| Cite this article: | 李银坤,詹保成.基于蒸发皿蒸发量的温室生菜适宜灌溉量研究[J].灌溉排水学报,2022,():-. |
| liyinkun,zhanbaocheng.基于蒸发皿蒸发量的温室生菜适宜灌溉量研究[J].灌溉排水学报,2022,():-. |
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| DOI： |
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| Study on Appropriate Irrigation Amount of Greenhouse Lettuce Based on Pan Evaporation |
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liyinkun, zhanbaocheng
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Intelligent Equipment Research Center, Beijing Academy of Agriculture and Forestry Sciences
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| Abstract: |
| 【Objective】 The aim of this paper is to study the rational irrigation strategy of greenhouse lettuce based on pan evaporation (Ep). 【Methods】 Five irrigation treatments were applied in greenhouse: 0.3Ep(I1), 0.5Ep(I2), 0.7Ep(I3), 0.9Ep(I4) and 1.1Ep(I5). Water evaporation (Ep) of canopy was automatically recorded by weighing standard evaporation pan with a diameter of 20 cm, and two consecutive greenhouse lettuce experiments were carried out. The effects of different irrigation treatments on evapotranspiration, aboveground biomass, yield and water use efficiency of greenhouse lettuce were studied, and then the appropriate irrigation amount and its corresponding pan irrigation coefficient (Kp) of greenhouse lettuce were determined. 【Results】 During the experiment, Ep showed a rising trend with the increase of time, and the cumulative Ep of the second crop was 96.0 mm, which increased 33.4% compared with the first crop. Solar radiation was an important environmental factor affecting Ep, and there was a significant positive correlation between them (P<0.01). The cumulative evapotranspiration of lettuce under different treatments in the first and second stubble varied from 43.4 mm to 70.4 mm and 58.3 to 73.6 mm, respectively, and increased with the irrigation amount increasing. For the treatments I1, I2 and I5 in the second stubble, the cumulative evapotranspiration were 58.3 mm, 67.0 mm and 73.6 mm, respectively. With the increase of irrigation amount, the aboveground biomass of lettuce in greenhouse increased firstly and then decreased. Compared with the treatments I1 and I5, the aboveground biomass of treatment I3 was the highest, which was increased by 17.5%~38.2% and 4.2%~13.2%, respectively. The yield and water use efficiency of lettuce in greenhouse were significantly improved through proper irrigation. Compared with treatments I1 and I5, the yield of lettuce in treatment I3 increased by 36.6%~37.3% and 6.1%~23.7%, water use efficiency increased by 9.9%~15.2% and 12.6%~61.4%, respectively. There was a quadratic relationship between lettuce yield and pan irrigation coefficient (Kp) (P<0.01). When Kp of two crops was 0.77, the highest yield was obtained. 【Conclusion】 The experimental results indicated that the treatment I3 (0.7Ep) was the suitable irrigation amount for greenhouse lettuce under experimental conditions. In order to obtain high yield of greenhouse lettuce, the optimal pan irrigation coefficient is recommended to be 0.77. |
| Key words: greenhouse lettuce; weighing lysimeter; water surface evaporation; yield; water use efficiency |
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