本实验采用在水中加入化学示踪剂钾离子的方法探讨低压固定式喷灌时的蒸发损失。钾离子浓度通过监测地面容器中的集水和距连续供水管(模拟灌机)60m下风处的大气得到使用光滑折射板喷头时,蒸发幅度为0.5～1.4％;使用粗齿喷头时,蒸发幅度为0.4～0.6％。使用光板喷头所测得的蒸发量同Kinzer和Gunn,1951年的计算结果高度相关(R~2=0.98)。 In this experiment, the method of adding potassium as a chemical tracer to water was used to investigate the evaporation loss under low pressure fixed sprinkler irrigation. Potassium ion concentration The evaporation amplitude is 0.5-1.4% with the use of a smooth refraction plate nozzle by monitoring the water catchment in the surface container and the air at 60 m downwind from the continuous water supply pipe (analog irrigation); when the coarse tooth nozzle is used, the evaporation amplitude 0.4 ~ 0.6%. The evaporation measured using a plate spray nozzle is highly correlated with the calculated results of Kinzer and Gunn in 1951 (R ~ 2 = 0.98).