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基于~(137)Cs技术的中国北方农牧交错带土壤侵蚀研究
作者: 姜洪涛   来源: 内蒙古师范大学 年份: 2010 文献类型 : 学位论文 关键词: 土壤侵蚀   农牧交错带   ~Cs   示踪  
描述: ttention, but also agriculture and eco-environmental sustainable development important problems. Farming-pastoral Transitional zone in north China, as our county returning farmland to forest and returning cropping land to grassland are the focus areas, natural environment and socio-economic conditions shown a clear transition characterized by the transition zone of the interpenetration and staggered distribution of agriculture and animal husbandry, which is curbing desertification important ecological barrier, but also ecologically fragile belts.
全文:样品,用美国ORTEC公司生产的型号为GMX50P4N型同轴型高纯锗γ探测器探测在不同土地利用方式下的土壤样品中的~(137)Cs含量,测得各土地利用类型中~(137)Cs含量从高到低的顺序为:平草地
汉代西北屯田问题探析
作者: 牟雪松   来源: 青海师范大学 年份: 2010 文献类型 : 学位论文 关键词: 西北地区   汉代   屯田  
描述: governors of HAN Dynasty. The policy was carried out in most area of the west and the north. In DONGHAN Dynasty, it also appeared in the inner area. The thesis is to tell opening up wasteland and analyses the origin and features of opening up wasteland to get the conclusion: Opening up wasteland in ancient times began in War times and was developed fully in HAN Dynasty. Opening up wasteland in northwest area of HAN Dynasty was only a comprehensive policy to defend the country, including the content of politics 、 military and economy. It was t not for the people but for the country. The policy was spread and lasted for a long time. In economy, it promoted the development of agricultural economy in northwest area by bringing new tools and ways of farming, which also joined the relationship between the central area and the northwest. In politics, it laid a solid foundation for the unity of northwest area and the victory against HUN. In culture, it advanced the communication and joint among different races. Meanwhile, it was a base for opening up wasteland by troops and common people in Cao Wei period.
全文:长。在经济上,汉代在西北地区的屯田,开垦了西北的土地,把先进的生产工具和技术带到了西北,促进了西北边疆农业经济的发展,加强了西北地区同内地的经济文化联系;在政治上,为汉朝对匈奴作战的胜利以及统一西域奠定了坚实
家庭联产承包责任制与现代农业的统一性研究
作者: 余保鹏   来源: 华中师范大学 年份: 2010 文献类型 : 学位论文 关键词: 家庭联产承包责任制   农业现代化   现代农业  
描述: People's commune", then later "the agrarian management revolution", the "household responsibility system". Accordingly, each transformation has also had the enormous influence to the agricultural production development. Each correct adjustment of agricultural
全文:新中国成立之后,从“土地革命”到“合作化运动”、“人民公社”,再到后来的“包干到户”,农业经营制度经过了种种变革。相应的,各种变革对农业生产发展都对产生了巨大影响。每一次农业经营制度的正确调整,都
明清及民国时期黑河流域中游地区绿洲化荒漠化时空过程研究
作者: 石亮   来源: 兰州大学 年份: 2010 文献类型 : 学位论文 关键词: 干旱区   黑河流域   明清及民国时期   绿洲化与荒漠化时空过程  
描述: had been also analyzed. The results showed that: 1. In the early Ming Dynasty, the study area had
全文:如下几点: 1.明朝占领黑河流域初期就开始了对这一地区的大规模开发,人工绿洲规模迅速扩大,此后人工绿洲规模开始逐渐萎缩;嘉靖至万历年间,明朝政府重整屯田,人工绿洲规模逐渐恢复并有所发展。 2.清朝时期
西部干旱地区农户旱地种植行为实证研究
作者: 叶晶晶   来源: 南京农业大学 年份: 2010 文献类型 : 学位论文 关键词: 农户   旱地   水资源   决策   干旱风险  
描述: ncentrated v}}ith 85% of the total dry lands. and it is important for the national economy and the countr<0's strategic agricultural growth. Northwest arid areas basically depend on natural precipitation. water shortage has seriously affected the farmers practices. The decision of farmers to plant dry land is a two-stage decision-making behavior: They first have to decide whether to plant dry land, and then decide what kind of crops planted in the dry lands. It is essential to find effective ways to raise the enthusiasm of farmers planting and reasonable arrangements for dry land crop structure. However. ver}} few people study dry land farming practice from the perspective of water shortages.
全文:对农户是否种植旱地的初始决策和如何选择旱地作物种类的二次决策进行实证分析。分析发现,非农收入、土地产权、人均耕地面积在两个模型中都是显著的。土地肥力只对农户初始决策产生显著影响,地块数量、农机具价值
西北旱作农区农作制优先序研究
作者: 成敏   来源: 西北农林科技大学 年份: 2010 文献类型 : 学位论文 关键词: 西北旱作农区   BP神经网络   农作制优先序   抗旱减灾对策?  
描述: est region, which c ombined with the water-saving, agricultural soil and water conservation techniques, and then taken " drought resistance, reduce erosion, increase efficiency" as a principle.
全文:参与及示范等方法和手段,系统总结西北旱作农区农作制类型,并根据西北旱作农区现行农作制模式粮食生产能力、土地生产效率、抗旱能力、经济效益及生态效益五个方面的综合评价,来进行农作制优先序的研究,最后提出
酒泉市特色农业产业发展研究
作者: 伍小玲   来源: 兰州大学 年份: 2010 文献类型 : 学位论文 关键词: 酒泉市   特色农业产业   制约因素  
描述: stics of the basic conditions for the development of agricultural industry in Jiuquan City and, the situation of and constraints in the development of featured agricultural industry, aiming at seeking an approach to futher develop the featured agricultural industry in the city of Jiuquan.
全文:不强、制度建设缓慢以及不断恶化的生态环境等因素成为酒泉市特色农业产业持续快速发展的瓶颈问题。 第四,提出加大科技、资金投入、大力开展农民技能培训、加快农村土地承包经营权流转和全面发展高效节水型农业等突破
隋唐时期青海草原战争与生态环境研究
作者: 来霞霞   来源: 陕西师范大学 年份: 2010 文献类型 : 学位论文 关键词: 生态环境   吐谷浑   吐蕃   青海草原  
描述: t Territories distributed a few mature Minority forces,for example: TuYuhun, Tibet, Party items.
全文:,土地利用方式的轮番替换,开垦、耕种、弃耕、放牧、沙化、再开垦,使草原的生态受到影响。当农耕民族统治这块地区时,开垦种田,当游牧民族主宰这块地区时,弃垦放牧。这些开垦的土地,一旦抛弃,疏松多沙,且地表裸露
隋唐时期青海草原战争与生态环境研究
作者: 来霞霞   来源: 陕西师范大学 年份: 2010 文献类型 : 学位论文 关键词: 生态环境   吐谷浑   吐蕃   青海草原  
描述: t Territories distributed a few mature Minority forces,for example: TuYuhun, Tibet, Party items.
全文:,土地利用方式的轮番替换,开垦、耕种、弃耕、放牧、沙化、再开垦,使草原的生态受到影响。当农耕民族统治这块地区时,开垦种田,当游牧民族主宰这块地区时,弃垦放牧。这些开垦的土地,一旦抛弃,疏松多沙,且地表裸露
中国古代害虫观念与防治技术研究
作者: 龚光明   来源: 南京农业大学 年份: 2010 文献类型 : 学位论文 关键词: 观念   防治技术   农作物害虫   中国古代  
描述: 中国古代以农立国,农业丰歉直接关乎社会稳定、人类幸福。因此,农业害虫一直受到关注,人们不断探索、总结其规律及应对措施。在生产实践中,害虫观念、防治技术在继承的基础上不断发展与更新。不同时期害虫观念的变化对防治政策的制定及防治技术的实施产生深远影响。 古代农业害虫以蝗、螟、好蚄及未知名害虫为主,次数依
全文:早晨沾露不飞、初生不能跳跃的特性捕杀,提出以鞋底蹲地掴搭蝗虫。元代认识到田地荒芜容易滋生害虫,从而主张保持田间整洁,破坏害虫得以产生的环境条件。宋元在继承前代防治技术上有所创新,对深耕耙细防治害虫
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