| 摘要: |
| 【目的】探究基于蒸发皿水面蒸发量（Ep）的温室生菜适宜灌溉策略。【方法】设置5个灌溉处理：0.3Ep（I1）、0.5Ep（I2）、0.7Ep（I3）、0.9Ep（I4）和1.1Ep（I5），利用直径20 cm的称重式标准蒸发皿自动记录冠层水面蒸发量（Ep），开展了连续两茬温室生菜灌溉试验。通过研究不同灌溉处理对温室生菜蒸散量、地上部生物量、产量和水分利用效率的影响，确定温室生菜适宜的灌溉量及其对应的蒸发皿适宜灌溉系数（Kp）。【结果】试验期间，Ep随时间的增加呈上升趋势，第二茬累积水面蒸发量为96.0 mm，相比第一茬增加了33.3%；太阳辐射是影响Ep的重要环境因子，二者呈显著正相关（P<0.01）。第一茬和第二茬各处理的累积蒸散量波动范围分别为43.4~70.4 mm和58.3~73.6 mm，累积蒸散量随灌水量的增加而增加。生菜地上部生物量随灌溉量的增加呈先增加后降低的变化规律，其中I3处理地上部生物量最高，相比I1处理和I5处理分别提高了17.5%~38.2%和4.2%~13.2%。适量灌溉可显著提高温室生菜的产量和水分利用效率，与I1处理和I5处理相比，I3处理的产量增加了36.6%~37.3%和6.1%~23.7%，水分利用效率提高了9.9%~15.2%和12.6%~61.4%。生菜产量和蒸发皿灌溉系数（Kp）之间具有显著的二次曲线关系（P<0.01），综合两茬产量，当Kp为0.77时可获得生菜产量的最高值。【结论】I3处理（即0.7Ep）是供试条件下温室生菜的适宜灌溉处理，在以获得温室生菜高产为目标时，推荐蒸发皿灌溉系数取0.77。 |
| 关键词: 温室生菜；称重式蒸渗仪；水面蒸发量；产量；水分利用效率 |
| DOI： |
| 分类号:S274.3; S626.5 |
| 基金项目:国家重点研发计划资助(2020YFD1000300), 河北省重点研发计划项目（21327005D） |
|
| Study on Appropriate Irrigation Amount of Greenhouse Lettuce Based on Pan Evaporation |
|
liyinkun, zhanbaocheng
|
|
Intelligent Equipment Research Center, Beijing Academy of Agriculture and Forestry Sciences
|
| 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 |
