Variation of Effective Accumulated Temperature for Winter Wheat in North China Plain over the Past 30 Years

Wang Fang; Liu Hongju; Wu Dingrong; Wang Chunyi; Yao Shuran

doi:10.16765/j.cnki.1673-7148.2017.02.003

Abstract：Climate change and technological progress such as cultivar shift are the major effects to the Effective Accumulate Temperature (EAT) for crops.Under the combined effects,the observed EAT for crops in China has changed significantly over the past 30 years.This paper analyzed the characteristics of regional distribution of ≥3 ℃ EAT for winter wheat in the North China Plain (NCP) and the trends against year and average temperature during different developmental stages under the combined effects of the climate change and technological progress,based on the phenological winter wheat observation and daily-average meteorological data from 65 agricultural meteorological observation station in the NCP during 1981-2012.Results were as follows.1) The distribution pattern of EAT for the duration of sowing to the start of overwintering (S-O) was generally increasing from west to east,with decreasing from north to south for the duration of turning green to heading (T-H),unobvious for the duration of heading to maturity (H-M).The EAT of whole growing period (the duration of sowing to maturity (S-M)) was generally decreasing from north to south.2)The coefficient of variable of EAT in the duration of the S-O was the highest,relative lowest and most stable for the S-M,and with different characteristics in regional distribution.3)The northeast NCP had negative time trends of EAT for the duration of S-O and T-H,south of Henan negative for T-H,and other region mainly had the positive time trends for the four duration,especially significant in the midwest area.4)Besides,the EATs of 3 duration were positive correlation with average temperature except for H-M in some individual stations,and most of stations were significant by the significance test.5) The effect of average temperature during vegetative growth period (S-O,T-H) to EAT was higher than the effect of year to EAT,opposite during the reproductive growth period (H-M).This indicated the effect of temperature change was higher than technological progress to vegetative growth period,and lower to reproductive growth period.