描述:
ch as the important town
of the Silk Road, multi-ethnic coexistence and the border district administrative center.
In order to ensure normal exchange between the East and the West, frequent contact
among ethnicities, and effective administration in He-xi area, it was extremely
essential to establish city defense. Therefore, the Tang government built the city
defense system that was mainly military defense and based on social balance. Mainly
included the screen protective system of Army, Shouzhuo, City, Town, Shu, etc.,
which had some focal point and very wide and located out of the cities; Three layers
external protective system that was composed of a deep ditch to round every city,
sheep and horses cities, city wall; Multiple structure system such Luo city(outer city),
Zi city(inner city), fang(residential area), Shi(markets), and so on; Garrison inside
cities and out of locality system; Feng, Yi and other information systems; General's
office person of ability system; Warehouse reserve and social balance system.
Because of the important geographical position strategic and the special social
security problem, the He-xi Prefecture and county city defense had formed Trinity
characteristic with the national defense and the security defense. The city defense
soldiers had a hand in Tuntian to bring about He-xi area’s agricultural advance; A
large number of people of city defense formed the consumer market, had promoted
the prosperity of the commerce; The city defense ensured traffic and military
assistance, made He-xi Prefecture and county cities become the rear base to
administer Central Asia. However, the city defense had its limitation, such as
impotent military might at times (it offered an opportunity of Tibetan expanded in
north-west area), because of the condition between the country and the locality. It, to
a certain extent, had influenced on the valid function of city defense.
描述:
duction in the area is
restricted by disadvantageous natural resources and environmental conditions,
including low arable land area per capita, frequent drought events and a landscape
dominated by mountains. Forage crop rotation systems could improve soil fertility,
increase crop外eld and provide quality forage supplies for livestock production.
Additionally, their adoption is considered a suitable means to advance sustainable
agriculture development. In this study, the role and status of forage crop rotations in
Tianshui city were studied.
描述:
lions of farmers, greatly emancipated and
developed the rural productive forces, and fundamentally improved the majority of farmers'
production and living conditions. The economy and society of rural area in China has undergone
描述:
by human and god. What is
more important, Dayu spirit and culture due to him have a immeasurable effect on the
formation process of Chinese civilization, on the political awareness of feudal state, on the
lower-level life of the common people, and on the aesthetic culture of literature and art.
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.