The problem of herbicide-contaminated farmland soil is becoming increasingly serious in some areas of China with the rapid development of economy and the acceleration of industrialization process. The butachlor tolerant of ryegrass(Lolium perenne L.)and astragalus(Astragalus sinicus L.)are studied. The main results are as follows:Astragalus seed is more tolerated toxicity of butachlor than ryegrass seed. The tolerance test showed that the ryegrass root length can not change,when concentration of butachlor is higher than 5 mg/L except 30 mg/L,the height of the ryegrass seedling can not change when concentration of butachlor is higher than 15 mg/L. But astragalus root length and seedling height can not change,when concentration of butachlor is higher than 15mg/L.

<正>生态环境对人类的适应是通过自然力实现的,要求人类必须遵从适者生存的自然法则,否则对人类的惩罚就不可避免,只有二者交互共存才能实现可持续发展。中国要实现又"富"又"美丽",必须坚持走可持续发展道路。努力推进环境友好学校建设,对于发展生态文化、践行生态文明,构建资源节约型、环境友好型社会,具有十分重要的基础性意义和不可替代的作用。一、环境友好的生态文化考量

Three pot experiments,which included two fertilization experiments(N or P fertilizer) with 10 levels of 0,0.5,1,2,4,8,16,32,64,128 g·m-2 and a water supply experiment at 11.5,12.7,14.3,16.4,19.1,22.9,28.7,38.2,57.3,114.6 mL·cm-2,were conducted to evaluate effects of N or P fertilizer and watering on biomass and nutrient allocation of Leymus chinensis in this study.The results showed that with increase of N and P application,biomass and nutrient contents of both aboveground and underground of L.chinensis tended to increase firstly and then decrease,while root-shoot ratios showed decreasing trends.The responses of biomass and nutrient contents of both aboveground and underground to water gradients were similar as those to the nutrient gradients,but the root-shoot ratios did not show significant change in the water supply experiment.The biomass and nutrient contents of aboveground were higher than those of underground during growth season(in August),whereas there was a contrary trend at the end of growth season(in October).These results indicate that changes in N,P and water availabilities in soil could affect the accumulation of biomass and nutrients both in aboveground and underground of L.chinensis substantially;more biomass and nutrients were allocated to abovegroud in August and then transferred to underground at the end of growth season.Therefore,global climate change changed growth and nutrient use of plant,which will further influence structure and function of the plant-soil system in Inner Mongolia temperate steppes.

Taking 10-year enclosed natural grassland,grazing land and abandoned land of Namusila Nature Reserves in Zhangwu as study objectives,a comparative study was made for the community characteristics of the three communities in growing season.