Lehmann love grass (Eragrostis lehmanniana)

Datasheet

Description

Click on the "Nutritional aspects" tab for recommendations for ruminants, pigs, poultry, rabbits, horses, fish and crustaceans

Lehmann love grass (Eragrostis lehmanniana)

Common names

Lehmann love grass, Lehmann lovegrass, Lehmann's love grass

Species

Eragrostis lehmanniana Nees [Poaceae]

Synonyms

Eragrostis lehmanniana var. ampla Stapf

Related feed(s)

Description

Lehmann love grass (Eragrostis lehmanniana Nees) is a tufted perennial grass. The culms are up to 60-90 cm high with narrow leaves (1-3 mm wide). Panicles are 10-20 cm long, lax and open (FAO, 2011). Its bunch habit is somewhat open in that individuals do not form a compact crown with numerous stem bases. Strains introduced to the United States have prostrate stems rooting at the nodes (Uchytil, 1992). Eragrostis lehmanniana is cultivated for pasture and hay, notably in Southern Africa and Arizona (FAO, 2011).

Distribution

Eragrostis lehmanniana is native to South Africa and was introduced to East Africa and India. It was introduced in the arid South-West USA in the 1930s for range restoration, in order to prevent soil erosion. It provides forage for livestock in areas where native grasses had declined or disappeared as a result of overgrazing, road building or drought. It is now a major plant species, particularly in South-Eastern Arizona (Uchytil, 1992; McClaran et al., 1992).

Eragrostis lehmanniana grows best at 1000-1500 m. It is adapted to semi-arid, tropical and subtropical summer-rainfall areas and is fairly tolerant of drought. In California it grows in a rainfall regime of 250-375 mm and var. chaunantha flourishes in areas of low rainfall of 300-500 mm. Eragrostis lehmanniana prefers light to medium soils of pH 7.0-8.5. It tolerates high pH caused by calcium and magnesium rather than by sodium. Basal leaves remain green throughout the winter in Southern California and stems stay green after autumn frosts, but temperatures below zero may kill established plants (FAO, 2011).

Forage management

Eragrostis lehmanniana should not be too closely grazed and must be well established before being grazed. Only half the annual growth should be grazed off, but it can be continuously grazed for maximum production. However, a late summer rest improved the total available carbohydrates, crude protein and phosphorus contents, and allows the grass to seed (FAO, 2011). In order to limit the detrimental effects of its invasiveness, it has been proposed to use fencing to separate pure Eragrostis lehmanniana stands from native grasslands because cattle selectively remove dead native grass before grazing Eragrostis lehmanniana green growth (Cox et al., 1990).

Eragrostis lehmanniana is a very productive grass. In the USA, it produces almost 4 times more forage than native grasses and potential forage production on rangelands in South-Eastern Arizona increased after its introduction (Cox et al., 1990). In Northern Mexico, Eragrostis lehmanniana is also a more productive forage than native grassland (2.5 vs. 0.6 t DM/ha), making this species a good alternative for the livestock industry (Esqueda et al., 2001). In South Africa, reported yields are 6-7 t DM/ha/year (Fourie et al., 1985).

Environmental impact

Erosion control

Eragrostis lehmanniana is widely used for reseeding rangeland because it gives a rapid soil cover (FAO, 2011). It has been widely used for roadside stabilization and range restoration in the Chihuahuan and Sonoran deserts in the United States (Uchytil, 1992).

Weed

Eragrostis lehmanniana tends to crowd out the more palatable native perennial grasses (Cable, 1971) and can become the dominant herbaceous plant within 15 years after adventive establishment (McClaran et al., 1992). In the 1990s, several decades after its introduction in the United States, it had replaced native grasses on 200,000 ha in South-Eastern Arizona (Cox et al., 1990). Its adventitious spread is not affected by grazing intensity. Faunal diversity can be lower in lovegrass-dominated grasslands than in native grasslands (McClaran et al., 1992).

Nutritional aspects

Ruminants

Nutritive value and digestibility

Eragrostis lehmanniana is generally a low quality grass. In a year-long experiment in Arizona, the protein content of the leaves averaged about 5% DM, below the maintenance requirements for dry cows and dry ewes from May to January, and only met these requirements in spring. However, cattle graze selectively the seedheads, which contains more protein, and maintenance requirements can be met from late spring to late summer (Cox, 1992). In a 2-year trial in the same region, in vitro DM digestibility was found to be low (usually less than 40%) and highly variable, with values as low as 20% in late summer and as high as 50-60% in early summer. Standing hay was only slightly less digestible (-3.5 percentage units on average) than green forage (Renken, 1995).

Higher digestibility values have been obtained in South Africa. Early trials gave in vivo OM digestibility values of 60-65% (Botha, 1938). A more recent study found in vitro DM digestibility values to be in the 48-69% range (average 60%) for green material and 40-58% (average 51%) for dead standing material (Fourie et al., 1985).

Palatability

The palatability of Eragrostis lehmanniana, while variable, is generally low (Cable, 1971). Selective animal avoidance may be partially responsible for its spread in Arizona and Southern Africa (Cox et al., 1990).

Beef cattle

In its native Southern Africa, Eragrostis lehmanniana is a major range grass. In Botswana, its overall nutritive value was considered to be below the minimum required to sustain animal production, reflected by the protein content, which was below 7% during the wet season (Setshogo et al., 2011).

In the United States, Eragrostis lehmanniana's greatest forage value for cattle is its ability to produce more green herbage in the winter and early spring than native grasses. Cattle make greater use of this grass and graze it readily during the fall, winter and spring because the foliage remains green longer than most native grasses. During summer, its palatability is low and it is generally lightly grazed at that time (Uchytil, 1992). Treatment with sulfur-coated urea increased the protein content of the grass, carrying capacity and weight gain in yearling heifers. However, although this treatment was profitable for raising growing beef cattle, it wasn’t for maintenance of a breeding cow herd (McCawley, 1983).

Nutritional tables

Tables of chemical composition and nutritional value

Lehmann love grass (Eragrostis lehmanniana), hay

Avg: average or predicted value; SD: standard deviation; Min: minimum value; Max: maximum value; Nb: number of values (samples) used