日光温室负压自动灌溉下番茄蒸腾规律研究

针对农业生产中蔬菜栽培灌溉费水费时的现状,采用一种自制负压自动灌溉系统,将供水压力设定在负值,利用土壤自动吸水的特性,达到自动灌溉和节水的效果.在此系统灌溉下采用茎热平衡技术测定番茄植株的茎流规律,分析了茎流变化规律与环境因子之间的关系,同时分析了番茄植株不同部位茎流差异以及剪叶对番茄植株茎流的影响.结果表明,在设定灌溉系统负压为60 hPa下,温室土壤含水量基本控制在阴天20.19%、晴天18.75%左右;茎流数据表明番茄植株蒸腾与太阳辐射值呈显著正相关,适当遮阴降温可以减少植株蒸腾.实验也进一步证明了叶片是植株蒸腾的主要器官,植株底层叶片蒸腾速率相对较微弱.

Research on Transpiration of Tomato under Negative Pressure Automatic Irrigation in Greenhouse

Aiming at the problem of wasting water and time in the vegetable irrigation, an automatic negative pressure irrigation system, in which the water-supply pressure was set at negative pressure and the effect of automatic irrigation and water-saving was achieved based on the characteristic of auto-water-absorbing of soil, was designed in this paper. Under the irrigation of this system, the stern-flow law of tomato plant was measured through the stem heat balance technology, the relationship between stem-flow and environment factors, the difference of stem-flow in different stem section, and the influence of leaf-cutting on stern-flow of tomato plant were analyzed. The results showed that the soil water content value was controlled at about 20. 19% in cloudy weather and 18. 75% in sunny weather when the negative pressure was set at 60hPa. The stem-flow data showed that the transpiration had significant positive correlation to the solar radiation values and proper shading could reduce the transpiration of tomato plant. The experi- ment result also further proved that leaves were the main transpiration place of the plant and the transpiration of bottom leaves of the plant was relatively weak.