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:
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.
描述:
be given when fully and rational use of local
climatic resources such as solar radiation, heat and water, while other conditions (such as soil
fertility, carbon dioxide concentration, cultivation level etc.)
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:
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.
描述:
cal changes took place
in China. In the wars lunched against China by France, Japan and the Eight-power
Allied Forces, imperial force made its way into China step by step and China was
transforming itself into a semi-colonial, semi-feudal society.
描述:
od of Warring States
(475-221 B.C.), attracting scholars' attention and becoming one of important schools then.
After Qin Dynasty, scholars determining to study agriculture carried forward good
traditions of Non自is in the Period of Warring States, enriched researching contents and
fields, and enabled Non自is to develop in depth. In finial, those determining to study
agriculture formed a group with researching agriculture as its distinguishing feature. What
the group researched included agricultural ideologies, techniques of farming and cropping,
methods of operation and management, measures of fighting and preventing agricultural
calamities. The whole group showed its own styles in valuing agriculture and concerning
people's livelihood. And those agricultural ideologies, science and technology, methods and
spirits composed Nongjia's culture, the cream of which can afford us lessons to solve
today's new problems.