Identification of Multiple Extraction Methods to be Used in Extraction of Macro and Micronutrients of Neutral and Alkaline Soils by a Multi-Criteria Decision-Making Technique (TOPSIS)

Abstract This study aimed to determine the plant-available forms of macronutrients (P, K, Ca, Mg, S) and micronutrients (Fe, Cu, Zn, Mn, B) in neutral and alkaline soils using multiple nutrient extraction methods. It also sought to evaluate the correlations between these methods and routine soil analysis techniques through the TOPSIS multi-criteria decision-making approach. The study focused on identifying the most suitable multi-nutrient extraction method for the soils of the Thrace Region (Turkiye) and aimed to provide a methodological framework for similar research. A total of 130 neutral and alkaline soil samples from the Thrace Region were analyzed using Mehlich-3, ammonium bicarbonate-DTPA (AB-DTPA), modified Morgan (M. Morgan), acid ammonium acetate-EDTA (AAAc-EDTA), and water (W) extraction solutions, alongside routine soil analysis methods. Nutrient concentrations were determined using an ICP-OES device. Correlation coefficients between routine and multi-nutrient extraction methods were calculated, and the TOPSIS technique was applied to rank the extraction methods based on these coefficients. The TOPSIS analysis ranked the multi-nutrient extraction methods for neutral and alkaline soils of the Thrace Region as follows: 1) AB-DTPA, 2) Mehlich-3, 3) AAAc-EDTA, 4) M. Morgan, and 5) Water. The AB-DTPA and Mehlich-3 methods were identified as the most effective multi-nutrient extraction methods for neutral and alkaline soils in the Thrace Region. These methods are recommended for practical use, with their limitations in correlation relationships and analytical precision noted. Further studies are required to address these limitations and enhance the reliability of these methods in diverse soil analysis applications.