通过实验探讨了植物的激光诱导叶绿素荧光光谱与土壤水分间的关系。 实验利用Y-形光纤探头获取了植物在450 nm LED光源照射下所发出的叶绿素荧光光谱, 同时利用TDR传感器测量土壤湿度。 实验以水稻为研究对象, 研究了在持续水分胁迫和间歇水分胁迫下, 叶绿素荧光光谱743 nm附近波峰的变化, 结果发现, 波峰强度与土壤水分含量具有相关性。 最后, 利用Lorentzian方程, 将持续水分胁迫下的土壤含水量与叶绿素荧光强度进行建模, 发现所建的模型具有较高的决定系数, 说明该方法可以应用于农业生产中对土壤水分的测量。

Online measurement of soil moisture is significant for agricultural production. The abundance and deficiency of leaf water shortage has been able to effect measured by fluorescence, but the research of correlation between soil moisture and laser-induced fluorescence spectroscopy has not been carried out yet. In this paper, the relationship between laser-induced plant chlorophyll fluorescence and soil moisture was studied. In the experiment with rice as the research object, the chlorophyll fluorescence induced by a 450 nm LED light source was measured by a Y-shaped fiber probe, and the soil moisture was obtained by TDR sensors. The changes in the peak intensity near 743 nm of chlorophyll fluorescence under continuous water stress and intermittent water stress were studied. The result showed that the intensity decreased with the soil moisture content. Finally, the model between the soil water content and the intensity of chlorophyll fluorescence under continuous water stress was created by using Lorentzian equation, and the coefficient of determination (R2) of the model was high. The result indicated that the method mentioned in paper can be applied to measure soil moisture in agricultural production.