| 引用本文: | 张宝珠,王仰仁,李金玉, 等..基于称重式蒸渗仪的春玉米蒸散量研究[J].灌溉排水学报,2021,(11):17-25. |
| ZHANG Baozhu,WANG Yangren,LI Jinyu, et al..基于称重式蒸渗仪的春玉米蒸散量研究[J].灌溉排水学报,2021,(11):17-25. |
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| 摘要: |
| 【目的】分析春玉米蒸散变化规律及建立产量与水分的关系，为山西省春玉米灌溉需水量的精准调控提供依据。【方法】利用山西省中心灌溉试验站称重式蒸渗仪在2019—2020年春玉米不同供水量条件下的蒸散发测定试验，共设置4个处理，分别为T1（5水）、T2（6水）、T3（4水）、T4处理（2水），按照作物需水量确定灌水时间，灌水定额均为60 mm，每个处理配置1套称重式蒸渗仪，自动记录逐时土体水质量。利用水量平衡方法计算逐日蒸散量，分析蒸散变化规律，并利用相对腾发量为自变量的过程模型，建立产量与蒸散量之间的关系。【结果】发育中期日蒸散强度较其他生育阶段蒸散强度大，受灌水的影响，灌溉定额越大，不同生育阶段的日蒸散强度普遍增大，T2处理发育中期，13:00蒸散量最大为0.44 mm/h，T4处理发育中期09:00蒸散量最大为0.175 mm/h；灌水也会影响灌后几日蒸散量，灌水越多，蒸散量也越多，累计蒸散量也越大。春玉米生育期内蒸散作用主要集中在发育中期（播后的52~120 d），该时期日最大蒸散量，2019年和2020年分别为10.68 mm/d和7.27 mm/d，相应的蒸散量占全生育期蒸散量比例分别为75.7%和72.9%。以相对腾发量为自变量的过程模型对产量进行了模拟，率定了模型参数，拟合效果很好，相关系数（R2）达到0.99以上，并利用文峪河2018—2020年春玉米的测试资料进行模型参数验证，R2达到0.94以上，表明率定的参数合理。【结论】基于蒸渗仪测定数据能更准确地确定产量与水分关系，此外，利用FAO推荐的作物系数法计算的蒸散量很好地反映了作物的潜在蒸散量。 |
| 关键词: 蒸渗仪；蒸散量；水量平衡；产量；相对腾发量 |
| DOI：10.13522/j.cnki.ggps.2021062 |
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| Evapotranspiration from Maize Studied Using Weighing Lysimeters |
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ZHANG Baozhu, WANG Yangren, LI Jinyu, et al.
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1. School of Hydraulic Engineering, Tianjin Agricultural University, Tianjin 300392, China;
2. Shanxi Central Irrigation Test Station, Wenshui 032107, China
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| Abstract: |
| 【Objective】Evapotranspiration is important not only as a component of the hydrological cycle but also for its role in modulating crop growth. The purpose of this paper is to measure the evapotranspiration of spring maize using weighing lysimeters and analyze its relationship with the yield and water use efficiency of the crop.【Method】A two-year experiment was conducted in Shanxi province from 2019 to 2020, and the evapotranspiration of spring maize under different water supplies was measured using weighing lysimeters. We compared four irrigation schedules: irrigating 5 times (T1), 6 times (T2), 4 times (T3) and 2 times (T4), with irrigation amount in all them being kept at 60cm. The irrigations differed only in the criteria set to resume irrigation, judged by a critical soil moisture measured in situ. Hourly changes in soil water content in all lysimeters were recorded automatically, and daily evapotranspiration was calculated using the water balance method, from which we further analyzed the relationship between yield and evapotranspiration.【Result】The evapotranspiration rate peaked in the middle of growing season in all treatments, and the daily evapotranspiration rate in all growing stages increased with the irrigation amount. In T2, the maximum evapotranspiration rate was 0.44 mm/h occurring at 13:00 pm, while in T4 it was reduced to 0.175 mm/h occurring at 09:00 am. The legacy of the effect of irrigation scheduling on evapotranspiration lasted a few days following the irrigation. The more frequently the crop was irrigation, the more the water would be evaporated or transpired. Most soil water was lost via evapotranspiration in the middle growth stage, i.e., 52 to 120 days after drilling the seeds; the maximum daily evapotranspiration during this period was 10.68 mm/d in 2019 and 7.27 mm/d in 2020, accounting for 75.7% and 72.9% of the total evapotranspiration in each of the two years, respectively. Model using relative evapotranspiration to predict the crop yield gave a good fitting with a correlation coefficient R2 > 0.99. Further verification of the model against data measured from 2018 to 2020 from a spring maize field in Wenyu River Basin proved the robustness of the model with a correlation coefficient R2 >0.94.【Conclusion】Evapotranspiration measured from the weighting lysimeter was accurate and can be used to predict yield and estimate soil water change. |
| Key words: Weighting lysimeter; evapotranspiration; water balance; corn yield; relative evapotranspiration |
