描述:
ainly chooses three aspects, the quantity and quality
of farmland, the land system and agricultural technology, to analysis the fact that the land system,
the land utilization patterns and the selection of agricultural technology are constrained by natural
environment and land resources, accordingly reveal the main-land relationship which is influenced
by natural environment. The thesis is composed of four parts.
描述:
teau the seeding season is cold and little
rainfall. Soil temperature,moisture and fertilizer is an important factor in crop yield. So in this
area dissemination conservation tillage of importance. Most of former researches in
comparison between conservation tillage and conventional tillage. This experimentation
compare with sereval conservation tillage's difference. Through this comparison, wind-water
erosion in the Loess Plateau ecologically fragile areas and application of a reasonable choice
of different measures to provide a reference of farming with a view to achieving the
sustainable and health development of agriculture. In this study, selection of test sites in the
Loess Plateau in northern China typical wind-water erosion area Shenmu, a no-tillage, straw
mulch, plastic film mulching, mulching ridge, ridge of the five kinds of different measures of
conservation tillage experiment, observe ground temperature,soil nutrients,soil moisture,yeild
and soil and water loss.
描述:
ainly chooses three aspects, the quantity and quality
of farmland, the land system and agricultural technology, to analysis the fact that the land system,
the land utilization patterns and the selection of agricultural technology are constrained by natural
environment and land resources, accordingly reveal the main-land relationship which is influenced
by natural environment. The thesis is composed of four parts.
描述:
ed fruitful results.Turfan studies has become an
international famous learning to be on a par with Dunhuang studies.But the study of the language
of Turfan Manuscripts has not received the attention it deserves,especially most of the Turfan
Manuscripts are civilian appliance documents.The value of its language is not only in a high
描述:
gions and nationalities as
it was discovered. As a result, an international learning has taken shape,that is the
Study of Dunhuang, which contains the study of history, religion, culture, spoken and
written languages, geography,ect. See from the angle of spoken and written languages,