By a change in eating habits with economic development and the global population growth, we have been faced with the need for increased food production again. In order to solve the food problem in the future, the introduction of agriculture organization is progressing in emerging countries as well as developed countries. However, the occurrence of natural disasters and abnormal weather, which is becoming a worldwide problem at present, is further weakening the crops of farm products. These phenomena have been difficult to make the production of high-quality sustainably only corporate agriculture management.

 This study aims to establish an agricultural support system with advanced agricultural knowledge and technology that can support for any production area or varieties using IT. In this study, we investigated the availability of soil information collected using the soil moisture sensor (Decagon devices Inc.) to create the 3D map in the depth direction on citrus field so that making support system for precision agriculture. In addition, we developed a specification of the soil sensing device for slope field because there are many restrictions sensing of soil in the slope field.

 The research data were collected from the citrus field in Ehime prefecture (west of Osaka, Japan) . Also, citrus varieties are grown is Harehime. We set the condition that the soil information was collected 100mm away from the citrus tree, and 0mm, 200mm and 400mm below the soil surface. The number of the soil information has been collected by 138 points. This time, soil components has measured are volume water content, erectric conductivety and temperature. We created the 3D map in the direction on citrus field after the soil information with location information has been collected. Location information have been collected by using GPS receiver Hyper ll (TOPCON). The 3D maps have been created by using Arc GIS 10 (ESRI). To create the 3D maps it is adopted Kriging is a method of spatial interplation.

 After creating the 3D maps in the direction, we could obtain some considerations. First, soil information in the direction on slope field can be represented in 3D map. Moreover, it is represent the variation of the soil information. In addition, the soil information in the depth direction can be used as an index of the irrigation program. The entire conclusion reached on this study should be considered as a case study conclusion duo just one field was studied, on the other hand the approach proposed should be considered as general conclusion.