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| DOI：10.13522/j.cnki.ggps.2025308 |
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| Effects of irrigation water sources on root-zone water and salinity dynamics and maize water use efficiency |
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ZHAO Zibo, DU Xiangbing, LI Wangcheng, JIA Zhenjiang, AN Wenju, LYU Hang, LI Xu, HE Lei
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1. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China;
2. Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions,
Ministry of Education, Yinchuan 750021, China; 3. Ningxia Hui Autonomous Region Key Laboratory of
Yellow River Water Network Digital Water Control, Yinchuan 750021, China
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| Abstract: |
| 【Objective】Water scarcity is a major challenge for sustainable agriculture in the arid Yinbei Irrigation District of Ningxia. To address this, various water resources, including Yellow River water, shallow brackish groundwater, and agricultural return flow, have been explored for irrigation. This study investigates the effects of these irrigation water sources on root-zone water and salt dynamics and their consequences for maize growth.【Method】The experiment was conducted in a maize field from April to August 2024 in Tonggui, Xingqing District, Yinchuan City. It included three irrigation water types: diverted Yellow River water (S1), agricultural return flow (S2), and shallow groundwater (S3), combined with two irrigation quotas: 330 mm (I1) and 190 mm (I2). The control (CK) used Yellow River water with an irrigation quota of 412 mm. During the experiment, soil water content and salt concentration in the root zone and maize growth traits were measured.【Result】①When the irrigation quota was 330 mm (I1), S3 reduced soil water content in the 0-40 cm layer by 25.49% and 15.69%, and soil electrical conductivity by 61.15% and 38.22%, compared with S1 and S2, respectively. ②When the irrigation quota was 190 mm (I2), salts were more likely to accumulate in the 20-60 cm root zone, with salt accumulation increasing with the salinity of the irrigation water. Under S3, increasing the irrigation quota enhanced salt leaching from the 0-40 cm layer to the 40-80 cm layer. ③Under the low irrigation quota (I2), S3 and S2 increased grain yield by 10.12%-14.44% and improved water use efficiency (WUE) by 28.08%-37.33% compared with the high irrigation quota (I1). Compared to CK, S3I2 and S2I2 increased grain yield by 0.56% and 11.97%, and WUE by 48.14% and 54.17%, respectively. ④Path analysis indicated that irrigation quota was the primary factor affecting yield and WUE, while water quality played a key role through its influence on root zone salinity.【Conclusion】In areas with shallow groundwater, applying a reduced irrigation quota (190 mm) using agricultural return flow or shallow brackish groundwater during the critical water demand stage of maize can save freshwater resources without reducing grain yield. |
| Key words: brackish water use; irrigation water quality; salt accumulation; water use efficiency; shallow groundwater |
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