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St Augustine grass (Stenotaphrum secundatum)

Datasheet

Description
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Common names 

St. Augustine grass, Charleston grass, pimento grass [English/USA]; buffalo turf, buffalo grass [English/Australia]; chiendent de boeuf [French]; pasto de San Agustín [Spanish]; grama Sto. Agostinho, grama-de-jardim, grama inglesa, grama de Búfalo, grama-italiana, grama de costa [Portuguese]; Kuslandbuffelgras [Afrikaans]; 奧古斯丁草 [Chinese]

In the USA, buffalo grass refers to Paspalum conjugatum.

Synonyms 

Ischaemum secundatum Walter

Related feed(s) 
Description 

St Augustine grass (Stenotaphrum secundatum (Walter) O. Kuntze) is a coarse, stoloniferous and creeping perennial grass. It develops quickly and forms dense leafy sods (Cook et al., 2005). Stems are branching from numerous nodes and may be up to 50 cm tall (Ecocrop, 2010; FAO, 2010). The leaves are glabrous, blue-gray rounded blades, 3-15 cm long and 3-12 mm wide. Inflorescences are 4-15 cm long, spike-like panicles. St Augustine grass produces very few viable seeds and is usually propagated vegetatively. Inflorescence segments are able to float in saline water for short periods, allowing short-range dispersal by ocean currents (Cook et al., 2005).

St Augustine grass is generally used as pasture grass, hay or silage. It is very helpful in providing ground cover under trees and to control erosion on seashores exposed to salt spray (Cook et al., 2005). It is also highly favoured for lawns in warm tropical and subtropical regions (in Florida, 70% of the lawns are made of St Augustine grass) (Casler et al., 2003).

Distribution 

St Augustine grass originated from the shores of the Atlantic Ocean where it is considered as a seashore colonizer because its inflorescences may survive and float for short distances in the sea (Cook et al., 2005). St Augustine grass is now widely spread in tropical seashores of Africa, Australia and south-east Asia. It may be found from sea level up to an altitude of 800 m.

Optimal growth conditions are average day temperatures of 20-30°C, annual rainfall ranging from 750 mm to more than 2000 mm, shaded conditions up to 60%, on soils ranging from sandy loams to light clays, with a pH between 4.5 and 8.5 (Ecocrop, 2010; FAO, 2010). St Augustine grass can withstand temporary flooding and waterlogging as well as alkaline soils, saline soils and saline sprays. It may also withstand conditions of low fertility (Cook et al., 2005; Chen, 1992). It does not tolerate a prolonged dry season (Chen, 1992). St Augustine grass can survive frosts (FAO, 2010).

Forage management 

St Augustine grass is one of the most tolerant and productive grasses in shaded conditions, comparing favourably with Axonopus compressus, Pennisetum clandestinum and Paspalum conjugatum (Roberge et al., 1999; Samarakoon et al., 1990; Shelton et al., 1987). It remains dense where other species elongate and lose vigour (Mullen et al., 1996).

It yields around 5 t DM/ha/year. It withstands trampling, heavy grazing and frequent cuttings (Cook et al., 2005).

Environmental impact 

The vigorous growth habit of Stenotaphrum secundatum provides a tight leaf canopy resistant to weed infestations, even under heavy grazing (Casler et al., 2003; Mullen, 2009; Stür et al., 1990). St Augustine grass improves soil structure, enhances water infiltration rates and increases water-holding capacity, qualities much appreciated during periods of drought (Smith et al., 2002). It also exhibits high persistance after several years under shade in rubber plantations (Ng et al., 1997). It is a suitable companion for legume species (Cook et al., 2005). For these reasons it is much appreciated as a living sod in several cash crops such as coconuts, rubbers and papaya, or vegetables (Mullen, 2009; Smith et al., 2002; Ng et al., 1997).

Nutritional aspects
Potential constraints 

St Augustine grass contain oxalates (1% of DM), but they do not have deleterious effects on stock (Cook et al., 2005).

Ruminants 

St Augustine grass is palatable when young but palatability and digestibility decrease with maturity (Cook et al., 2005). This decrease is not always significant and seems to be less marked than with other tropical species such as Para grass (Brachiaria mutica) (Coleman et al., 1978). St Augustine grass is a sodium accumulator (Stür et al., 1990) and it is, therefore, unnecessary to provide salt to the cattle grazing it. Because St Augustine grass can grow on very different soil types and under a wide range of edaphoclimatic conditions, the results concerning nutritive value are sometimes inconsistent (Mullen et al., 1996).

Fresh grass

St Augustine should be grazed down to 6 cm every second week in order to keep palatability as high as possible (FAO, 2010).

Dry matter intake varies from to 45.0 g/kg LW0.75 in sheep to 85.8 g/kg LW0.75 in steers. Dry matter digestibility varies from 50% in sheep to 61% in steers (Samarakoon et al., 1990Coleman et al., 1978).

Due to its low nitrogen content, animal production from pure St Augustine grass pastures is low but can be expected to improve when combined with herbaceous or tree legumes such as Desmodium incanum, Mimosa pudica, Vigna hosei, Leucaena leucocephala, Aeschynome americanum, Arachis pintoi, Calliandra calothyrsus or Stylosanthes scabra (Mullen et al., 1996; Stür et al., 1990). In Vanuatu, cattle grazing St Augustine grass/legume pastures reached a weight gain of 0.52 kg/head/day (Mullen, 2009).

Hay

In shaded conditions, St Augustine grass hay (dry chaff) has a higher feeding value than forages such as kikuyu grass (Pennisetum clandestinum) and should, therefore, be valuable in plantation agriculture. Shade increases the proportions of leaf in St Augustine grass (45% to 57%) and stem (4% to 11%) and decreases that of dead material. Voluntary intake is also increased in sheep from 45 to 54 g/kg LW0.75. Dry matter digestibility is not statistically increased (50% vs. 53 %), but shade increases the intake of digestible dry matter (19 to 22 g/kg LW0.75) in sheep (Samarakoon et al., 1990).

Dehydrated grass

In tropical and subtropical areas where air humidity and rainfall during the primary growing season are too high, forages cannot be dried and conserved as hay. Dehydration at 148°C followed by pelleting has been proposed for St Augustine grass. Steers ingested more dehydrated forage than fresh (88 vs. 78 g OM/kg W0.75), but organic matter digestibility was lower (57% vs. 60%), resulting in similar digestible organic matter intakes. Mean retention time in the digestive tract did not differ between the two forms of forage (Coleman et al., 1978).

Nutritional tables
Tables of chemical composition and nutritional value 

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

Main analysis Unit Avg SD Min Max Nb
Crude protein % DM 6.7 1
Crude fibre % DM 32.5 1
NDF % DM 67.8 *
ADF % DM 38.1 *
Lignin % DM 5.0 *
Ether extract % DM 2.7 1
Ash % DM 3.7 1
Gross energy MJ/kg DM 19.1 *
 
Ruminant nutritive values Unit Avg SD Min Max Nb
OM digestibility, Ruminant % 61.1 *
Energy digestibility, ruminants % 57.6 *
DE ruminants MJ/kg DM 11.0 *
ME ruminants MJ/kg DM 9.0 *
Nitrogen digestibility, ruminants % 30.7 1

The asterisk * indicates that the average value was obtained by an equation.

References

McCullough et al., 1953

Last updated on 24/10/2012 00:45:08

References
References 
Datasheet citation 

Heuzé V., Tran G., Giger-Reverdin S., 2015. St Augustine grass (Stenotaphrum secundatum). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. http://www.feedipedia.org/node/369 Last updated on October 8, 2015, 15:18

English correction by Tim Smith (Animal Science consultant) and Hélène Thiollet (AFZ)