描述:
e
are scarce
are one of the
and nonrenewable
of city devel
engrave epoch stamp, They are often named "Green Antique" and "Live
opment,
Cultural
relic" by having high ecological, social, economic value, scientific research, high
ornamental and tourist, and historical memorial meaning.
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:
f the
Qingzang plateau.Gannan is adjacent to Qinghai province in west,to Sichuan province
in south,to the southern of Gansu province in east and to the Loess plateau in
north.Mountainous country and plateau are its major landforms types.It is a highest