河南省夏玉米生产水足迹区域差异

Regional differentiation of water footprint during summer maize production in Henan Province

作物生产水足迹是衡量整个作物生产过程中水资源利用状况的综合指标,能清晰地反映出水资源消耗类型、数量以及用水效率,为农业水资源管理评价提供了全新的思路。本研究在计算玉米单产的基础上,分析了1990—2015年河南省6个玉米种植区生产水足迹的时空差异。结果表明:河南省玉米生产水足迹呈现先波动下降后趋于平稳的态势;不同产区的生产水足迹差别较大,其中豫西玉米生产水足迹最高,豫东、豫中南、豫北的生产水足迹低于河南省平均值;绿水是河南省玉米生产需水的主要组成部分,占生产水足迹的80%以上;在时空分布上,均表现为生育期间降水量越低,绿水生产足迹所占比越高;基于对6个玉米种植区水足迹的分析,建议对豫西、豫南等玉米生产水足迹较高的区域,应推广抗逆性强的品种,提高水分利用效率,缩减玉米种植面积,而豫东、豫中南和豫北3个区域玉米生产水足迹较低,属于玉米种植优势地区,应保持或扩大玉米种植面积。

Water footprint during crop production, an aggregative indicator quantifying the utilization of water resource during the whole crop development, clearly reflects the type, quantity, and efficiency of water consumption. This tool provides a new method for assessing agricultural water resources management. Based on the calculation of maize productivity, we evaluated the spatialtemporal variations in six different regions of Henan during 1990-2015. The water footprint of maize production in Henan stayed at a low level after decreasing with fluctuation. The water footprint varied greatly among different regions. The western region of Henan Province had the highest water footprint, while the eastern, mid-southern and northern parts of Henan had lower water footprint than the average value at province level. The major portion （80%） of water footprint during maize production was contributed by green water. Temporally and spatially, the proportion of green water was negatively correlated with the precipitation during maize growth period. Based on the analysis of water footprint of the maizeproducing region, it is a good choice to use the stressresistant varieties to increase water use efficiency, and decrease area of maize planting in the western and southern parts of Henan where water footprint was high. However, the maize planting area should be maintained or expanded in the eastern, central southern and northern parts of Henan where the water footprint was lower.