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
全文: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 银南灌区实行控制排水是可行的,而且能够取得一定的节水及环境效益。 ② 在相同条件下(即沟长296m、排水
描述:
siea. Low temperature is the key factor that limits
the growth, colour and appreciatability in winter in the northern of China. Introducing foreign gene
into kale through genetic engineering may create novel variety with cold tolerance. In this study,
BADH(encoding betaine aldehyde dehydrogenase) and TCH(encoding transcription regulation
factors) were used to be transformed into kale with Agrobacterium-mediated transformation.
描述:
conducted full irrigation (CK),
mild regulated deficit irrigation and moderate regulated deficit irrigation with melon varieties
of Ymdi and Yujinxiang in three growth stages including sowing to flowering time, flowering
to fruit expanding stage and fruit expanding to picking time.
描述:
e distinctive features in Western and Eastern of
Qinghai's natural disaster in history which based on the historical materials and studied the
Interaction Relationship Between the natural disasters and social-economic development, we
used the theory and analysis method from the research area of disaster history and agricultural
history, try to have a comprehensive investigation between the natural disasters and
social-economic development in the history of Qinghai.
Firstly, we divided Qinghai into two parts: the eastern and the western, under the study of
the geographical features of Qinghai. We summarized the natural disaster of the eastern part
mainly as flood, drought, hailstone and frost with distinctive features of variety, continuity
and growth accompany while the western is mainly as earthquake and snow disaster with
distinctive features of unexpected and severity.
Secondly
,
as the great influence on agriculture and the resulting changement in
agriculture is most profound, so the progress in agriculture sciences is related to withstand the
natural disaster in some ways. The paper discussed the natural disasters affected Qinghai's
agriculture in history, from the aspect of seed selection
、
production
、
processing and storage
to invest the development of mitigation techniques in this area. And for the livestock we
investigated in two sides bred of livestock and prevention of livestock, furthermore we
invested the mitigation techniques which full of geographical characteristics.
Thirdly, the article investigated the relationship between natural disasters and the
economic fluctuation in Qinghai from the perspective of the change in population and grain
price. And then, we analyzed the influence on regional industrial structure from the aspect of
expansion in rural areas, the relationship between agriculture and animal husbandry,
disaster-relief crop introduction and the structure of animal species. In the view of pastoral
economic exchange, we studied the interaction relationship between the natural disasters and
economic development.
Finally, we studied the interaction relationship between the natural disasters and social
development in Qinghai. What is more, we analyzed the policy which includes grain storage,
relieved and help the people in disaster , reduced taxes to control the disaster in history. We
wish these could be helpful to the prevention and control of natural disasters in Qinghai today.