华北平原限水灌溉条件下冬小麦产量及水分利用效率变化的Meta分析

Change in Winter Wheat Yield and Its Water Use Efficiency as Affected by Limited Irrigation in North China Plain:A Meta-analysis

【目的】定量综合分析华北平原限水灌溉条件下冬小麦产量及水分利用效率的变化。【方法】以现状灌溉情形作为对照,基于47篇公开发表的学术论文中所收集的551对冬小麦产量观测数据与459对冬小麦水分利用效率观测数据,采用Meta-analysis方法对限水灌溉条件下的田间试验结果进行综合归纳,并通过亚组分析探讨了不同灌溉方案、土壤质地和田间管理措施等对产量和水分利用效率的影响。【结果】与现状灌溉相比,限水灌溉条件下冬小麦平均减产10.5%,水分利用效率平均增加4.3%。其中,灌溉3次方案可使得冬小麦稳产增效;在关键需水期灌溉1~2次的方案下,冬小麦的减产率可基本控制在10%以内,水分利用效率提高5%以上,显示出适度减产但效率增加。推荐的冬小麦种植田间管理方案包括:选用"石家庄8号"、"石4185"等节水品种;在10月中旬播种(适当晚播或晚播);种植密度控制为400~600株/m^(2);增加有机肥施用;使用地覆或秸秆覆盖;实施深松耕等农艺节水措施。另外,冬小麦限水灌溉方案更适宜在砂壤土区域进行推广。【结论】限水灌溉下冬小麦减产但增效,适当的田间管理方案可有效降低减产程度,提高水分利用效率。

【Objective】Limited irrigation is a strategy introduced in northern China to alleviate groundwater depletion by marginally scarifying winter wheat yield.The purpose of this paper is to analyze the variation in winter wheat yield and its associated water use efficiency(WUE)following implementation of this strategy.【Method】The analysis was based on experimental studies published in 47 papers;they consisted of 511 pairs of dataset for yield comparison and 459 pairs of data for WUE comparison.In both comparisons,business-as-usual was taken as the control.The effects of different limited irrigation schemes,soil texture and agronomic management on yield and WUE of the wheat were calculated using subgroup analysis.【Result】On average,limited irrigation reduced the wheat yield by 10.5%and increased WUE by 4.3%,with the reduction and increase both depending on irrigation method and irrigation frequency.When the irrigation amount was the same,irrigating the crop three times during its growing season could minimize yield reduction while in the meantime improve WUE.In contrast,reducing the irrigation frequency to twice or once during the growing season of the crop reduced its yield by>10%despite the>5%increase in WUE.To minimize yield reduction due to the limited irrigation,we recommend crop varieties of Shijiazhuang 8 and Shi 4185,with their seeds drilled in the middle of October at planting density of 400~600 plants/m^(2).Also,increasing organic fertilization,straw mulching,coupled with deep ploughing,was found effective to alleviate yield reduction due to the reduced irrigation.The analysis showed that the limited irrigation was more suitable for implementing in sandy loam soils than in other soils.【Conclusion】Increasing irrigation frequency can partly offset the detrimental impact of the limited irrigation on winter wheat yield in the North China Plain in China.Yield reduction can be further reduced by changing some agronomic management practices such as increasing organic fertilization and deep ploughing.