黑龙江省玉米干旱与低温冷害复合逆境对产量的影响

Effect of Drought and Cold Damage Cross-Stress on Maize Yield in Heilongjiang Province

利用1981—2016年黑龙江省玉米农业气象观测站的资料,引入中华人民共和国气象行业标准中水分亏缺指数(K CWDI)、≥10℃积温距平(H)指标,分别对玉米出苗—乳熟期干旱、低温冷害进行判识,规定同一站、同一年内干旱、冷害均有发生为两种灾害复合发生,并分析其时空分布特征,以数理统计方法构建K CWDI和H与玉米产量的关系模型,同时应用比较方法探讨两种灾害单一发生及复合发生的温水逆境对玉米产量的影响。研究结果表明:1981—2016年,研究区玉米出苗—乳熟期K CWDI、H的变化较好表达了研究区水资源空间配置特征及气候变暖趋势;分析期内,研究区玉米出苗—乳熟期累计发生单一干旱242站年,单一冷害76站年,干旱、冷害复合发生91站年;干旱、冷害复合发生随时间呈减少趋势,20世纪90年代中期以前密集发生,之后发生频率下降,空间上呈西多东少趋势,松嫩平原西部为频发区;玉米出苗—乳熟期H和K CWDI与玉米单产存在显著或极显著的相关关系(P<0.05或P<0.01),在一定温度、水分范围内,H减少、K CWDI增大,玉米单产呈下降趋势;总体上,存在干旱、低温冷害单一发生或复合发生程度愈重则单产愈低的趋势。比较干旱、低温冷害复合发生和单一发生对玉米单产的影响可见,复合发生中干旱(低温冷害)的时间、日数、程度等与单一发生的干旱(低温冷害)相当时,则干旱(低温冷害)与低温冷害(干旱)复合发生对玉米单产的影响呈加重趋势。

Based on the observation data from agrometeorological stations from 1981 to 2016 in Heilongjiang Province,the indicators of water deficiency index(K CWDI)and accumulated temperature anomaly≥10℃(H)from the People’s Republic of China meteorological industry standards,this paper assesses the drought and cold damage to maize during emergence-milk ripening stage separately,and stipulates the drought and cold damage cross-stress occurs at the same station in the same year.Besides,the temporal and spatial distribution characteristics of it are analyzed.The relational model between K CWDI,H and maize yield is constructed by mathematical statistical method,and the effects of single drought,single cold damage or drought and cold damage cross-stress on maize yield are investigated by comparative method.The results show that the changes of K CWDI and H are consistent with the spatial distribution of water resources and climate warming trend in the study area.During the analysis period,the sum of years of drought was 242 station years,and the sum of years of cold damage was 76 station years,while the sum of years of drought and cold damage cross-stress was 91 station years during maize emergence-milk ripening stage in the study area.The occurrence of drought and cold damage cross-stress presents a decreasing trend,and its appearance was high before mid-1990.After that,the frequency got to decline.The occurrence of drought and cold damage cross-stress in the west is higher than that in the east,and there is frequent drought and cold damage cross-stress in Songnen Plain.Correlation amid H,K CWDI and maize yield is significant(P<0.05 or P<0.01)in maize emergence-milk ripening stage.In a certain range of temperature and water condition,H decreases and K CWDI increases,which is unfavorable for the increase of maize yield.On the contrary,increasing temperature and decreasing water deficit is advantageous to maize yield increase.In general,there exists a trend that the more severe the degree of single drought,single cold damage or drought and cold damage cross-stress is,the lower the yield would be.Comparing the effects of the single drought(single cold damage),and combined occurrence of drought and cold damage on maize yield shows that when the time,days and degree of the single drought(cold damage)is equivalent to drought(cold damage)in combined occurrence of drought and cold damage,then the drought is superimposed with cold damage(drought),which means the trend of its disadvantageous effect on maize yield is increasing.