A Study On Ecological And Economic Efficiency In Forage-crop Rotation System In Tibet Farming Area

With the strategic development of the western China and the fast adjustment of production structure in agriculture and animal husbandry, large emphasis has been given to planting grasses to feed domestic animals over Tibet. However, due to the lower extent of collective and massive production, farmers have not recognized the importance of planting grass, consequently, only small coverage of land around houses are used to plant grass. In addition, animal husbandry production is bundled with the agriculture production; there is evidently lack of food supply for animals during the winter and spring. These factors limit the development of the favorable production in Tibet. In the meantime, most agricultural fields are used for a single variety such as wheat and barley production, over a long period. Sustainable land usage is largely overlooked and the land is exploited to a great extent. As a result, nutrients in the soil become unbalanced, productivity become extremely lower. However, poor land, lower organic fertilizer and arid climate are fatal weaknesses. Arid climate and poor soil quality become major obstacles for the development of wheat production. Realizing these weakness, importing grass into agricultural fields and shifting between wheat and grass have great advantage of combining land usage with land protection. By doing so, we could not only take advantage of large coverage of agriculture fields, but also avoid the unfavorable climate conditions.In this dissertation, we intent to prove shifting grass and wheat planting has irreplaceable importance in the process of adjusting agriculture structure in Tibet, it has enormous economic, social and ecological benefits. Results of this research will provide a reliable theoretical base for the adjustment of agriculture structure in Tibet, developing regional exclusive product, building a sustainable ecosystem with harmonic relationship between human and nature. The results showed as follows.1. Planting leguminous forage can not only provide a large amount of high quality...