| Abstrakt: |
Effects of acid rain in soils have received less research attention when compared with other environmental issues. Understanding and simulating the long-term effects of acid rain on the leaching of cations from calcareous soils are essential. Therefore, this study was carried out to determine the effect of simulated acid rain on the cations leaching in a calcareous sandy loam soil at various pH levels of 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, and 7.0. Results showed that the leaching of cations depended on soil pH. After 40 days of leaching, calcium (Ca2+) and magnesium (Mg2+) losses were 361.8 to 116.5, and 156.1 to 64.9 mg kg−1, at pH treatments of 2.5 and 7.0, respectively, while potassium (K+) losses from soil at pH 2.5 and 7.0 were 31.8 and 17.5 mg kg−1, respectively. The amount of sodium (Na+) losses was lower than other cations. A nonlinear correlation was found between the cumulative amounts of cations leached and pH. Additionally, PHREEQC was used to simulate the transport of cations and experimental data sets agree well with the model predictions. Based on this study, the observed concentrations of base cations in the leachates result from the dissolution of soil minerals, such as calcite, dolomite, gypsum, halite, sylvite, and cation exchange in soils. The findings suggested that, in the long-term, acidic inputs would increase cation losses from calcareous soils, potentially leading to plant deficiencies and groundwater quality degradation. [ABSTRACT FROM AUTHOR] |
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