Ding, L. - State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China; Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland, Qinghai University, Xining, 810016, China 

 Hu, C. - State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China

Jiang, C. - State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China

Zalmen, H. - Newe-Ya'ar Research Center, Agricultural Research Organization, Yishay, 30095, Israel

Grassland is one of the important natural ecosystems in the world, which not only play an important ecological role, but is also the main source for livestock production. Because of overgrazing in many of these lands, degradation is extending, which is an overall key issue in China. The Qinghai-Tibetan Plateau, which is often called the "roof of the world", is known for its high altitude, low temperature and oxygen content, strong ultraviolet radiation and for its short-term grass growing season. This makes it a vulnerable system, while once damaged, it is very hard to recover. Therefore, it is essential to sustain the eco-function of this alpine grassland system. Reasonable grassland management practice is important for maintaining a sustainable healthy ecosystem. As overgrazing is one of the main causes for degradation of grassland, the proper management should take it account the balance between livestock and vegetation components, and it is essential to select an appropriate stocking rate strategy. Optimal production from pastures is gained only when animal needs and the productive capacity of the pasture are balanced. Stocking rate is usually defined as the number of animals per unit area for a given time period, but is affected by a series of factors, such as animal breeds, animal size and weight, animal performance, animal physiological state, climate environment, resources, grass growing rate and biomass and grass grazing tolerance. Therefore, it is challenging to select the optimal stocking rate, and as so it restricts the planning of reasonable grassland management strategies. In addition, forage biomass and its nutritive quality are dynamic and there is no constant stocking rate that is best for all situations. With the fast development of innovative technology and knowledge, models make possible the attempt to determine proper stocking rates and grazing strategies, while taking in account the balance between livestock and vegetation. But most models are complex while using highly detailed simulations input of many parameters, including grassland, climate, forage, animal physiology and weight, cost and policy, which restrict their use and extension. And so, most farmers are not skilled to use these complicated models in practice. The grassland grazing management model, which was developed by an Israeli researcher, Prof. Imnauel Noy-Meir, is simple, which focusing only two basic processes that determine biomass dynamics, including plant growth and animal consumption of herbage, with a second fundamental management tool, grazing deferment at the start of the green season. The two basic factors are adjusted to be conformed to herbage mass to obtain optimum animal production. This current paper tested Noy-Meir's model in a yak grazing system of Qinghai-Tibetan Plateau. The parameters in Noy-Meir's model in this paper were adjusted, based on published and empirical data from the Qinghai-Tibetan yak grazing system in order to analyze the feasibility of using this model for helpful decision making for improving grazing management strategies in alpine grassland in China. The outcome shows that Noy-Meir's model is easier and helpful for planning grazing practices in Qinghai-Tibetan Plateau grassland. In order to improve the precision of Noy-Meir's model, the parameters still need better adjustment based on the specific pasture conditions.