河南省夏玉米生长季水分供需时空变化特征

水分条件是制约河南夏玉米高产稳产的重要因素，本文利用河南省夏玉米生长季30个农业气象观测站1961～2011年逐日气象观测资料，计算不同生育阶段夏玉米需水量和水分亏缺量，分析其近50a的水分供需条件时空变化特征。结果表明：夏玉米各生育阶段需水量呈显著的下降趋势；各生育阶段之间水分亏缺量没有显著的年际变化。分析各生育阶段水分供需情况，水分亏缺量为正值表明水分供给不足，为负值表示水分有盈余，出苗一拔节期夏玉米水分亏缺量以负值为主，拔节一抽雄期正负交替各占一半，抽雄一乳熟期和乳熟-成熟期以正值为主。空间分布上，夏玉米各生育阶段需水量与各地海拔高度呈显著负相关，全生育期负相关系数为0．799；各阶段水分亏缺量也有一定的相似性，水分亏缺地区主要分布在豫西和豫西北大部，水分较充足的地区主要分布在漯河、南阳、驻马店等地。

Temporal and Spatial Variation About Water Requirement During Growth Season of Summer Maize in He＇ nan Province

Water is one of the important factors that restricts high and stable yield of summer maize in He＇ nan Province. The water re- quirement and water deficit of summer maize in different growth stage were calculated by using the daily meteorological data in 30 agrometeorological observation stations from 1961 to 2011, and the temporal variation characteristics were analyzed in recent 50 years. The results show that the water requirement of summer maize in different growth stage decreased significantly, and the water deficit had no significant change. The positive water deficit value means water undersupply and negative value means water surplus. The analysis about water deficit in different growth stage showed it was negative value mainly from sprouting stage to stem extension stage, and posi- tive value mainly from heading stage to milk stage and from milk stage to maturity stage. The water requirement in different growth stage of summer maize had significantly negative correlation with altitude, and the negative correlation coefficient of the whole growth period was 0.799. The water deficit in different growth stage had some similarity, the water deficit area mainly distributed in the west and mostly northwest of He＇ nan, and the sufficient water area mainly distributed in Luohe, Nanyang and Zhumadian, etc.