The use of computer assisted tomography to determine spatial distribution of soil water content

Abstract

To date no experimental technique has been capable of directly and repetitively measuring spatial distributions of soil water content in a non-destructive manner. The potential of computer assisted tomography (CAT) to overcome this problem has been examined in this paper. The results obtained from a commercially-produced X-ray CAT scanner and a conventional gamma scanner suggest that CAT scanning can be used to determine spatial changes in soil water content with adequate resolution for soil-plant studies. The technique can clearly be used to resolve spatial changes in soil water content with time. Application of the technique to water uptake by a single plant root shows that CAT scanning presents an extremely exciting possibility for studies of soil-plant water relations.