Abstract
The radiation transfer model of Ross, J. was applied to the radiation field in the plant canopies of spring wheat and field beans. The calculation was compared with the experimental data of Szeicz. The estimated values were utilized by way of compensation for the deficit of the data of Szeicz. The reflectances of ground were omitted because of large LAI values. The reflectances of leaf were estimated from the data of Gausmann. The leaf normal distribution function and the PAR conversion factor were adopted as parameter. The PAR conversion factor was insensitive to the results. If the leaf normal distribution function was a uniform or erectophile type, the results compared favorably with the experimental data. The compared item is the normalized downward radiant flux density. The results were in accordance with the experiment. The validity of Ross'es model was verified by the present study.
