Response of Hydrothermal Factors on Dry Matter Accumulation and Yield of Spring Maize under Climate Change Based on Staged Sowing

To clarify effects of hydrothermal factors on dry matter accumulation and yield of spring corn under climate change，response mechanism of dry matter accumulation and yield formation of spring corn to hydrothermal changes was analyzed based on staged seeding experiments to cite accumulated temperature and soil water storage in key development periods as homogeneous indicators of hydrothermal factors.Studies showed that increase in accumulated temperature had more obvious advantages in dry matter accumulation for reproductive growth，and increase in temperature during filling stage was more conducive to accumulation of corn biomass；matching of accumulated temperature and soil moisture affected dry matter accumulation by adjusting dry matter accumulation rate，which ultimately affected yield.Water and heat uniformity index X in tasseling-milk ripening stage had the largest impact on yield，the order from highest to lowest was tasseling-milky mature> jointing-tasseling> emergence-jointing> milky mature-mature.The maximum dry matter accumulation rate Vm was the key to limit yield of corn.Dry matter accumulation rate during tasseling-milk and jointing-tasseling stages affected yield mainly through the maximum dry matter accumulation rate.