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| DOI：10.13522/j.cnki.ggps.2019008 |
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| Response of Rice Water Requirement to Groundwater Depths and Irrigations Simulation in Cold Region of Northeast China |
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TIAN Yini, SHAO Dongguo, LI Siming, WANG Bai
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1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China;2. Heilongjiang Province Hydraulic Research Institute, Harbin 100050, China
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| Abstract: |
| 【Objective】The objective of this paper is to reveal the response rules of rice water requirement to groundwater depth changes and irrigations in cold region of northeast China under different precipitation years, and to further optimize the rice irrigation schedules.【Method】Based on years of rice irrigation experiments and groundwater dynamic observation data in 2017 at the irrigation experiment station of Qing’an Heping Irrigation District of Heilongjiang Province, the rice water consumption and groundwater dynamics under different irrigation patterns were analyzed. The applicability of AquaCrop model in rice growth simulation in cold region of northeast China was verified, and it was used to simulate and analyze the relationship between rice water requirement and different groundwater depths and the response rules of irrigations under three types of precipitation years of 25%, 50% and 75%. The groundwater depth range and the net irrigation amount in the growth period suitable for high yield of rice in this region were proposed.【Result】①The groundwater depth in the rice growth period was shallow first and then deep, the water consumption in tillering stage, booting stage and earing stage were large, rainfall and irrigation amount were large, and the depth of groundwater was shallow. ②The multiple regression equations of ET, GD and I under three types of precipitation years were established, and the correlation between rice water requirement, groundwater depth and irrigation amount in growth period were comprehensively considered, which could be used for efficient water consumption management of rice fields and sustainable utilization of groundwater resources. ③In order to achieve the double goal of high yield of rice and basic stability of groundwater depth in cold regions of Northeast China, the groundwater depth should be controlled between 2.0 and 2.5 m. In dry year, the net irrigation amount during the rice growth period should not be lower than the current irrigation amount, namely 300 mm. But in wet year and normal year, it could be appropriately reduced to 0.8 times of the current irrigation amount, namely 240 mm.【Conclusion】The range of groundwater depth and the amount of net irrigation during the rice growth period proposed in this paper can provide a theoretical basis for promoting water saving and grain increase in northeast China, protecting wetland ecological environment and improving agricultural water use efficiency. |
| Key words: cold region; rice water requirement; groundwater depth; irrigation amount; AquaCrop model; water productivity |
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