Trifolium resupinatum L.

Persian Clover field flowering - Hollena Nori
Symbol: 
TRRE4
Group: 
Dicot
Family: 
Fabaceae
Uses: 
Pasture
Hay
Silage
Mixture
Monoculture
Soil Improvement (Green manure)
Soil Protection (Cover Crop)
Pollinators
Description: 

Persian clover (Trifolium resupinatum L.) is an annual, herbaceous legume with prostrate or semi-erect growth habit to 4 feet (1.2 m). It forms dense swards and has a rosette growth habit under grazing.

It is mostly used for pasture and hay, producing highly palatable and nutritious forage. Its high protein and moisture content make it difficult to ensile. Soft-seeded cultivars are used for hay and silage, while hard-seeded varieties are used on dryland pastures. Soft-seeded cultivars are not well suited for dryland pastures, as the seeds germinate quickly during summer and young plants often die during dry periods. 

It has high forage yield and excellent regrowth following grazing or cutting.

Identification Characteristics

Type: 
Legume
Growth Season: 
Cool
Identification Characteristics: 

Inflorescence is a flattened head with highly fragrant, pink to purple flower petals having a resupinate (inverted or upside down) corolla, hence the name resupinatum. Single-seeded pods split open at maturity. Seeds are tan to reddish-brown and very small (364,000-900,000/lb; 800,000–2,000,000/kg). Stems are hollow, branching from the base. Leaves are trifoliolate with 0.4 to 1.2 inch (1-3 cm) long oval to oblong serrated leaflets. Stipules pointed with red veination. Roots: tap rooted.        

Growth Habit and Stand Life

Prostrate or semi-erect growth habit to 2 feet (60 cm). Forms dense swards and has a rosette growth habit under grazing.

Life Cycle: 
Winter annual

Yield Potential and Production Profile

In moderately cold areas, it can be sown in autumn to be used during spring. In extremely cold areas it is often sown in the late spring in combination with wheat, so that it is available for grazing or hay once the cereal crop has been harvested. In warmer regions, Persian clover is fall-sown, harvested in early spring and followed by a cereal grain crop.

Persian clover can be cut 2 or 3 times, but not closer than 4 inches (10 cm) to allow for vigorous regrowth. In irrigated fields the optimum cutting interval is approximately 6-9 weeks in the growing season, allowing dry matter yields of 5-6.5 tons/ac (12-15 t/ha). Planting rate is 6 to 8 lb/acre (5-10 kg/ha).

Cultivars

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 (1-2%). Flowering and maturity is mostly late. The cultivars Maral, Morbulk, Laser, and Lightning belong to this subspecies. They are typically planted alone or in combination with oats or annual ryegrass in regions with >600 mm per year or in irrigated systems.

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. Subspecies resupinatum is sown in dryland systems in regions with >450 mm per year as a winter forage crop in warmer areas or as a summer annual in more northern or higher elevation areas.

Climate and Soil Suitability Zones

Climate Tolerances: 

Originating in central Asia and the Mediterranean area, Persian clover is traditionally cultivated in cold areas in the Middle-East and central Asia (Iran, Afghanistan, and northern Pakistan). In the USA, Australia, and France, it is a minor fodder crop which is well suited to areas with a summer dry, Mediterranean type climate. 

Suited to USDA Plant Hardiness Zones 7b-9b. It can survive cold winter temperatures (to 10°F, -12 °C) and frost, but develops slowly at low temperatures. Moderate heat tolerance, suited to July mean maximum temperatures of 79-82 °F (26-28 °C). Requires at least 18 inches (450 mm) of annual precipitation.

Soil Tolerances: 

Suited to sandy to loam to clay-loam soils with a pH between 5.5 and 9, with optimum growth in neutral to slightly alkaline soils (pH 7-8). It tolerates waterlogging, mild salinity (3-5 dS/m).

Quantitative Tolerances: 

 

Suitability Class

Jan Min (°C)*

July Max

C)

Annual Precip (mm)**

Soil pH***

Soil Drainage 

Soil Salinity (dS/m)#

Well-suited

-10

26

650

6.5-7.5

MWD-WD

1-2

Moderately suited

-12

27

550

6.0-8.0

SPD-SED

2-3

Marginally suited

-14

28

450

5.5-9.0

PD-SED

3-4

*Low temperature: USDA Plant Hardiness Zones: 7b-9b

   Rooting: taproot to 3 feet (90 cm).

*** Soil pH: Strongly Acid to Moderately Alkaline: 5.5-9.0. 

† Soil drainage: Tolerates water-logged soils. Soil drainage class abbreviations: 1=VPD, very poorly drained; 2=PD, poorly drained; 3=SPD, somewhat poorly drained; 4=MWD, moderately well drained, 5=WD, well drained; 6=SED, somewhat excessively drained; 7=ED, excessively drained. Percent relative yield for balansa clover for the classes 1-7: 15, 40, 75, 100, 100, 55, 20, respectively.

# Soil salinity: Mildly saline soils (3-5 dS/m)

 

Suitability Maps

 

 

Quality and Antiquality Factors

Quality Factors: 

Forage is palatable with high digestibility and crude protein (16-28%).

Anti-quality Factors: 

It can produce bloat in cattle and photosensitization may occur on pure stands grazed by sheep.

Species Selection Characteristics

Annual Precipitation (inches): 
16 to 20
20 to 24
24 to 28
28 to 32
32 to 36
36 to 40
Plant Hardiness Zones (cold tolerance): 
7b
8a
8b
9a
9b
Heat Zone (July Mean Max Temperature): 
53 to 56 °F
56 to 59 °F
59 to 62 °F
62 to 65 °F
65 to 68 °F
68 to 71 °F
71 to 74 °F
74 to 77 °F
77 to 80 °F
80 to 84 °F
Soil pH Tolerance: 
Moderately acid, 5.6–7.3
Moderately acid to moderately alkaline, 5.6–8.4
Slightly acid to moderately alkaline, 6.1–8.4
Near neutral, 6.1–7.3
Alkaline, 6.7–9.0
Soil Drainage Tolerance: 
poorly drained
somewhat poorly drained
moderately well drained
well drained
Flooding Tolerance: 
7-30 days
Soil Salinity Tolerance: 
Moderately tolerant, 3–6 dS/m

Management Level Required

Suitable Management Level: 
High
Medium

Image Gallery

Resources

Publications: 

Department of Primmary Industries, New South Wales. 2018. Persian Clover. https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/species-varieties/pf/factsheets/persian-clover

Heuzé V., Tran G., Giger-Reverdin S., Lebas F. 2015. Persian clover (Trifolium resupinatum). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://feedipedia.org/node/244      Last updated on September 30, 2015.

McCaskill M., Borg, D. 2006. Managing pastures in saline areas. http://www.ccmaknowledgebase.vic.gov.au/kb_resource_details.php?resource_id=1703

Moot, Derick and Dick Lucas. 2012. Legumes for Hill Country. http://www.lincoln.ac.nz/PageFiles/23598/2012-04-03-Castlepoint-Field-Day-handout.pdf

New England Wild Flower Society - Go Botany. https://gobotany.newenglandwild.org/species/trifolium/resupinatum/

Onal O., Kask Y., Nalbanto F., Deveci M., Acar Z. 2016. The nutritive value of Persian clover (Trifolium resupinatum) herbage grown under irrigation in northern Victoria.  Options Mediterranéenes 14: 201-204. http://om.ciheam.org/om/pdf/a114/a114.pdf