**1. Introduction**

Indian hot arid zone covers an area of 32 million ha called 'Thar Desert'. 85 percent of the hot Desert lies in India and the rest of the 15 percent in Pakistan. It represents the most inhospitable arid zone of the world spreading mostly in the states of Rajasthan, Gujarat, Punjab, Haryana, Karnataka, and Andhra Pradesh in India. About 91 percent of the Indian desert falls in Rajasthan covering about 61 percent geographical area of the state. The Aravali hills intersect Rajasthan to the Northeast (semi-arid) and in the West lies the Great Indian Desert 'Thar'. High wind velocity, huge dune, semi-stabilized and stabilized dunes of different nature, high diurnal variation in temperature, scanty and poor rainfall, intense solar radiation, and high rate of evaporation are the main characteristics of the Thar Desert. The natural grasslands lie in Desert areas are highly deteriorated stage with the productivity of only 300–400 kg/ha/year. *Dichanthium*-*Cenchrus*-*Lasiurus* type grasslands are associated with sub-tropical, arid, and semi-arid regions comprising the northern portion of Gujarat and the whole of Rajasthan excluding the Aravalli

ranges in the South, western Uttar Pradesh, Punjab, Haryana, and Delhi State between 23 and 32o N and 68 and 80°E. The principal perennial grass species of such grasslands are buffel-grass (*Cenchrus ciliaris*), birdwood grass (*Cenchrus setigerus*), marvel grass (*Dichanthium annulatum*), khavi grass (*Cymbopogon jawarancusa*), bermuda grass (*Cynodon dactylon*), wire grass (*Eleusine compressa*), sewan grass (*Lasiurus scindicus*), pan dropseed (*Sporobolus marginatus*), *tantia* (*Dactyloctenium sindicum*), halfa grass (*Desmostachya bipinnata*) etc. [1]. The dominant perennial grass *i.e.* indigenous sewan grass is popularly known as the "King of Desert grasses". Sewan grass (*Lasiurus scindicus* Henr.) belongs to the family *Poaceae* is native to dry areas of North Africa, Sudanese and Sahelian regions, East Africa and Asia. It is highly tolerant to drought but should be protected from the wind in the early stages of the establishment [2].

Sewan grass is a bushy, hairy inflorescence, multi-branched, C4 desert grass and a stout woody rhizome [2, 3] find in wastelands of arid region. The wild form of Sewan grass (*Lasiurus hirsutus*) is a diploid species having somatic chromosome number (2x) 20 however some species of grass are vary with chromosome numbers and polyploidy nature also [4]. Sewan grass is a perennial grass that can live up to 20 years. Fertilization is not necessary because it can be grown through vegetative propagating material such as root slips. Sewan grass forms bushy thickets in sandy deserts where it is used for pasture, hay, and fodder for livestock. It is found in dry open plains, rocky ground, and gravelly soils [5]. It is relished by ruminants but does not stand heavy grazing and disappears when overgrazed [6].

Comparative performance of major grasses (sewan grass, marvel grass, buffel grass, birdwood grass and bermuda grass) of arid region are presented in **Table 1**. Sewan grass has a higher calcium content and lignin than other grasses, such as marvel grass, buffel grass, birdwood grass and bermuda grass. The components of crude fiber are cellulose, lignin and hemicellulose. However, in case of other nutritional properties sewan grass has lower than other grasses but due to its drought resistance ability can grown in very low rainfall condition (lower than 250 mm) and useful for small ruminants such as sheep and goat.


#### **Table 1.**

*Nutritional quality of sewan grass with other major grasses of arid environment.*

*Sewan Grass: A Potential Forage Grass in Arid Environments DOI: http://dx.doi.org/10.5772/intechopen.98801*

Thirty days cutting interval at a height of 15 cm gives the best fresh fodder and dry matter yields. Sewan grass yields 2.7 to 10.5 tonnes fresh forage/ha/year and up to 3.4 tonnes DM/ha in well-established swards [3]. The low yield can be improved by annual seeding of companion legumes such as guar bean (*Cyamopsis tetrangonoloba*) or moth bean (*Vigna aconitifolia*) [7, 8]. Sewan grass is very important in arid environments because it covers soil especially at the top 15 to 30 cm that helps to protect soil transportation or soil erosion [9], and improve soil health due to the continued decaying of roots of the grass. It can be used to stabilize desert dunes and hummocks [2, 3]. In deteriorated rangelands of Saudi Arabia, sewan grass helps to control the low value invasive species *Rhazya stricta* by smothering its seedlings. It is a useful tool to improve rangeland management [10]. However, sewan grass tolerates prolonged droughts, but has not been found growing in higher rainfall zones and faces a serious threat of becoming an endangered species due to changes in the land use pattern and overgrazing [11]. Reseeding arid rangelands with species such as *Lasiurus scindicus* were found more palatable than its native species *Lasiurus hirsutus* and improved the forage resources at degraded Dera Ghazi Khan Rangeland in Pakistan [12]. Sewan grass is a palatable grass for goat, sheep, and camel, but supplementation is required to meet their nutritional requirements [13–15]. Supplementation with crushed guar seeds (*Cyamopsis tetragonoloba*) at 150 g/head increased DM intake and diet digestibility in ewes grazing sewan grass [16]. The studies with different vegetations growing on the wastelands and grazing lands showed that the association of sewan with other vegetations depends on the area and rainfall pattern of the zone. In the Jaisalmer district, its association has been seen with *Elusine compressa* whereas, in Bikaner, it also comes well with *Cymbopogon jwarancusa*. Over the years, people of the desert have evolved a lifestyle around the sewan grass, based on animal care.
