Abstract
The remote sensing technique can provide much useful informatin to pedological research, especially in the area of soil mapping. In this report two experiments have been described. The model experiment was for differentiating between wet and dry soil using infrared radiation, the second experiment was carried out in which paddy soils were classified by density slicing of thermal mapper photographs. The model experiment was performed on November 29th 1974 in the lysimater of the National Institute of Agricultural Sciences, Tokyo. The variations of surface soil temperature under optimum weather conditions (i. e. sunny, no wind) for one day period were measured. Three types of soils (Volcanic ash soil, Alluvial soil and Sandy soil) were used and the ground water levels were carefully controlled. The results are listed as follows. 1) The maximum surface soil temperature difference between wet and dry soil occurred at noon. 2) In sandy soil the greatest temperature difference (about 7℃) was recorded. 3) The surface soil temperature was greatly influenced by the density of plant life. The thermal mapper photographs were taken twice (at nine A.M. and noon) on November 27th 1974 in the northern part of Hiratsuka, Kanagawa Prefecture. In the photographs which were taken at noon, a clear contrast in paddy field area could be recognized, on the other hand in the photographs which were taken at nine A.M., this contrast could not be recognized. Strong gley soil, gley soil and gray lowland soil in this area was classified by density slicing of the photographs which were taken at noon.
