Application of Neutron Radiography to the Study of Water Behavior in Soil

Abstract

Neutron radiography (NR) was applied to study water behavior in soil, non-destructively. Using Toyoura sand as standard, the image of water was correlated well with the water content by chromatogram scanner. The image of water absorbing polymer was also analyzed by NR. As the water content becomes higher, the polymer size and water content comes higher, which was clearly shown by the radiogram. The size of the polymer swelled with water was analyzed by the image scanner and was shown to be related well with the water content. The calibration curves of absorbance with the water content of sand alone and the sand with the polymer indicated that water behavior in the sand could be analyzed quantitatively as well as visually by NR. When the plant was grown in the sand, the image of root and water could be observed in the radiogram. Therefore, the NR was shown to be a useful method for the non-destructive study of water behavior in soil around root.