Perennial herbaceous Astragalus, a source of forage production in rangelands of Iran

Abstract

The role of different species of Astragalus is important in soil and water conservation, genetic reserve, biodiversity, industrial and medicinal value, and forage production. The genus has been widely spread in different climates due to species diversity and adaptability. Astragalus has increased the vegetative potential of rangeland by increasing soil fertility. Herbaceous species of this genus are highly grazed due to their high protein content and low fiber. According to the reports of the Rangeland Technical Office, the amount of grazing pressure on rangeland is 2.2 times more than the grazing capacity. This amount has been reported up to seven times the grazing capacity in semi-steppe rangelands. Since a large area of rangelands with a rainfall of more than 250 mm has been changed to abandoned drylands, the soil has been exposed to erosion. It seems that more than one ton/ha of forage can be produced by cultivating herbaceous Astragalus in abandoned drylands and degraded rangelands. On the other hand, due to the special characteristics of Astragalus, such as the presence of wide and deep roots, and a relatively large canopy, it is possible to achieve water and soil protection and increase the diversity of species in these areas.