Abstract:

Based on studying the response of the irrigation spring maize growth stages to climate change in Shiyang River Basin by using the observations data of the irrigation spring maize growth stages from 1981 to 2016 of Wuwei Agrometeorological Experiment Station of Gansu Province, we aim to provide references for optimizing agricultural planting structure, adjusting variety structure and increasing utilization efficiency of heat resources in the region under the background of climate warming. The trend rate, Spearman correlation analysis and the principal component analysis were conducted. The results showed that the sowing stage, milk ripening stage and maturation stage were postponed, while jointing and tasseling stages were ahead of time from 1981 to 2016. The number of days decreased from sowing stage to tasseling stage, increased from tasseling stage to maturating stage of irrigation spring maize, and the number of days of the whole growth period decreased. In most years, the sowing date was earlier than the suitable date (the first day of active accumulated temperature greater than or equal to 10°C) from 1981 to 2008, and the sowing date was later than the suitable date from 2009 to 2016, and the maturating date was earlier than the first frost date in most years. Temperature factor was the most notable during recent 36 years in Shiyang River Basin on irrigation spring maize. The principle components analysis showed that the effects of the advancing of the first day of active accumulated temperature greater than or equal to 10°C, the prolonging of temperature growth stages, the average temperature, the highest temperature and the lowest temperature of the growth stages were more notable than the hours of sunshine.

Key words: Shiyang River Basin, irrigation spring maize, critical growth stages, the number of interval days of growth stages