SOIL TRACE-ELEMENTS AVAILABILITY MAPS OF HUNGARY

The trace-element status of soil can be a measure for soil fertility a nd, at the same time, it is an indicator of possible environmental haz ard in the case of excess values. Large numbers of soil samples have b een analyzed for five trace elements (B, Cu, Mn, Mo, Zn), considered t he most important for plant production. Availability indexes were calc ulated using analytical data in combination with other properties of t he soil. Evaluation of the results was based on field experiments and the trace-element contents of plants. The unevenly distributed point d ata were processed with GIS software. The work was carried out within a COST project. The basic data capture was made with Arc/Info. For the rest of the work, after proper data conversion, IDRISI was used. Some missing data were calculated by multiple regression based on the samp ling of images for soil properties correlated with the trace-elements availability-index numbers. Then, the built-in geostatistical function s were used to convert the point data into raster map images. The clas sified images proved that nearly half the territory has a low value fo r Zn and one third is high in Mn. These data indicate the possible def iciency or toxicity occurrences and their locations in the country. Th e work leading to this paper contains the necessary steps for data pro cessing, the classified maps of soil trace-elements availability-index values, reveals the problems and shows the use of GIS application for agricultural and environmental management purposes.