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| DOI：10.13522/j.cnki.ggps.2019032 |
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| Experimental Study on the Effects of Different Intermittent Irrigations on Yield and Water Use Efficiency of Rice |
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WU Han, KE Jian, HE Haibing, YOU Cuicui, SHI Guangyu, WU Liquan
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1 Irrigation Experiment Central Station of Pishihang Irrigation District of Anhui Province, Lu’an 237158, China; 2 College of Agronomy, Anhui Agricultural University, Hefei 230036, China; 3 Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing 210095, China
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| Abstract: |
| 【Objective】Improving irrigation water use efficiency has become increasingly pressing for developing sustainable irrigation, and the objective of this paper is to investigate experimentally the impact of different intermittent irrigations on yield and water use efficiency of rice.【Method】The field experiment was conducted at Jianghuai region in southeast China, in which we compared two intermittent irrigations: supplemental irrigation by keeping a water layer over the soil surface for 3~5 days prior to the panicle initiation and then another 13 days after the panicle initiation (W1), supplemental irrigation by keeping a water layer over the soil surface for 7~9 days before the panicle initiation and then another 3~5 days after the panicle initiation (W2). In each treatment, we measured grain yield and water use efficiency in both 2015 and 2016; the conventional flooding irrigation served as the control (W0).【Result】The rice yield in W0 was 8.01~9.40 t/hm2, not differing significantly from that in W1 and W2. Compared to W0, W1 and W2 reduced total evapotranspiration (ET) by 3.64%~4.74% and 5.63%~8.72% respectively, with the discrepancy between W1 and W2 caused mainly by their different impact on ET in the panicle initiation and gain-filling stages. Compared with W0, W1 and W2 reduced ET by 0.66%~10.72% and 4.54%~7.33% during the panicle stage, and by 4.67%~18.47% and 20.76%~25.95% during the gain-filling stage, respectively; the reduction in ET was significant in 2016. Compared to W0, W1 and W2 saved irrigation amount by 7.50%~41.85% and 31.00%~43.94% and irrigation times by 1 and 1~2, respectively. Apart from efficacy in using precipitation, W2 was also most efficient in using irrigation water (3.79~12.66 kg/m3) and was 43.02%~98.74% and 5.59%~22.26% higher than W0 and W1, respectively.【Conclusion】Supplemental irrigation by keeping a water layer over soil surface for 7~9 days prior to the panicle initiation and then another 3~5 days after the panicle initiation can effectively reduce irrigation amount and frequency without compromising rice yield. It also improved use efficiency of both irrigation water and precipitation and is thus the optimal intermittent irrigation method for rice in Jianghuai region. |
| Key words: intermittent irrigation; intermittent time; rice yield; water use efficiency |
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