College of Agronomy, Shandong Agricultural University, State Key Laboratory of Crop Biology, Key Laboratory of Crop Ecophysiology and Farming System, Ministry of Agriculture, Taian, Shandong, People's Republic of China.
Zibo HeFeng Seed Technology co., ltd., Linzi, Zibo, Shandong, People's Republic of China.
PLoS One. 2020 Apr 7;15(4):e0230484. doi: 10.1371/journal.pone.0230484. eCollection 2020.
To solve the problems of yield reduction and low water-use efficiency (WUE) of winter wheat (Triticum aestivum L.) caused by winter and spring drought, a 2-year field experiment (2017-2019) was performed under movable shelter conditions with the large- and multispike cultivars Shannong 23 and 29, respectively, to explore the optimal supplemental irrigation regime. Three wetting layers were used for irrigation at the jointing stage: 0-10 cm (T2), 0-20 cm (T3) and 0-30 cm (T4). No irrigation at the jointing stage (T1) served as the control. Within a given cultivar, the soil water content in the 0-80 cm soil layers increased after irrigation, and the rate of tiller mortality decreased with increasing depth of the wetting layer used for irrigation at jointing. No significant differences were found between the T3 and T4 treatments in the photosynthetic rate (Pn) of the apical leaf of the main stem (O), the first primary tiller (I) and the fourth tiller (IV) after jointing. However, compared with the T3 treatment, the T4 treatment had a significantly higher transpiration rate (Tr) and lower instantaneous water-use efficiency (WUEleaf) of the apical leaf of the O and tillers I and IV. This eventually led to a decreasing WUE, although there was no significant change in the spike number or grain yield. These results indicated that moderate irrigation at jointing can effectively reduce the tiller mortality, improve the leaf Pn of the tillers, and increase the spike number and grain yield. However, excessive irrigation can significantly increase the leaf Tr of the tillers, lead to inefficient water consumption and significantly reduce the WUEleaf of the tillers and the WUE. Irrigation at the jointing stage brought the soil water content in the 0-20 cm profile to 100% of field capacity, making it the most suitable supplemental irrigation regime for both the large- and multispike cultivars in the North China Plain.
为解决冬小麦冬春干旱导致的减产和水分利用效率（WUE）低的问题，2017-2019 年采用移动遮雨棚设置田间试验，以多穗型品种山农 29 和大穗型品种山农 23 为材料，研究不同灌水处理对冬小麦旗叶及不同位蘖光合特性和产量的影响。在起身期设置 3 个不同的湿润层：0-10 cm（T2）、0-20 cm（T3）和 0-30 cm（T4），T1 为不灌水处理。结果表明：在同一品种条件下，灌水处理后 0-80 cm 土层土壤含水量增加，且随灌水处理湿润层加深，分蘖死亡率降低。T3 和 T4 处理间主茎倒二叶（O）、第一分蘖（I）和第四分蘖（IV）的光合速率（Pn）差异不显著，但 T4 处理的蒸腾速率（Tr）显著高于 T3 处理，O 和 I、IV 叶片的瞬时水分利用效率（WUEleaf）显著低于 T3 处理，最终导致 WUE 降低，但穗数和产量无显著变化。说明起身期适度灌溉能有效降低分蘖死亡率，提高分蘖叶片的光合能力，增加穗数和产量；过量灌溉则会显著提高分蘖叶片的 Tr，导致水分利用效率降低，显著降低分蘖的 WUEleaf 和 WUE。灌水处理将 0-20 cm 土层土壤含水量提高至田间持水量的 100%，是适宜于华北平原大穗和多穗型品种的灌水处理方式。
