The evaluation of grassland resources and its nutrition in therecovering degraded grassland

Abstract：From June to October 2008, the field investigation and surveys on the enclosed (for seven years) recovery grassland of natural grazing pastures were conducted to analyze production capacity, pasture resources and dynamic changes of vegetation community nutrition at Dalinuori Town, Keshiketeng Banner, the Inner Mongolia Autonomous Region. Furthermore, the feeding value and optimum carrying capacity of the pasture were also evaluated to provide a theoretical guidance for establishing scientifically a grazing management system of enclosed recovery pastures and promoting the sustainable development of grassland animal husbandry. The results showed that the grassland ecosystem had been recovered to Leymus chinensis and Stipa krylovii steppe communitybased from Artemisia frigida steppe after 7 years of enclosed restoration. The community characteristics of vegetation were improved; average coverage was 37.5%, density was 184.6 plants/m2, average height was 18.3 cm, fresh biomass was 154.3 g/m2 and the highest yield was 358.6 g/m2 in the whole growth period. The forage maintained high levels of CP, EE, TDN and ME; averaging 12.06%, 1.87%, 57.4% and 8.31 MJ/kg respectively. Based on forage yield in the warmseason yield carrying capacity was calculated to 0.656 hm2/sheepunit. However, according to forage and sheep nutrition indicators (CP, EE and TDN) supplydemand relation; the nutrients carrying capacity were estimated to 0.513， 0.802 and 0.774 hm2/sheepunit respectively. Therefore, the degraded grassland was resumed after 7 years of enclosed restoration; with higher grassland carrying capacity, excellent feed resources and better forage nutrition value compared with the control. The enclosure recovery grassland can be moderately grazed for sheep and cattle.