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Common Names

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alfalfa
lucerne
luzerne
snailclover
purple medick
yellow alfalfa
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Cover Value

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More info for the terms: cover, density, marsh

Dabbling ducks (mallards, gadwalls, blue-winged teals, northern pintail,
northern shovelers, American green-winged teals, and American wigeons)
will use haylands for nesting, although this is not the most preferred
nesting cover. Over 80 percent of nests found in haylands are found in
alfalfa, which is highly attractive to mallards and gadwalls after it
has reached half of its mature height and density [16,64,73].

Sharp-tailed grouse and prairie chickens prefer early seral vegetation,
such as retired crop and haylands that contain alfalfa, for courtship
grounds [63,83]. Areas in the cropland adjustment program (CAP), in
which seeded grasses and legumes (particularly alfalfa) are left for
wildlife habitat, are used for food and cover by a variety of birds,
including pheasant, sharp-tailed grouse, greater prairie chicken,
American bitterns, marsh hawks, short-eared owls, and many passerine
birds [30].

Regional cover values of alfalfa for selected wildlife species are as
follows [27]:

UT CO WY MT ND
Elk ---- poor ---- poor ----
Mule deer poor ---- poor ---- good
White-tailed deer ---- poor good good ----
Antelope poor fair poor good good
Upland game birds good good good good good
Waterfowl fair ---- good ---- good
Small nongame birds good good good good good
Small mammals good good good good good
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Description

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More info for the terms: association, herb

Alfalfa is an introduced perennial herb. It can reach 24 to 35 inches
(60-90 cm) in height, with 5 to 25 or more erect stems per plant, which
arise from a narrow, woody crown. It has a deep taproot, 10 to 17 feet
(3-5 m) in sandy soils, and 23 to 30 feet (7-9 m) under favorable
conditions [50,110]. Many older plants have roots up to 63 feet (19 m)
deep. A record depth of 130 feet (39 m) was reported in the roof of a
mine tunnel in Nevada [39]. Varieties are available with different root
system types: taproot, branching roots, rhizomatous, and creeping
(horizontal rootstocks that give rise to independent plants) [94,110].
The roots form nodules in association with Rhizobium spp. bacteria,
which fix atmospheric nitrogen. Alfalfa also has endomycorrhizal
associates [27].

Saponic glycosides are found in alfalfa, which are suspected of
contributing to bloat in ruminants [29].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Distribution

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Alfalfa originated in southwestern Asia, was first cultivated in Iran,
and now has a worldwide distribution due to its popularity as an
agricultural species. It was introduced into the United States in 1736
in Georgia, but it was not until around 1850 that it began to be more
widely planted. It is planted in all 50 states and is widely planted in
Canada. It is naturalized in many areas [12,37,50,95].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Fire Ecology

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More info for the terms: fire regime, root crown

As a perennial with a narrow root crown, alfalfa will survive most fires
by sprouting after being top-killed. Alfalfa hard seeds may be
scarified by moderate-severity fires [126,91].

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Fire Management Considerations

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More info for the terms: fire management, forb, fuel

The fire susceptibility of rangeland vegetation depends on the reduction
of fuel loads through animal use or drought which reduces standing crop
size [49].

Seeded alfalfa fields are often burned prior to growth initiation in the
spring to reduce insect pests. This treatment results in destruction of
insect eggs and adults, and reduces debris from the previous growing
season that encourages insect population growth. Since soil preburn
conditions are attained within 160 days of the fire, it is unlikely
that a 3-year interval between fires would be detrimental to the soil
[28].

Under current evaluation is a method of presuppression fire management
called "greenstrip management." This involves the production of a
vegetative fuelbreak of green plants that are less flammable than the
surrounding native vegetation. Alfalfa is the most commonly used forb
for this purpose [86].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Growth Form (according to Raunkiær Life-form classification)

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More info on this topic.

More info for the terms: geophyte, hemicryptophyte

Hemicryptophyte
Geophyte
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Habitat characteristics

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Alfalfa is well adapted to a wide range of climatic and edaphic
conditions, but it does best in deep, loamy soils with porous subsoils.
It is intolerant of flooding, waterlogging, or poor soil drainage. It
requires large amounts of lime. Alfalfa does not do well on acid or
very alkaline soils, although it will tolerate some alkalinity. It has
fair salt tolerance [47,50,110]. It is naturalized to roadsides, old
fields, and waste places [37].

Alfalfa will tolerate drought and is known as a good producer in dry
years. It needs about 12 inches (30 cm) of precipitation per year on
good soils, 14 inches (36 cm) on less favorable soils [111]. Irrigation
greatly enhances productivity in dry climates [50,106].

Regional elevation distributions are as follows:

Utah 4,500 - 8,600 ft (1,364-2,606 m)
Colorado 4,800 - 8,500 ft (1,455-2,576 m)
Wyoming 3,700 - 8,800 ft (1,121-2,667 m)
Montana 3,400 - 6,600 ft (1,030-2,000 m) [27]
Idaho up to 8,000 ft (up to 2,424 m) [110]

Alfalfa does poorly at high elevations [53,109].
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bibliographic citation
Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Habitat: Cover Types

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the term: cover

Occurs in most SAF Cover Types
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Habitat: Ecosystem

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

More info for the term: shrub

FRES10 White - red - jack pine
FRES11 Spruce - fir
FRES12 Longleaf - slash pine
FRES13 Loblolly - shortleaf pine
FRES14 Oak - pine
FRES15 Oak - hickory
FRES16 Oak - gum - cypress
FRES17 Elm - ash - cottonwood
FRES18 Maple - beech - birch
FRES19 Aspen - birch
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES22 Western white pine
FRES23 Fir - spruce
FRES24 Hemlock - Sitka spruce
FRES25 Larch
FRES26 Lodgepole pine
FRES27 Redwood
FRES28 Western hardwoods
FRES29 Sagebrush
FRES30 Desert shrub
FRES31 Shinnery
FRES32 Texas savanna
FRES33 Southwestern shrubsteppe
FRES34 Chaparral - mountain shrub
FRES35 Pinyon - juniper
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES39 Prairie
FRES40 Desert grasslands
FRES41 Wet grasslands
FRES42 Annual grasslands
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Habitat: Plant Associations

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More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

Occurs in most Kuchler Plant Associations
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Habitat: Rangeland Cover Types

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More info on this topic.

This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the term: cover

Occurs in most SRM Cover Types
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Immediate Effect of Fire

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More info for the terms: root crown, top-kill

Moderately severe fires will top-kill alfalfa shoots, and severe fires
may cause damage to or kill the root crown, killing the plant [85].
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bibliographic citation
Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Importance to Livestock and Wildlife

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More info for the terms: cover, formation, frequency

Alfalfa is consumed by most herbivores and omnivores, including all
classes of livestock and big game animals. It is valued for
rehabilitation of overgrazed ranges in part because it begins growth
early and retains green succulence later than grasses [111]. Graham
[45] reported that 27 species of birds and 46 species of mammals are
known to use alfalfa. Birds utilizing the leaves, flowers, or seeds
include sage grouse, sharptailed grouse, pheasant, California quail,
gray partridge, American wigeon, mallard, and little brown crane
[88,104,111]. Alfalfa is consumed by juvenile prairie chickens in
summer, composing up to 7 percent of crop volume [101].

The seeds are consumed by rodents, rabbits, upland birds, waterfowl, and
songbirds. They are a preferred food for deer mice in Nevada [35].
Alfalfa is a source of nectar and pollen for insects [111,114]. Many
small mammals, including jackrabbits, marmots, pocket gophers, prairie
dogs, various ground squirrels, kangaroo rats, and mice graze alfalfa.
Pocket gophers consume roots [45,111].

Stands containing alfalfa are a preferred location for brood rearing by
Canada geese. They nest elsewhere, then bring the brood to these sites,
apparently for both food and cover [48]. The gray partridge is often
found nesting in agricultural lands containing alfalfa [11].

Alfalfa is rated as highly valuable for elk in summer and fall, but it
is not used as food in winter and spring [1,6,67,111]. Alfalfa use by
mule deer and white-tailed deer is highest in summer and fall
[1,6,26,108,111]. Mule deer in the Great Basin sagebrush formation in
California will use small amounts of alfalfa through the winter [68].
Alfalfa is a highly preferred species for pronghorn in the summer. Does
and fawns were found at greater frequency on sites planted with alfalfa
mixtures than on adjacent shrub-dominated rangeland [111,127]. Moose
will consume alfalfa in summer, and bighorn sheep consume alfalfa in
winter and spring [6,92].
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bibliographic citation
Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Life Form

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More info for the term: forb

Forb
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Management considerations

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More info for the terms: competition, cool-season, cover, forbs, forest, grassland, litter, natural, prescribed fire, presence, seed, selection, shrub, shrubs, warm-season, wildfire

Alfalfa is the most highly valued and widely planted legume. Before
planting, however, managers should take into account the grazing
management plan for the range unit. Seeded species can do more
harm than good, and alfalfa may not always be the most appropriate
legume [46,97]. There is a general trend for preferring native species
for rangeland over introduced species where feasible. It is often the
case that assembly of native seed mixtures is more expensive than
commercially available seed. There are, however, some companies that
are starting to make native legumes available [96,97].

The choice of alfalfa for plantings should depend on climatic and
edaphic conditions favorable to alfalfa establishment. A minimum of 10
to 12 inches (28-38 cm) of precipitation is needed, at least half of it
not snow. Alfalfa is the only exotic legume recommended for planting in
southwestern Saskatchewan and southeastern Alberta [56]. It appears to
be limited by high elevations [109]. Alfalfa performance and
persistence is quite variable and is dependent on a number of factors,
not all of them predictable [42]. Seedings of alfalfa mixtures in
southeastern Oregon have persisted for 17 years or more, and as long or
longer in other western states [60,99]. The weather factors following
seeding are considered to be highly important in determining successful
establishment. A severe frost following germination is lethal [50].

Grazing management is also influential in establishment and persistence.
'Nomad' alfalfa normally forms seed, so grazing prescriptions that are
designed to favor trampling of seed (thus scarifying it and making a
firm seedbed) may improve persistence [60]. A general trend in western
rangeland seedings is that initial establishment and productivity are
usually good to excellent and drop off as the stand matures [95]. In
southern Oregon, a 1972 aerial seeding of 'Nomad' alfalfa in stands of
crested wheatgrass was "spotty" by 1975 and still lower by 1986. In a
pinyon-juniper type in central Utah, initial coverage of alfalfa on a
chained and seeded rangeland was excellent but declined slightly from
1982 to 1985 [21]. Creeping rooted cultivars are longer lived than
other strains on sites with 12.6 to 15 inches (32-38 cm) precipitation
[51]. The value of alfalfa is such that even a small amount contributes
to forage quality and productivity [49].

Since it is difficult to choose seed mixtures that are perfectly adapted
to particular conditions and produce a specified composition of species,
mixtures of a wide variety of seeds are preferred in most cases [21].
The choice of the grass species to be seeded with alfalfa has an effect
on alfalfa persistence. 'Whitmar' bluebunch wheatgrass
(Pseudoroegenaria spicata) allowed more alfalfa to coexist than did
'Greenar' bluebunch wheatgrass or 'Nordan' crested wheatgrass (Agropyron
cristatum) [60].

In the western juniper (Juniperus occidentalis) zone of central Oregon,
a range planting study failed to establish alfalfa. The area receives
11 to 15 inches (28-38 cm) precipitation and has shallow clayey loam
soil. The author concluded that the inclusion of seeds of grasses,
forbs, and shrubs other than crested wheatgrass and Siberian wheatgrass
(Agropyron sibiricum) is "questionable" for the western juniper zone
[69]. It is probable that the planting conditions may have been too dry
for good establishment or that deer or rodents may have damaged the seed
and/or seedlings too heavily. There are other reports of range seeding
failures and plantings that did not have productivity results as high as
expected; these also may have failed to take into account initial
planting conditions or may have failed for more obscure reasons
(competition, rodent predation on seeds or roots etc.) [14,23,60,102].

For rangeland improvement in aspen (Populus spp.) parklands in
Saskatchewan, smooth brome (Bromus inermis) is planted with alfalfa.
Areas that have been chained and seeded are susceptible to regrowth of
aspen and prickly rose (Rosa acicularis) suckers. Application of
herbicides to control aspen and prickly rose have a detrimental effect
on alfalfa. Alfalfa is sensitive to picloram, 2,4,-D and 2,4,5-T, and
is killed at levels applied to control woody species [7]. It may
therefore be only beneficial to include alfalfa in such plantings when a
mix of 2,4-D and picloram is applied 5 to 10 years after the forage
stand is seeded [8]. In a study to control woody reinvaders (aspen and
snowberry [Symphoricarpos occidentalis]) in burned and seeded aspen
parkland, it was found that early season, short-duration heavy grazing
severely reduced competition from woody suckers. Newly germinated
forage seedlings survived better and resulted in a more rapid
establishment of forages than under either late-season, short-duration
heavy grazing or no grazing [4].

Establishment: Alfalfa establishes best with a firm seedbed, and
drilling is the preferred method of seeding in most areas
[42,53,91,110]. Recommended planting depth is 1/4 to 1/2 inch (1 mm-
2 mm) [53]. Seed germination is inhibited by the presence of pine and
juniper litter over buried seed. In pinyon-juniper types, germination
may be enhanced by broadcast seeding rather than drilling [34,89]. No
added nitrogen is needed if the seed is inoculated with Rhizobium
bacteria. However, phosphorus, potassium, and sulfur should be
supplemented if the soil is deficient in these nutrients [110,114]. The
acid intolerance of alfalfa may be overcome by the addition of calcium
and nitrogen fertilizers, which counteracted the effects of low pH under
laboratory conditions [115].

Some recommended seeding rates (certified pure live seed) are as
follows:

For pure stands 15 - 20 lbs per acre (17-22 kg/ha) [50]
9 lbs per acre (10 kg/ha) [110]
10-15 lbs per acre(12.5-22 kg/ha) [53]

For mixed stands 1-2 lbs per acre (1.25-2.5 kg/ha) [53,111]
2.5 lbs per acre (2.8 kg/ha) [99]

Viable seed is bright olive green [111].

No significant effect on yield was detected between applications where
all seeds were mixed and seeded, and applications where alfalfa was
seeded alternately with crested wheatgrass [101].

The preference of deer mice for alfalfa seed has contribute seeding
failures in Nevada; deer and rodents probably contributed to seeding
failures in northeastern Washington and on a subalpine grassland study
in north-central Washington [32,35,109]. In a study of the combined and
individual effects of deer, rabbit, and rodent use of alfalfa, deer use
was found to have a greater negative impact than rabbit use. Rabbit
damage is usually minimal, except in peak rabbit population years [95].
The soil-loosening effect of alfalfa roots may increase rodent burrowing
activity, which can contribute to postestablishment failures [45].

Seeding dates vary with location. In South Dakota, late summer seedings
are more successful than spring seedings. Sowing can take place later
farther south; near the Gulf of Mexico, alfalfa can be sown as late as
October, and in the Southwest, plantings can be made as late as
December. North and east of Nebraska, spring sowing is usually best
with a companion grain crop [50]. If the management goal is to provide
a seasonally balanced grassland, it is important to delay seeding to
favor warm-season species. If planted too early, the tendency is to
establish a stand dominated by cool-season species [84].

Planting methods and further management considerations are detailed in
Horton 1989 [53], Hull and others 1958 [55], Love and Jones 1952 [73],
and in:

1. U.S. Department of Agriculture, Forest Service, Intermountain Forest and
Range Experiment Station. 1979. User guide to vegetation. Gen. Tech.
Rep. INT-64. Ogden, UT.
2. U.S. Department of Agriculture, Forest Service, Intermountain Forest and
Range Experiment Station. 1979. User guide to soils. Gen. Tech. Rep.
INT-68. Ogden, UT.

For postfire regeneration projects in Alberta, where much of the organic
matter is destroyed by fire, alfalfa seeded with wheatgrasses, red
fescue, brome grasses, and clovers is more successful in spring
plantings than fall plantings [2]. The concern has been raised that
seeding introduced species such as alfalfa can suppress native
vegetation. In degraded big sagebrush (Artemisia tridentata) habitat
types, cheatgrass (Bromus tectorum) is an invading species that is
reduced by moderate to severe wildfires. Since the native perennial
grass seed bank in these areas is depauperate, postfire seeding of
introduced species after such wildfires can greatly reduce the acreage
invaded by cheatgrass. These seedings appear to prevent revegetation by
species native to the area, so managers must be able to judge which
areas are likely to be invaded by cheatgrass after fire (which can be
partially predicted by the amount of unburned organic litter remaining
after a fire) and seed those, leaving other areas to natural
regeneration [128].

Livestock use: Rangeland use of alfalfa carries the risk of bloat in
cattle, horses, and sheep. This risk can be reduced by planting
perennial grasses to cover at least half of the site [50,110,114].
Bloat risk is also reduced by delaying grazing until after flowering is
completed [110].

Alfalfa does not persist on moderately to heavily grazed rangelands
unless there are well-timed rest periods [53]. A short period of
intense grazing during May and June is considered more favorable
management for alfalfa than a long period of summer grazing [97].
Alfalfa tolerates rotational grazing; stands will weaken rapidly if
grazed continuously [50]. Hafenrichter [46] recommends a rotation
deferred system in bunchgrass areas. Grazing should not be closer than
4 to 6 inches (10-15 cm). Alfalfa is sensitive to depletion of root
reserves in the fall and should not be grazed heavily at this time
[110]. Frequent, intense clipping decreases lateral shoot spread [95].
The longevity of alfalfa in some semiarid environments appears related
to the degree of utilization--persistence is enhanced when only lightly
used [99]. Some cultivars are more tolerant of grazing than others. A
prostrate growth form is associated with persistence under grazing [20].
For example, under close grazing, 'Nomad' alfalfa assumes a prostrate
form, which increases its tolerance to grazing [60].

Methods for hay production are detailed in [46,50,70,110,130,131].

Insect pests: The pea aphid (Acyrthosiphon pisum) causes stunted,
wilted plants and reduces cold hardiness. The alfalfa weevil (Hypera
postica) is the most important pest in the United States and Ontario.
It can defoliate both first and second cuttings of hay, reducing hay
yield up to 50 percent and also reducing hay quality. Alfalfa curculio
(Sitona scissifrons), a weevil that attacks leaf edges, is not a problem
in established stands but can destroy seedling fields. Lygus plant bugs
(Lygus spp.) mostly damage seed production. The alfalfa looper
(Autographa californica) is not a serious problem except where local
outbreaks can cause severe damage. Grasshoppers (Melanoplus spp.,
Camnula spp.) consume all plant parts and can be extremely destructive
in dry years [110].

Control of insect pests: The pea aphid, alfalfa weevil, and alfalfa
looper are subject to biological control; chemical control is also
recommended for the pea aphid, alfalfa weevil, alfalfa curculio, lygus
plant bugs on seed crops; outbreaks of alfalfa looper; and for
grasshoppers [110].

Diseases: Most diseases of alfalfa become more severe with the age of
the stand; most stands are free of disease the first year, with the
exception of alfalfa sickness. Disease can be established by the second
year, and by the fourth year, it is often uneconomical to maintain the
stand. Stands can be kept healthy by such management practices as
adequate fertilizer and water. Varieties should be chosen that are
resistent to diseases common to the area.

Leaf and stem diseases include common leaf spot, yellow leaf blotch,
black stem, downy mildew, and verticillium wilt. Crown and root
diseases include winter crown rot crown bud rot, bacterial wilt, alfalfa
sickness, and brown root rot [110].

Control: Burning in the spring before growth begins prevents crop
injury by the burn and reduces the amount of infected leaves. Crown and
root diseases are mitigated with adequate fertilizer and by allowing
plants to recover in the spring before cutting or grazing. Adequate
late summer growth builds up winter reserves and reduces disease
susceptibility [110].

Wildlife use: Sharp-tailed and sage grouse habitat can be developed in
North Dakota by planting brome grass and alfalfa and left undisturbed
until stand vigor declines. Vigor can then be restored by mechanical
disturbance, reseeding, or burning, with prescribed burning considered
the least disruptive to grouse [62,63]. For wildlife habitat
(particularly dabbling ducks) in the northern prairie pothole region, it
is recommended that native grasses be planted on sites that receive 20
inches (51 cm) or more annual precipitation, and that introduced grasses
and legumes (particularly alfalfa) be used in the drier areas. It is
considered better for duck nesting if fields of 40 acres (25 ha) or more
are established near or adjacent to wetland types of habitat [30].
Removal of cover by mowing affects the distribution of breeding ducks
but probably does not decrease the overall breeding population.
However, residual growth is an important component of selection of nest
sites for many species of ducks, and therefore nesting would be
increased by allowing some areas to go unmowed in the latter part of the
season [75].

Gray partridge nesting in North Dakota can be encouraged in alfalfa
stands that are adjacent to cereal crops (especially on roadsides and
field edges). These stands are best if left unmowed so that heights of
9 to 12 inches (23-30 cm) are achieved. Programs to leave unmowed
strips along the crop side of fields and roadsides could greatly
increase potential nest sites for gray partridge [11].

Upland sandpipers in North Dakota have experienced population declines,
largely due to past hunting and loss of habitat. Many acres of suitable
habitat have been converted to grasses and legumes, notably alfalfa and
sweetclover. Alfalfa fields are usually too tall for upland sandpipers,
which prefer cover heights between 6 and 12 inches (15 and 30 cm).
Alfalfa is not recommended for upland sandpiper habitat and therefore a
management goal to increase habitat for upland sandpipers would include
conversion of alfalfa fields to native vegetation where appropriate
[62].

Management for pronghorn includes the maintenance of rangeland in seral
stages such that grasses and forbs dominate, with a low (15-20 percent)
shrub cover [127]. This was accomplished historically by periodic
wildfire, and today can be accomplished by prescribed fire or by
chaining and drill-seeding big sagebrush communities dominated by tall
shrubs. Recommended seed mixtures contain approximately six species
each of grasses, forbs, and shrubs [127]. Including alfalfa in the seed
mixtures is highly recommended for a number of habitat types. This
technique is considered very successful for pronghorn habitat
improvement in southeastern Oregon [59,61]. After at least 6 years,
alfalfa constituted 10 percent of the vegetation on most planted sites
[127].

Cultivars: For nonirrigated land, 'Ranger' alfalfa is a hardy,
wilt-resistant variety. It is widely adapted throughout the northern
and central United States. 'Ladak' alfalfa produces a large first crop
but is very slow to recover recovery after cutting. It has some
resistance to wilt and leaf diseases. It is most valued in cold, dry
climates. 'Vernal' alfalfa is a variety developed in Wisconsin and has
excelled 'Ranger' in both yield and stand persistence. 'Nomad' alfalfa
is a creeping or pasture-type which persists under intensive and
continuous grazing. It has rather wide adaptation throughout the
Northwest and elsewhere under dry and cold conditions. 'Rambler'
alfalfa is also a creeping variety that spreads by true underground
roots. It is adapted to the prairie provinces of Canada and northern
areas in the United States [111,122].

A more complete list of cultivars and their availability can be found
in :

1. U.S. Department of Agriculture, Agricultural Research Service. 1960.
Alfalfa varieties in the United States. Agric. Handb. 177.
Washington, D.C.: U.S. Government Printing Office. 30 p.
2. Barnes, D. K.; Smith, D. L. 1984 Review and description of alfalfa
varieties. In: Report of the Alfalfa Improvement Conference.
Washington, DC: U.S. Department of Agriculture, Agricultural Research
Service: 115-118.
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Nutritional Value

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More info for the terms: density, fresh, selection

Alfalfa is considered one of the most nutritious forages available,
producing more protein per hectare than any other crop. It is
considered an important source of vitamin A, and of 10 other vitamins as
well [12,23,50,60]. White and Wight [122] found that pasture yield had
an inverse relationship to forage quality: the higher the density, the
lower the crude protein (CP) and dry matter digestibility. Phenological
stage accounts for 97 percent of the variation in neutral detergent
fiber and in vitro dry matter digestibility: nutritive value decreased
with maturity [103]. There have been numerous studies on the nutritive
value of fresh alfalfa, as hay, pelleted, and ensiled.

A selection of values for some characteristics is as follows [9,38,110]:

CP(%) available P(%) dry matter acid detergent
STAGE CP(%) digestibility(%) fiber(%)
_____________________________________________________________________
vegetative 32.8 31.8 0.44 84 18.1
flower 29.2 28 0.38 79 21.7
mature 25.6 24.2 0.32 74 25.3
regrowth 22.0 20.2 0.26 69 28.9 [38]

Digestible protein (%) for selected species is as follows [82]:

dried vegetative early bloom
________________________________________
Cattle 12 15.1
Sheep 12 15.3
Goats 12.4 14.6
Horses 11.9 14
Rabbits 11.6 13.6

Further detailed information is available in The Atlas of Nutritional
Data on United States and Canadian feeds [82].

Regional food values for selected wildlife species are as follows [27]:


UT CO WY MT ND
Elk good good good good good
Mule deer good good good good good
White-tailed deer ---- good good good good
Antelope good good good good good
Upland game birds good ---- good ---- fair
Waterfowl good ---- good ---- good
Small non-game birds good ---- good good fair
Small mammals good ---- good good fair
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Occurrence in North America

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AL AK AZ AR CA CO CT DE FL GA
HI ID IL IN IA KS KY LA ME MD
MA MI MN MS MO MT NE NV NH NJ
NM NY NC ND OH OK OR PA RI SC
SD TN TX UT VT VA WA WV WI WY
AB BC MB NF NT NS ON PE PQ SK
YT MEXICO
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Other uses and values

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Alfalfa is a highly valued agricultural species due to the quality of
hay it produces, its soil-conditioning properties, and ability to fix
nitrogen. It is valued for the ability to fix nitrogen during drought
when other legumes are not nodulated or not actively fixing nitrogen
[57]. It is excellent as pasture for swine, and is used as pasture for
cattle and sheep, despite the hazard due to bloat. Bloat is reduced when
alfalfa is planted with perennial grasses [50,110,114].

Alfalfa is a primary honey plant in North America [53,114].

Alfalfa is a recommended component of vegetational snow fences: trees,
shrubs, and forbs planted alongside highways and railroads to reduce
snow drift on the road. Alfalfa contributes wildlife forage and helps
catch and store snow [107].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Palatability

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Alfalfa is highly palatable to all classes of livestock and big game
species [27,32,50,110].
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Phenology

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More info for the term: cool-season

Alfalfa is generally considered a cool-season species, although
succulent growth can take place through the summer. Growth begins early
in the spring [84,119]. Flowering takes place from May to October,
depending on latitude [37].

Some reported dates for anthesis are as follows [27]:

Utah June-August
Colorado May-October
Wyoming June-September
Montana June-August
North Dakota June-September

Alfalfa can remain green throughout the summer, and dies back in the
fall with heavy frost. There is a critical period in early fall for
transfer of food reserves to the roots [50].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Plant Response to Fire

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More info for the terms: cool-season, moderate-severity fire, prescribed fire

Alfalfa fields that were burned to control insect pests were monitored
for soil changes and plant response. The root systems of the plants
were not adversely affected by the fire, and subsequent crops were
similar in appearance and productivity to that of unburned control
plots. Soil preburn conditions (organic matter and nitrogen) were
attained within 160 days [28]. Canopy coverage of alfalfa increased by
the end of the first growing season following a prescribed fire in May
but showed no significant difference from unburned controls in the
second growing season (which may be attributed to the low precipitation
that year) [85]. Mixtures of cool-season grasses and alfalfa and/or
sweetclover respond best (in productivity) to prescribed fires from
March to June. The lowest response by alfalfa is to late summer-early
fall fires [52,65,85].

In a study of individual plant responses to a spring fire in a tallgrass
prairie stand, Pemble and others [87] found that a moderate-severity
fire resulted in a slight decrease in the amount of flowering (flowers
per plant and plants in flower) in alfalfa.
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Post-fire Regeneration

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More info for the terms: ground residual colonizer, herb, rhizome, secondary colonizer

Rhizomatous herb, rhizome in soil
Ground residual colonizer (on-site, initial community)
Secondary colonizer - off-site seed
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Regeneration Processes

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More info for the terms: formation, scarification, seed

Alfalfa is obligately insect pollinated. Bees are the major insect
pollinators of alfalfa. Leafcutter bees (Megachile rotundata) and
alkali bees (Nomia melanderi) are efficient pollinators. Honeybees
(Apis mellifera) also visit alfalfa flowers but are not as efficient for
pollination [50].

There are approximately 200,000 seeds per pound (441,000 seeds/kg) [50].
On average, 45 to 73 percent of seeds are hard and require scarification
for efficient germination [116]. The percentage of hard seeds varies
with the area producing the seed. In warmer climates, such as southern
California, the number of hard seeds is around 20 percent; in cooler
areas in Washington, the amount of hard seeds is around 40 to 50
percent. Similarly, lower altitude areas have lower proportions of hard
seed than corresponding higher altitudes [43,25]. The most common
method for scarification is mechanical means [93]. Hard seeds became
permeable to water after 4 minutes at 219 degrees F (104 deg C) [90].
Radiation treatments were also effective in rendering hard seeds
permeable; radio frequencies were found to be the most efficient [113].
Busse [10] found that extreme cold also efficiently releases seed for
water uptake.

Seeds can be long-lived. Seed stored in unheated sheds attained 81
percent germination after 19 years [54]. In soils previously unoccupied
by rhizobial nitrogen-fixers the seeds need to be inoculated with
Rhizobium bacteria for root nodule formation nitrogen fixation [40,110].

Seedlings of alfalfa are not very aggressive, but established plants are
very competitive, especially the creeping rooted varieties [50].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Regional Distribution in the Western United States

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
3 Southern Pacific Border
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Successional Status

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More info for the term: cover

Alfalfa is probably not shade tolerant. In a study of alfalfa planted
on chained aspen parklands, alfalfa cover decreased steadily as
overstory canopy increased [7].



Alfalfa establishing on an old roadbed in a sagebrush community. ©2006 Louis-M. Landry.

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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/

Synonyms

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Medicago sativa forma alba Benke. [37]
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Taxonomy

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More info for the term: diploid

The currently accepted scientific name for alfalfa is Medicago sativa L.


Alfalfa is considered a species complex, with many
subspecies. Diploid and tetraploid forms are both common,
though all alfalfa cultivars are tetraploid [100]. Subspecies
that may occur in North America are [116]:

Medicago sativa L. subsp. caerulea (Less. ex Ledeb.) Schmalh
Medicago sativa L. subsp. falcata (L.) Arcang., yellow alfalfa
Medicago sativa L. subsp. glomerata (Balb.) Rouy
Medicago sativa subsp. sativa
Medicago sativa L. subsp. × tunetana Murb.

Medicago sativa readily hybridizes with Siberian alfalfa (Medicago
falcata). The intermediate form, variegated alfalfa, is named Medicago
sativa media [37]. Some authors consider the hybrid a separate species,
Medicago media [50,110,113]. An alternatively used name
for the hybrid is Medicago x varia Martyn, or M. s. subsp. x varia (Martyn)
Arcang. [100,129].
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Value for rehabilitation of disturbed sites

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More info for the terms: animal unit month (AUM), competition, cover, forbs, forest, reclamation, shrubland, tree, wildfire

Alfalfa is widely used for rehabilitation of overgrazed rangelands. It
is recommended for improvement of both wildlife habitat and livestock
ranges in many areas, especially in the drier western states
[32,77,106,114,127]. Many authors report at least short-term forage
yield increases when rangelands are seeded with alfalfa and grass
mixtures [42,71,99]. It is used in interior forests as part of
erosion-control projects. Compacted soils also benefit from alfalfa in
plantings because alfalfa has deep roots that will grow vigorously in
compacted soils.

There is a general concern about introducing species into ecosystems;
however, nitrogen-fixing species can be a way to facilitate invasion of
native plants that have higher soil nutrient requirements than are
present [33]. Under suitable conditions alfalfa can survive and
increase on rangeland in Utah for 10 years or more [58]. It has been
found to be long-lived and productive in semiarid pastures, persisting
for 25 years or more, with successful self-seeding at rates sufficient
to replace mature plants dying from disease, rodent damage, or
environmental stress [96]. It reseeds on sites with as little as
11 inches (28 cm) of precipitation [96]. Areas in Utah planted with
grass and alfalfa mixtures are estimated to have increased rangeland
productivity from 3.53 acres (1.41 ha) per animal unit month (AUM) to
1.32 acres (0.53 ha) per AUM. Overall, reseeded ranges have resulted in
improved weight gains and performance for cattle and sheep, resulting in
a net economic gain (after costs of reseeding) [96]. 'Ladak' alfalfa
was seeded with other grasses and legumes on mountain meadows in poor
condition to improve productivity and provide forage for livestock and
wildlife, and to provide sage grouse summer habitat [31].

Seeding mixtures for revegetating areas damaged by wildfire often
include alfalfa [32]. Use of alfalfa and other seeded species for
erosion control may, however, have a negative effect on the
establishment of tree species. In sugar maple (Acer saccharum)-hickory
(Carya spp.) forest regions of Quebec, alfalfa was found to contribute
to the inhibition of tree establishment, either through direct
competition or by encouraging rodent populations that damage tree
seedlings [15].

Alfalfa is recommended for seeding mined soils to reduce erosion,
increase forage value, and as a soil conditioner. On a surface-mined
site in an eastern Montana ponderosa pine savanna, alfalfa was broadcast
seeded in a mixture of perennial grasses and forbs. Alfalfa and
sweetclover (Melilotus spp.) produced a total of 424 pounds per acre
(475 kg/ha) on grazed sites in 1975 and alfalfa produced 1,449 pounds
per acre (1,623 kg/ha) on grazed sites in 1978. Thus, alfalfa can
persist for at least a few years in this habitat and produce good
quantities of forage [24]. On strip-mined soils in Illinois, a 15- to
20-year-old stand of brome grass (Bromus spp.) and alfalfa had no
detectable soil profile development. This plot was plowed and reseeded
with a mixture of grass and alfalfa, and established 59 percent cover of
alfalfa. Usable forage after 2 years of growth resulted in productivity
of 5,796 pounds per acre (6,490 kg/ha) for alfalfa [24]. In the first
reported instance of moose activity on reclaimed mine spoils, sites that
were planted to alfalfa, clover (Trifolium spp.), and grasses were found
to have a higher incidence of moose use than the untreated adjacent
forest and shrubland, although the amount of difference was small [91].

Alfalfa is used for revegetation projects on many mined sites in the
western United States, and primarily in northern Illinois and similar
areas where the mined soils do not require additions of lime or
fertilizer [119]. Reasonably good establishment can be expected as long
as there is sufficient precipitation (a minimum of 10 to 12 inches [28
cm]) and soil conditions are taken into account [13,91]. In a study on
coal mine reclamation in Arizona, alfalfa was able to establish on mined
soils but only had moderate performance [22].

In Manitoba, on mixed-grass prairie sites disturbed by military tank
maneuvers, it appears that leaving the disturbed sites alone to return
to native vegetation is just as beneficial as reseeding with mixtures
of grasses and alfalfa [125].
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Sullivan, Janet. 1992. Medicago sativa. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/