基于分期播种的气候变化背景下水热因子对春玉米干物质积累及产量的影响

为明确气候变化背景下水热因子对春玉米干物质积累及产量的影响，基于分期播种试验引用关键发育期内积温与土壤贮水量作为水热因子的均一化指标，分析春玉米干物质积累及产量形成对水热变化的响应机制。研究表明，积温的增加对生殖生长的干物质积累优势更为明显，灌浆期温度升高更有利于玉米生物量的积累；积温和土壤水分的匹配通过调整干物质积累速率来影响干物质积累，最终影响产量，抽雄—乳熟期的水热均一指数X对产量的影响最大，玉米各发育阶段X对产量影响的程度由重至轻依次为抽雄—乳熟＞拔节—抽雄＞出苗—拔节＞乳熟—成熟。最大干物质积累速率Vm是限制玉米产量的关键，抽雄—乳熟及拔节—抽雄期的干物质积累速率主要通过最大干物质积累速率对产量起作用。 

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.