1961—2012年中国棉花需水量的变化特征

利用中国三大棉区230个气象台站的地面气象资料和103个农气观测站的棉花生育期资料,采用联合国粮食与农业组织推荐的方法计算了研究区域内1961—2012年棉花全生育期和不同生育阶段的需水量,并探讨了棉花不同生育阶段缺水量和水分盈亏指数的变化。结果表明：1961—2012年我国棉花全生育期需水量和缺水量整体呈下降趋势;需水量在开花到吐絮期总体呈下降趋势,而在播种到开花、吐絮到成熟阶段基本无变化;缺水量在播种到吐絮期总体呈下降趋势,而在吐絮到成熟期基本没有变化。比较三大棉区典型站点棉花水分盈亏情况,研究区域内棉花全生育期和各生育阶段的有效降水量均不能满足棉花的需水要求,其中西北棉区棉花各生育阶段的缺水状况最为严重。研究可为中国棉花种植区域的农业用水及合理灌溉提供科学依据。

Variation Characteristics of Water Requirement of Cotton in China during 1961-2012

Based on the observation data from 230 meteorology stations and cotton phenology data from 103 agrometeorological stations in the three major cotton producing regions of China, the water requirement of cotton throughout the whole growing period and in each growth stage during 1961-2012 were estimated by using crop coefficient and FAO Penman-Monteith equation. Further, the water deficit and water budget index in each growth stage of cotton were analyzed in the study area. The results showed that the average water requirement and water deficit in northwest region during 1961-2012 were greater than that in Huang-Huai-Hai and Yangtze River Valley regions. The average water requirement and water deficit from flowering to boll opening stage was the highest, followed by that from sowing to flowering stage, and that from boll opening to maturity stage was the least. The water requirement and water deficit during the whole growing period from 1961 to 2012 decreased in this region. The water requirement decreased in the period from flowering to boll opening stage, but it had no change from sowing to flowering stage and from boll opening to ripening stage. The water deficit of cotton decreased in the period from sowing to boll opening stage, but it had no change from boll opening to ripening stage. Comparing the water budget index of typical stations in different study regions, the effective precipitation during the whole growing period and the different growth stages all couldn’t meet the demand of cotton, and the most serious water shortages occurred in the northwest region. This research can provide the basic scientific support for better agriculture water use and reasonable irrigation in the cotton growing regions of China.