Abstract:

Contradiction between winter wheat production and water shortage in Haihe Plain is becoming an increasingly prominent problem. It is urgent to establish water limited irrigation system to achieve the coordination and unity of high yield and water efficiency. 2 types of winter wheat varieties were used， including drought-land group （Shinong 086， Jimai 585 and Shixin 828） and fully-irrigated-land group （Shimai 22， Hengguan 35 and Jimai 418） from 2018 to 2020. 2 sowing dates of suitable sowing and late sowing were employed. Each sowing date was treated with 6 different irrigation periods： control group was irrigated twice in spring， one at the 3-leaf stage and the other at the anthesis stage； no irrigation treatment in spring was as control； four primary irrigation treatments were applied in spring， designating as 3-leaf stage irrigation， 4-leaf stage irrigation， 5-leaf age irrigation， and 6-leaf age irrigation. The dynamics of soil moisture and the yield composition characteristics of winter wheat under different treatments were investigated. The major results were as follows： upon water limited irrigation in spring， 0—60 cm soil layer was the primary water supply layer， and dynamics of soil water content （SWC60） significantly affected the formation of wheat yield. 4-leaf stage was the best irrigation period for primary irrigation of winter wheat in spring， and its degree of drought stress before irrigation was low， and the SWC60 was lower than 60% until the end of milk maturity period after irrigation， and its level of drought stress was also relatively light. Under water limited irrigation in spring， the yield of winter wheat decreased significantly， and the yield decline of dry land group was lower than that of water land group. For the overall performance of single irrigation treatment with different leaf ages in spring， and lowest yield loss was irrigation at 4-leaf age in spring， with an average reduction of about 10%. There was no significant difference between the yield level of primary irrigation treatment in spring and the corresponding suitable sowing treatment. The yield and WUE of 4-leaf stage irrigation treatment in spring were significantly higher than those of other primary irrigation treatments in spring. The spikes， kernel number and 1 000-grain weight were more balanced and coordinated， while achieving the yield level of 7 502.9~8 050.0 kg·hm^?2， WUE reached 17.5~20.1 kg·hm^?2·mm^?1， saving 70.1 mm compared with twice irrigation in spring. This study provided theoretical basis for constructing a precision and efficient water limited irrigation system for wheat in spring.

Key words: winter wheat, water-limited irrigation, yield composition, dynamics of soil water content, leaf stage

摘要：

海河平原冬小麦生产与水资源匮乏的矛盾十分突出，亟需建立限水灌溉制度，实现丰产与水分高效的协调统一。于2018—2020年冬小麦生长季，选取旱地组（石麦22、衡观35和冀麦418）和水地组（石农086、冀麦585和石新828）2种类型小麦品种，设置适期播种和晚播2个播期以及春季2次灌水、不灌水和春3、4、5、6叶龄1次灌水处理。研究不同处理土壤水分动态变化及冬小麦产量形成特征。结果表明： 春季限水灌溉下，0—60 cm土层为主要供水层，其含水量（SWC60）变化显著影响小麦产量形成；春4叶龄为冬小麦春季1次灌水的最佳灌溉时期，灌水前干旱程度较轻，灌水后直至乳熟末期SWC60才低于60%，干旱胁迫也相对较轻；春季限水灌溉下，冬小麦产量显著降低，旱地组品种产量降幅低于水地组品种。不同春季叶龄1次灌水处理总体表现为春4叶龄灌水产量降幅最小，平均减产约10%。春季1次灌水晚播处理的产量水平与对应的适期播种处理无显著差异。春4叶龄灌水处理产量和水分利用效率（WUE）显著高于其他春季1次灌水处理，其单位面积穗数、穗粒数和千粒重更为均衡协调，最终在实现7 502.9~8 050.0 kg·hm^?2产量水平的同时，WUE达17.5 ~20.1 kg·hm^?2·mm^?1，较春季2次灌水节水70.1 mm。上述研究结果为构建精量高效的小麦春季限水灌溉制度提供了依据。

关键词: 冬小麦, 限水灌溉, 产量形成, 农田水分动态, 叶龄