模拟酸雨对荔枝园土壤氮素迁移和土壤酸化的影响

Effects of Simulated Acid Rain on Nitrogen Transplant and Acidifying Potential in Litchi Orchard Soils

采用短期室内淋溶方法研究了模拟酸雨对供试荔枝果园土壤全N、碱解N、硝态N、铵态N含量变化的影响。结果表明,各处理土壤淋出液的全N、硝态N、铵态N含量随着模拟酸雨酸度的增强而依次增加,其中pH 2.5酸雨淋溶处理与其它处理间的淋出液含量差异显著,而pH≥4.5酸雨淋溶处理与对照(pH 6.5)间的差异大部分不显著;各处理的土壤较淋溶前其全N、NO3-_N(pH 2.5酸雨处理例外)、NH4+-N的含量均有增加趋势。引进土壤的实际酸化速率H+产生值衡量供试土壤的酸化,只有pH 2.5的模拟酸雨淋溶促进了土壤的酸化,而pH≥3.5的模拟酸雨处理对土壤的酸化具有一定的缓冲作用,且土壤酸度减弱。

Through short-term indoor leaching, the effects of simulated acid rain on total soil nitrogen, alkaline hydrolysable nitrogen, nitrate nitrogen, ammonium nitrogen contents in litchi orchard under consideration were studied. It was shown that TN, NO3^--N, NH4^＋-N concentrations in leachates increased with the increment of pH of the simulated acid rain, and significant differences between pH 2.5 and the other pH treatments were found, but there were no significant difference between pH 4. 5 （or 5.5） and CK （pH6.5）. As for soil after leaching, TN, NO3^--N（except pH2.5）, NH＋--N contents had trend to be increased compared with those before leaching. Introduce of actual acidification velocity（H＋ produced） for evaluating the acidifying effects of soil tested, only the stimulated acid rain with pH2.5 could lead to soil acidifying, however, acid rains with pH≥3.5 played a buffering role to soils tested, with the weakening of soil acidity .