Management of Al³⁺ Residue in the Soil by Mapping Soil Capability in Retaining and Transporting Al³⁺ in the Farmland of Trang Bom District, Vietnam

Abstract

The assessment of soil capability in retaining and transporting chemical substances is necessary, especially currently, with the overuse of chemical products for crop production. Depending on the soil properties, these chemicals may bound on soil particles or release and transport in the soil solution. In this study, we developed maps of the capability of soil to retain and transport Al3+, thereby evaluating the main soil factors affecting Al3+ fate in the agricultural land of Trang Bom District, Dong Nai Province, Vietnam. Information and data of the factors slope, soil texture, pH, organic matter, and ferrallitisation were processed and analyzed. The GIS tool was applied in combination with the analytical hierarchical process (AHP) to create the maps. Four hundred simulation runs were performed for criteria weight sensitivity analysis to explore the dependency of the resultant maps on the weights of the input factors. Sampling soil data were used to validate the accuracy of information given by the resultant maps. Results from the two maps show that the soils in the area have high capability in retaining and transporting Al3+. Ninety nine percent of the soils in the area have medium to high capability of Al3+ retention and about 65% of the soils have medium to high capability of transporting Al3+. For the agricultural land, about 65% of the land ranked as having a high to very high soil Al3+ retention capability and about 58% of the land ranked as having a medium to high capability of transporting Al3+. These maps can support the process of decision-making in identifying the appropriate dose and frequency of the chemical products that are applied on each soil capability zone; in this case study, the products contain aluminum. The accumulation of Al3+ in the soil, especially in the high Al3+ retention capability soil, can cause soil degradation and can cause negative effects on plant growth.

Keywords

• exchangeable aluminum
• AHP
• GIS
• soil suitability map
• soil capability map