β射线探测器可用来测定植物叶片的水份含量。关于该仪器应用于植物科学研究的优缺点,已经有人评论过。这种仪器可以连续地、非破坏地测定植物活体叶片内部的水份变化。试验已经证明;用β吸收法测量土壤表面露水的精度比用其它常规的露水计测量方法要高。但β射线探测器在农业研究的其它方面的应用尚未探讨。本论文研究应用β射线探测器研究半干旱农业区的大田植物-水份关系。 Beta ray detector can be used to determine the moisture content of plant leaves. The advantages and disadvantages of this instrument used in plant science research have been commented on. This instrument allows continuous, non-destructive determination of changes in the water inside plant living leaves. Experiments have shown that the accuracy of soil dew measurement using the beta-absorption method is higher than with other conventional dew-point measurement methods. However, the application of β-ray detectors in other aspects of agricultural research has not yet been explored. In this thesis, β-ray detector was used to study the field-plant-water relationship in the semi-arid agricultural area.