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| DOI：10.13522/j.cnki.ggps.2021259 |
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| The Effects of Limiting Irrigation Frequency of Winter Wheat to One Time on Shallow Groundwater Balance and Wheat Yield: A Simulation Study on a Piedmont Plain of Taihang Mountain in Hebei Province |
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ZHANG Xueliang, DING Beibei
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(1. College of Land Science and Technology, China Agricultural University, Beijing 100193, China;
2. Land Engineering Technology Innovation Center, Ministry of Natural Resources, Beijing 100035, China)
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| Abstract: |
| 【Objective】Groundwater-irrigated winter wheat in the piedmont plain of Mountain Taihang in Hebei province faces a conflict between dwindled water resources and increased demand of the wheat for water. Reducing irrigation frequency of the winter wheat to just one time during its growth season is a strategy to balance groundwater conservation and wheat yield. The aim of this paper is to investigate its practicability and feasibility.【Method】We designed eight scenarios with different irrigation amounts, and simulated crop growth and groundwater variations associated with each scenario using a modified SWAT model. Based on the simulated results, a 0-1 linear programming was conducted for 22 subbasins to minimize wheat yield loss under the constraint condition of stopping the decline of shallow groundwater table.【Result】① Under the limited irrigation scheme for winter wheat with once time at the jointing stage, the declining rate of shallow groundwater table in the study area would be restrained to less than 0.34 m/a on average. However, it would reduce average wheat yield by 25%~40% in comparison with the current situation. ② Spatially, the Daqing River Dianxi Plain in the northern part of the study area had a more satisfactory groundwater conservation effects; whereas, in the Ziya River Plain, which is located at the southern part, a higher averaged wheat yield performed. ③ For most areas around Baoding, the optimized irrigation amount was 50 mm, while for areas around Xingtai and Handan, the optimized irrigation amount was 40 mm. In the southwest of Shijiazhuang, the optimized irrigation amount was 30 mm.【Conclusion】The optimized results showed that reducing irrigation frequency of winter wheat to just once at the jointing stage can achieve shallow groundwater equilibrium in approximately 70% of the study area. These results could provide quantitative reference for implementing a workable limited-irrigation scheme in this groundwater-irrigated region where the shallow groundwater has been severely overexploited for more than four decades. |
| Key words: limited irrigation scheme; shallow groundwater; groundwater equilibrium; crop yield; SWAT model; irrigation optimization |
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