hays at the Pastoral Research Institute, Hamilton*

Hay type

Voluntary consumption
(kg DM/hd/day)

(% DM)

Fasted liveweight gain

Maral Persian clover
















* Reed, Flinn and Kelly (1986) Department of Natural Resources and Environment (Victoria). Agnote No. 3462/86.

Maral Persian clover has been compared with berseem clover (variety Bigbee) at Windsor and Taree in New South Wales and Numurkah in Victoria. Autumn-winter dry matter production was superior to berseem at Taree and Numurkah but inferior at Windsor.

Late maturing varieties sown in irrigation areas in late February can provide four grazings from late April to early September, a hay cut in mid-November, and either another grazing in mid-December or seed harvest in January.

Seed yields

Following grazing, Persian clover seed can be harvested for resowing. Average seed yields have been 150 to 300 kg/ha but potential seed yields of 1000 kg/ha have been measured. Seed is yellow to light brown in colour.

Paddocks should be locked up when the first flower appears to maximise seed set of regenerating pastures. Hard grazing just prior to flowering will greatly reduce seed yields. Early flowering cultivars require good soil moisture until late October for good seed set. In later flowering varieties, irrigation or abundant rainfall is required from mid-November to mid-December to prevent moisture stress during flowering. For later maturing varieties, the last irrigation should be carried out from mid to late December, allowing the crop to mature by mid-January. Seed crops need to be treated more leniently.

Any delay in harvest carries the risk of lodging, shattering and possible rain damage, resulting in shot and sprung seed. Windrowing or direct heading are both viable harvesting options. Open-front headers are preferred and crop lifters will be needed when direct heading in lodged crops. Drum speed should be high, concave closed and air draught three-quarters to fully open. On headers with a seconds box, seed is bagged off in the same way as seconds wheat. Before harvesting, seal any holes in the seconds box.

Many varieties are protected under the Plant Breeders Rights Act, and seed of these varieties cannot be produced for sale without the authorisation of the owner.

Special notes

Livestock health disorders

Pasture improvement may be associated with an increase in the incidence of certain livestock health disorders. Livestock and production losses from some disorders are possible. Management may need to be modified to minimise risk. Consult your veterinarian or adviser when planning pasture improvement.

With respect to Persian clover, livestock health disorders of particular note are:

  • enterotoxaemia (pulpy kidney)
  • photosensitisation sometimes
  • bloat in cattle
  • urinary calculi (clover stones) incidence may increase in sheep
  • red gut in sheep occasionally.

Native vegetation

The Native Vegetation Conservation Act 1997 may regulate some pasture improvement practices where existing pasture contains native species. For further details, inquire through your office of the Department of Infrastructure, Planning and Natural Resources.