描述:
elopment of farmer
specialized cooperatives and make them modern agricultural management
organizations which lead farmers to take part in the competition of domestic and
foreign markets
描述:
e. there are a
lot of Poetries about pstoral beauty and
field work in the The Book of Song -s, but we call it for Poetry farming,
Moreover at that time these poems were not Mature In the aspects of the
quantity and quality .
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:Walling和He提出的质量平衡模型及~(137)Cs深度分布的扩散和迁移复合过程物理模型分别计算耕作土壤与非耕作土壤侵蚀速率。兰州不同土地利用类型的土壤侵蚀速率范围为1200-76000t/k m