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| DOI：10.13522/j.cnki.ggps.2020579 |
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| Optimizing Deficit Irrigation for Sugarcane in Guangxi Province Using the DSSAT Model |
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WANG Pengyu, LIU Jingran, ZHANG Tingqiang, LIU Xin
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1.School of Information and Electrical Engineering, Hebei University of Engineering, Handan 056038, China
2.School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering, Handan 056038, China
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| Abstract: |
| 【Background】More than 85% of sugar crops in China are sugarcane and more than 90% of its sugar is made using sugarcane. The double whammy for sugarcane production in China is the dwindling water and soil resources and the increased demand for sugar. Improving water use efficiency is hence critical to sustaining sugarcane production.【Objective】This paper is to investigate experimentally the impact of the level of deficit irrigation imposed at different stages on the growth and yield of sugarcane.【Method】The experiment was conducted at a field in Guanxi province. The crop was irrigated at seedling, tillering, elongation, and mature stage with 10 mm (T1), 20 mm (T2), 30 mm (T3) and 40 mm (T4) of water respectively, with irrigation of 50 mm taken as the control (CK). Overall, there were 17 treatments and they randomly arranged in the field. Crop growth and development in each treatment was simulated using the DSSAT model, from which we calculated the change in water productivity, irrigation water use efficiency (IWUE) and the ultimate crop yield. These results were used to optimize the deficit irrigation using the genetic algorithm.【Result】Reducing irrigation amount at seedling, tillering or mature stage improved both WUE and IWUE, although the yield difference between the treatments was not significant. Reducing irrigation amount at the elongation stage reduced the yield significantly, with T1—T4 reducing the yield by 12.33, 9.86, 5.4 and 3.53 t/hm2, respectively. The optimized deficit irrigation calculated by the genetic algorithm had the least impact on sugarcane growth, and it improved both yield and WUE as a result. Compared with CK, the optimized deficit irrigation at 30 mm and 40 mm mm increased yield by 2.5% and 8.7% respectively. Except 40 mm, all other deficit irrigations increased WUE. 【Conclusion】Considering yield and WUE, the optimized deficit irrigation calculated by the genetic algorithm was 30 mm to 40 mm at each of the four growth stages. |
| Key words: DSSAT model; sugarcane; deficit irrigation; optimization |
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