Introduction Experiment And Grassland Resowning Scheme For Main Implement Areas Of "Restoring Grassland From Over-grazing" Project In Gansu Province

To ensure resowing item of "restoring grassland from over-grazing" project rightly implemented, and play its important technical role in vegetation recovery and improvement, we continued studies on filtration and optimization of resowing technique of adaptable grass varieties. Based on natural condition and grassland status of these key implement counties of "restoring grassland from over-grazing" project in Gansu province, such as Luqu, Maqu, Xiahe, Zhuoni, Diebu, Tianzhu, Sunan et al., we collected existent materials and did regional experiments, and completed grassland resowing scheme of major implement areas in Gansu province.Regional experiments are conducted in alpine meadow and agro-pastoral ecotone of Gannan, and alpine grassland of Qilian Mountain. In alpine meadow of Gannan, we selected out the herbage varieties that could be planted and extended in this experiment area and in similar climate areas through observation on development stage, cover and overwintering condition of chosen grasses and assessment and comparative analysis of their growth height and grass yield. In agro-pastoral ecotone, we observed and determined the emergence, tillering, heading, flowering, ripening and withering of tested grasses and the emergence, branching, budding, floweing and withering of tested legumes, determined their height, yield and wintering rate, and found that Elymus sibiricus,_Elymus excelsus, Longdong alfalfa were optimal herbage that are suited to be planted and extended in Gannan ecotone through two-year introduction experiments and observation and comparison of grass yield and wintering rate of these 13 varieties. In alpine grassland of Tianzhu and Qilian Mountain of Sunan, Poa pratensis, Poa crymophila, Jilin Elymus sibiricus, Elymus nutans, Elymus sibiricus are preferentially variety candidates for establishing sowning pastures and implementing grassland resowing in these areas through observation on the whole growth periods of tested varieties 2005-2006 and determining grass yield in 2006.Through comprehensive comparison and analysis on above experiments, we select out grass varieties suited to be planted and extended in different areas and compile out a grassland resowing scheme of major implement areas in "restoring grassland from over-grazing" project of Gansu province, including variety choice, application proportion and technique regulations, to provide technique support for implement of "restoring grassland from over-grazing" project.