Organic Matter Leached from Tropical Soils by Simulated Rain, Hard (NaOH) and Soft (NaNO3) Extractions: A Realistic Study about Risk Assessment in Soils

Alkaline extractions from humic material are used to risk assessment in soils. However, there are questions about the type of extraction most suitable for this evaluation. Thus, this work evaluated different soil extractions in search of realistic environmental conditions (simulated rain). The parameters obtained revealed significant differences between the levels and structural characteristics of organic matter, depending on the extractant used, reinforcing the importance of developing methodologies and analytical procedures that minimize structural changes and may be more representative of the molecular structures of organic matter found in soils. The results showed that the material extracted by simulated rain is similar to the fulvic acids of the soil organic matter extracted by alkaline extraction showing the importance of this type of extraction for risk assessment studies in soils.