Response Of Main Crops To Climate Change In Northwest China

Climate change has markedly affected global ecosystem and drawn great attention from the governments of various countries and scientists. Agriculture is a main source of the economy and the science and technique levels about agricultural production get behind in China. How will China agriculture cope with climate change? This is an urgent question that is required to study. In this paper, based on long-time observation and experimentation data about weather and Agriculture, response of main crops to climate change is investigated in the northwest of China. The following main conclusions can be drawn from the study:Climate warming made water use efficiency (WUE) of spring wheat and corn decrease in arid areas of northwest China and irrigation water adding quickened this decrease rate. Both climate warming and drying made water use efficiency of potato decrease and precipitation reducing made water use efficiency of winter wheat increase in semi-arid areas of northwest China. In climate warming, water use efficiencies of spring wheat, winter wheat and corn decreased when the supplied water added. And the most WUE in medium supplied water had been found. The key growth phases and water items of WUE of corn and spring wheat were the irrigation water of shooting to milk maturity and flowering to maturity, respectively. But the key growth phases and water items of WUE of winter wheat and potato were the precipitation of squaring, milk maturity and flowering, respectively. A rise in temperature cut down the WUE of spring wheat, winter wheat and corn.A rise in temperature brought forward the seeding time of cotton, spring wheat and corn in spring while postponed the seeding time of winter wheat in autumn. An increase in temperature quickened spring wheat, corn and winter wheat growth and cut down the growth period of these crops. Spring warming made earlier cotton and potato seeding time and autumn warming made later these crops growth stopping time, which extended the growth period of cotton and potato.The temperature is the main factor affecting crop yield in arid irrigated areas of northwest China. Both temperature and precipitation affect crop yield in semi-arid rain feed agriculture areas. A rise in temperature made yields of corn and cotton in favor of heat add and yield of spring wheat decrease in arid irrigated areas and yield of winter wheat living through the winter increase in semi-arid rain feed agriculture areas. And climate warming and drying made potato yield decrease.The seeding acreage of corn and cotton in favor of heat and winter wheat and winter cole living through the winter added and the seeding acreage of spring wheat decreased in climate warming in northwest China. The planting pattern that spring sweat was dominant crop changed to pattern that corn, cotton and winter wheat predominated in arid areas. The planting pattern that wheat was dominant crop changed to pattern that corn, potato, winter wheat and winter cole predominated in semi-arid areas. Climate warming offered this change of planting pattern weather conditions and agricultural activities that people sought more income made this change achieve. This change of planting pattern may bring grain security latency imperilment.Climate warming and drying resulted in a diminishing trend of soil water year after year on loess plateau in northwest China. Precipitation reducing resulted in a decreasing tendency of evaporation of cropland year after year in this region. And the precipitation reducing may be the main climate factor of soil drying year after year on loess plateau.