Experiment on Rotational Grazing System in Stipa breviflora Desert Steppe

The comparison of rotational and season-continuous grazing systems were conducted in Stipa breviflora desert steppe with sheep in five years and the characteristics of vegetation,soil,and livestock performance were measured in order to get the theoretical basis for the rational utilization of rangeland.The results showed that rotational grazing is benefit to the sheep production,especially in the situation of short of forage supply,the sheep production was similar in both grazing systems in the sufficient forage supply,the good sheep performance in rotational grazing system is due to the comprehensive effects of grazing behavior of sheep,forage biomass available,contents of nutrient matter of forage ,and the climate,but the change of pattem on grazing behavior of sheep is the most important factor.The idling time and grazing time in rotational grazing system were less than in season-continuous grazing system,which resulted in less selectivity of sheep for plant species,and higher transformation efficiency of sheep for forage in rotational grazing system than in season-continuous grazing system.Therefore,the liveweight of sheep in rotational grazing system was higher (P0.05) than in season-continuous grazing system.Herbage biomass available of pasture is a useful index in the evaluation of grazing system.When the herbage biomass available was below 24g/m 2 the intake of sheep limited and rotational grazing system was benefit to sheep production.Vegetation and soil were not sense to grazing system in short period.