描述:
本论文在查阅了大量国外有关农田控制排水减少地表氮污染研究成果的基础上,设计实验方案,在宁夏银南灌区永宁县望远镇西位二队建立大田实验场地,主要观测项目有:地下水位的变化、排水沟排水量的变化、地下水中硝氮量的变化、地下水中氨氮量的变化、排水沟中硝氮量的变化、排水沟中氨氮量的变化。研究成果有: ① 银南灌
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.
描述:
society. The central
Shaanxi Province lies in the northwest inner-land, lacking in water resources. Although
there have been major farmland irrigation projects and perfect management system in
the Qin and Han Dynasty, the times of the Sui and Tang Dynasty, the situation of water
depletion could not be changed radically.
描述:
ogical characteristics of
the crops and people’s production and business activities, largely dominated by light,
heat, water, gas and other climatic factors.