Trifolium vesiculosum Savi

Symbol: 
TRVE
Group: 
Dicot
Family: 
Fabaceae
Description: 

Herbaceous, highly productive, cool-season winter annual clover suitable for hay, grazing, seed production, soil improvement, and wildlife forage. Well-adapted to overseeding of perennial warm-season grasses. Produces forage later in the spring than crimson and sub clover. Upright growth habit, to 40-50 inches (100-130 cm) under favorable conditions.

Uses: 
Pasture
Hay
Silage
Mixture
Monoculture
Soil Improvement (Green manure)
Soil Protection (Cover Crop)
Pollinators
Seed
Wildlife

Species Selection Characteristics

Annual Precipitation (inches): 
36 to 40
40 to 50
50 to 60
60 to 70
70 to 80
80 to 100
100 to 120
120 to 140
140 to 160
> 160
Plant Hardiness Zones (cold tolerance): 
7a
7b
8a
8b
9a
Heat Zone (July Mean Max Temperature): 
< 14 °F
14 to 18 °F
18 to 22 °F
22 to 26 °F
26 to 30 °F
30 to 34 °F
34 to 38 °F
38 to 42 °F
42 to 46 °F
46 to 50 °F
50 to 53 °F
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
84 to 88 °F
88 to 92 °F
92 to 96 °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
Soil Drainage Tolerance: 
poorly drained
somewhat poorly drained
moderately well drained
well drained
somewhat excessively drained
Flooding Tolerance: 
3-6 days
Soil Salinity Tolerance: 
Moderately sensitive, 1.5–3 dS/m

Identification Characteristics

Type: 
Legume
Growth Season: 
Cool
Identification Characteristics: 

Inflorescence: Large conical flower head up to 2 inches (5 cm) long has white to pink flowers opening from bottom to top, browning when mature.

Mostly upright stems grow to 3-4 feet (90-120 cm), are glabrous (not hairy), hollow, smooth, and often purple.

Palmately trifoliolate, arrow-shaped leaves have a characteristic large, white V mark.

Stipules are white, long, narrow, and pointed, with prominent veins.

Deep taproot can penetrate up to 4.5 feet (140 cm).

Seeds are about twice the size of white clover, with 400,000 per lb (880,000/kg). Nearly 70% are hardseeded, seed requires scarification for satisfactory germination.

Growth Habit and Stand Life

Mostly upright stems grow to 3-4 feet (90-120 cm). Annual.

Life Cycle: 
Winter annual

Climate and Soil Suitability Zones

Climate Tolerances: 

Grown throughout the mid-south and southeastern United States (USDA Plant Hardiness Zones 9a-8a). It requires 18-25 inches (450-650 mm) minimum precipitation or irrigation.

Soil Tolerances: 

Tolerates moderately acid to moderately alkaline soils (pH 5.6-8.4) that are well- to moderately well-drained. Not suited to sandy, droughty soils with low fertility. Will not survive poorly drained soils. Moderately sensitive to salinity (1.5-3 dS/m).

Quantitative Tolerances: 

Arrowleaf Clover Suitability Tolerance Values

Suitability Class

Jan Min (°C/°F)*

July Max

C/°F)

Annual Precip (mm/in)**

Soil pH***

Soil Drainage 

Soil Salinity (dS/m)#

Well-suited

-10/14

32/90

1524/60

5.8-7.5

MWD-WD

<2

Moderately suited

-12/10

34/93

1270/50

5.5-8.0

SPD-SED

2-3

Marginally suited

-15/5

36/97

1016/40

5.0-8.5

SPD-ED

3-4

*Cold temperature tolerance: USDA Plant Hardiness Zones - based on average annual extreme minimum temperature; 7a-9a as a winter annual.

Heat Zone - based on Mean Max July Temperature: 92-96 °F.

Latitude delimitations: 30-35 degrees N, 99 degrees West boundary.

**Precipitation minimum requirements important for fall, winter, spring seasons, since planted as a winter annual in the southeast. Zone: 36-40 inches and greater.

Rooting: tap, to 150 cm.

*** Soil pH tolerance: NRCS Range and Pasture Handbook, Chapter 3 classification for arrowleaf clover is moderately acid to moderately alkaline (5.6-8.4).

Soil drainage: NRCS Range and Pasture Handbook, Chapter 3 classification for Arrowleaf Clover is WD-PD. 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 Arrowleaf Clover for the classes 1-7: 5, 20, 55, 100, 100, 55, 20, respectively.

Flooding Tolerance: Brief (3-6 days). [Not listed in NRCS documents.]

# Soil salinity tolerance: NRCS Range and Pasture Handbook, Chapter 3 classification for clovers (alsike, Berseem, white, red, strawberry) is moderately sensitive (1.5-3 DS/m). Arrowleaf is not listed.

Suitability Maps

Historically, maps have been drawn based on primary use areas, showing broad geographic areas, e.g. Compendium of Common Forages maps within Forages: An Introduction to Grassland Agriculture, 7th ed. (2018), John Wiley & Sons, Inc.

 

More highly detailed maps, based on quantitative climatic and soil factor tolerances and using GIS spatial grids, provide information on where species are suitable for a variety of intended uses.

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database. The procedure used to produce these suitability maps is described below.

Suitability curves were developed for each clover species for three climate variables (average annual precipitation, average July maximum temperature, and average annual extreme low temperature) and three soil variables (drainage class, pH, and salinity). For each variable and each species, the curves were fit using estimated yield data across the full range of values for the given variable.  

The coefficients for the model equations were applied to spatial data layers representing each climate and soil variable, resulting in spatial outputs of percent yield for each of the clover species and each climate and soil variable. The percent yield layers were then classified into four suitability classes, as follows: 

100%-75% - Suitable
75%-50%  - Moderately suitable
50%-25%  - Marginally suitable
25-0%    - Not suitable

Finally, three "hybrid" suitability layers were produced for each clover species based on combinations of 1) the three climate variables, 2) the three soil variables, and 3) all six climate and soil variables together.  These combined suitability layers were created by selecting for each location the lowest suitability value of the included variables, with the idea that the overall suitability for a species will be limited by the most restrictive factor. 

Data sources
----------------
Climate data: 800m PRISM 30-year normals for years 1981-2010 (PRISM Climate Group, Oregon State University, http://prism.oregonstate.edu, accessed 2018-01-17)

Soils data:  NRCS STATSGO (Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. U.S. General Soil Map (STATSGO2). Available online at https://sdmdataaccess.sc.egov.usda.gov. Accessed 2018-01-10.

 

QUANTITATIVE TOLERANCES GIS-BASED MAPS

The contiguous USA

Climate Factors

Soil Factors

Combined Factors

Minimum Temperature

pH

All climate and soil factors (most limiting)

Maximum Temperature

Drainage

All soil factors (most limiting)

Precipitation

Salinity

All climate factors (Most limiting)

Click on the thumbnail image to view a larger map.

 
State Maps
Alaska
Climate Factors Soil Factors Combined Factors

Minimum Temperature

pH

Climate and Soil

Maximum Temperature

Drainage

All Climate

Precipitation

Salinity

All Soil


Hawaii
Climate Factors Soil Factors Combined Factors

Minimum Temperature

pH

Climate and Soil

Maximum Temperature

Drainage

All Climate

Precipitation

Salinity

All Soil

Oregon
Climate Factors Soil Factors Combined Factors

Minimum Temperature

pH

Climate and Soil

Maximum Temperature

Drainage

All Climate

Precipitation

Salinity

All Soil

 

Yield Potential and Production Profile

Planted during the autumn in the southeastern USA with annual ryegrass or other annual grass or interseeded into warm season grass pastures where winter and spring temperatures are sufficiently warm to allow growth during this period. Arrowleaf is later maturing than crimson clover, and continues to grow into early July.

Cultivars

Select a cultivar that has been shown in local university trials to have improved resistance to virus complex, crown rot, and alfalfa weevils and aphids. ‘Blackhawk’ was released by Texas A&M in 2013. It matures earlier than ‘Apache’ (medium) and ‘Yuchi’ (late) cultivars. ‘Arrotas’ is a late-maturing, high yielding cultivar released by the Tasmania Institute of Agriculture.

Management Level Required

Suitable Management Level: 
High
Medium

Quality and Antiquality Factors

Quality Factors: 

High quality forage; improves pasture quality when overseeded into warm-season (C4) grasses.

Anti-quality Factors: 

Minimal bloat risk.

Image Gallery

Resources

Publications: 

Books and Book Chapters

  • Forages: An Introduction to Grassland Agriculture (7th Edition, 2018)
    • Sheaffer, Craig C., M. Scott Wells, and Jerry Nelson. 2018. Legumes for Northern Areas. Chapter 8 In: Forages: An Introduction to Grassland Agriculture. Seventh Edition. John Wiley & Sons, Inc.
  • Clover Science &Technology (Agronomy Monograph No. 25, 1985)

Extension Fact Sheets and Circulars

USDA NRCS Fact Sheet and Plant Profile 

Organizations

Vendors