Topsoil physicochemical properties: A case study in the buffer zone of Tram Chim National Park , Tam Nong district , Dong Thap province, due to the impact of climate change

Abstract

Climate change has a significant impact on soil physicochemical properties due to elevated temperatures and changes in precipitation patterns. The physical and chemical analysis of six topsoil types in t he buffer zone of Tram Chim National Park indicated that the soil texture is primarily clay, with percentages greater than 40%, bulk density ranges from 0.62 to 1.18 (g/cm 3 ), followed by silt (28.50 - 37.90%) and sand (19.40 - 28.93%). There is no significant difference in the pH of all topsoil types, which ranges from acidic to slightly acidic (pH KCl : 3.81 – 4.78). The cation - exchange capacity (CEC) of the soil is medium to high (17.88 - 27.83 meq/100g of soil) and nutrients including organic matte rs (OM) and total nitrogen (N), are rich to very rich (OM: 4.24 - 19.05%; N: 0.21 - 0.37%). These topsoil types are good at adsorbing plant nutrient cations. However, total potassium (K 2 0) and total phosphorus (P 2 0 5 ) are low, and total sulfur (SO 4 2 - ) is at low - medium levels (approximately 0.042 - 0.08%), which is toxic and harmful to plants. Total soluble salts (TSS) of all samples are at a very low level (< 0.16%). In contrast, for Gleyic Acrisols (Xf), the percentage of sand is the highest, and clay is th e lowest. Its cation - exchange capacity and nutrients are almost lower than those of the analyzed topsoil samples in the study. With increasing temperature, drought, and decreasing rainfall in both amount and frequency, the topsoil layer is more frequently exposed to high surface temperatures, leading to heavy acidification, nutrient reduction, and soil degradation.