主要生育期气候变化对河南省冬小麦生长及产量的影响

为分析不同生育期气候变化对冬小麦生长及产量的影响,本研究选择河南省30个农业气象观测站1961—2014年气象资料、1981—2014年冬小麦发育期及产量资料,采用数理统计与DSSAT-CERES Wheat模型模拟相结合的方法,分析了冬小麦播种—返青、返青—抽穗、抽穗—成熟3个时期的气候变化特征及其对生育期和产量的影响。结果表明:研究区气候变化的显著特征是播种—返青期日照时数按40.09 h·(10a)~(-1)的速率显著减少(P0.05),返青—抽穗期平均日最高气温和平均日最低气温同时大幅升高。冬小麦幼穗分化随着抽穗前日最低气温的升高按2.9 d·(10a)~(-1)的速率而提前结束,返青前气候变化对后续生育进程有持续影响,气象因子与播种—抽穗期、播种—成熟期持续日数以负相关关系为主。两种分析方法均表明:当前河南麦区播种—返青期气候变化对产量的影响不大,在一定范围内甚至有增产作用,气象因子贡献率平均为0.758;返青—抽穗期气候变化使穗密度和穗粒数平均减少2.74%和3.94%,大于抽穗—成熟期。不同生育期气候变化情景下,冬小麦高产和稳产均受影响,代表站点播种—返青、返青—抽穗、抽穗—成熟期分别平均减产1.6%、6.3%和4.8%,其中播种—返青、抽穗—成熟期影响产量的关键气象因子是日最高气温,而返青—抽穗期是日最低气温。

Effect of climate change on growth and yield of winter wheat in Henan Province

Winter wheat is one of the main grain crops in China. The growth, development and yield formation processes of winter wheat are affected to various degrees by climate change. Henan Province is the main cultivation base of winter wheat. Thus, the intensive analysis of the impacts of climate change on different growth periods of winter wheat is critical for scien-tific study of the positive and negative effects of climate change. Based on the formation processes of winter wheat yield var-iables, the whole growth stage was divided into 3 main growth periods, planting to greening, greening to heading and heading heading to maturity. Daily meteorological data (for the period of 1961–2014) on winter wheat development periods and grain yield (in 1981–2014) in 30 agro-meteorological observation stations in Henan Province were used to analyze the characteris-tics of the main growth periods and the effect of climate change on yield. Through mathematical statistics, the meteorological variables were used to analyze the trend in climatic change, its effect on the development periods of wheat and its contribution rate to grain yield during the main growth periods. Using DSSAT-CERES Wheat crop model, the effect of climate change at different growth periods on wheat yield was simulated. The results showed that the distinct characteristics of effect of climate change in study area was the significant (P < 0.05) reduction in sunshine hours, which was at the rate of 40.09 h·(10a)-1during planting-greening period. There was also a large increase in average maximum and minimum air temperatures, respectively at the rates of 0.484℃ ·(10a)-1 and 0.591℃ ·(10a)-1 during greening-heading period. With increasing daily minimum tempera-ture before heading, panicle differentiation in winter wheat terminated earlier by 2.9 days per decade. Climate change before greening had a continuous effect on the development progresses, with negative correlation between meteorological factors and sustained days from planting to heading and then planting to maturity. The results of two different analytical methods indicated that there was no significant effect of climate change during planting to greening stage on yield in Henan Province. In a certain scope, climate change even had positive effects on grain yield. The average contribution rate of climate change to winter yield variables was 0.758 during planting to greening turning stage. At representative stations, climate change during greening to heading resulted in reductions in kernel density and kernel number, respectively, by 2.74% and 3.94%, followed by 2.46% and 1.87% reductions during heading to maturity. The significant decrease in kernel number due to climate change during greening to heading was the primary reason for the yield reduction. Intensified climate change was harmful to both high and stable yields. Climate change during the periods from planting to greening, greening to heading and heading to maturity led to aver-age yield variations in the representative stations by-1.6%,-6.3% and-4.8%, respectively. Under climate change, the key meteorological variables that influenced yield was daily maximum air temperature during planting-greening and head-ing-maturity periods, and daily minimum air temperature during greening-heading stage.