水稻茎秆对稻田净灌水量测量值的影响

为快速准确测算稻田净灌水量,采取小区试验与大田同步验证的方法,分析直接量测与观测分析2种方法所得小区净灌水量间的差异及原因,并引入偏差系数K(即用2种方法测量值的比值表示直接量测法的偏差程度)。结果表明:水稻茎秆对田面水层的填充作用,会对直接量测法所测净灌水量产生影响;与观测分析法相比,直接量测法所测稻田单次净灌水量偏大1.4%~11.7%,且此偏差在水稻生育初期较小,至生育末期逐渐增加至最大;茎面积指数SAI与K成明显线性关系,采用SAI对直接量测法所测结果进行校准,可减少稻田总净灌水量测算偏差2.3%~6.3%。

Influence of Rice Stalks on the Net Irrigation Water Volume Measurement in Paddy Field

In order to improve the efficiency and the accuracy of the measurement of the net irrigation water volume in the paddy field, a plot experiment and a field experiment were taken and two methods,direct measurement method and observation-analysis method, were used in the experiments.The difference between the two methods were compared and analyzed,and the deviation coefficient K, the ratio of the two methods of measuring value,was introduced to indicate the deviation degree.The results showed that rice stalks might fill the field water layer and so affect the direct measurement value.The single net irrigation water volume values measured by direct measurement method were 1 .4%~1 1 .7% higher than those measured by observation-analysis method.Moreover,the devia-tion was small in the early stage of rice growth,and gradually increased to the maximum at the late growth stage.The stem area in-dex (SAI,ratio of the total submerged plant stem areas and the total land areas)and K had a good linear relationship,and SAI was proposed to modify the value of direct measurement,and the deviation could be reduced by 2.3%~6.3%.