Abstract
A soil database has been created based on soil maps (soil map database) and soil survey information (soil information database) using a general purpose geographical information system and database software on a personal computer, and examples of application of this database are introduced. 1. In the soil map database, a polygon showing boundaries of agricultural land is distinguished by soil division authorized by the prefecture concerned. Soil classification information, and the latest information on physical and chemical characteristics of plowed soil obtained from a survey made at about 550 points are used as information for its attributes. 2. Drawing of a soil map such as a CEC distribution diagram that is based on the polygon attributes information, and area aggregation are made easy after the soil map information is integrated into a geographical information system. 3. Photographs showing section, geologic column and compactness distribution diagram are integrated into the soil information database together with characteristics of the soil, and physical and chemical characteristics information for plowed soil and next layer soil to allow a visual understanding of soil condition down to the substratum (about 80 cm deep). 4. After the soil map and soil information database are converted into image data, a cultivated field soil information database is created by HTML. It is now possible to retrieve soil distribution and current soil condition with ease.
