Effects of long-term fertilization on crop yield and indigenous soil nutrient supply in Hexi Oasis of Gansu Province Impact of climate change on water requirement of main crops in irrigated oasis of Hexi corridor Effect of regulated deficit irrigation on soil nitrogen in spring wheat fields Effects of regulated deficit irrigation on soil phosphorus nutrients in spring wheat field Dynamics of ecological footprints of agricultural region in Hexi oasis of Gansu Province Research on the temporal-spatial differences of carbon sources and sinks of farmland ecosystems of Hexi oasis in Gansu Effect of non-tillage with straw mulch on wind erosion in irrigated oases of Hexi Corridor