第四纪红粘土发育的红壤在施用石灰和石膏后元素的淋溶特征

本文利用模拟土柱试验研究了施用石灰和石膏对第四纪红粘土发育的红壤中元素淋溶过程的影响。结果表明，施用石灰后１０ｃｍ土层中除Ｃａ＾２＋以外的阳离子元素的淋失量减少，而ＳＯ４＾２－和ＨＣＯ３＾－的淋失量增加；施用石膏后１０ｃｍ土层中所有阳离子元素，特别是ＡＩ＾３＋的淋失量增加。红壤中Ｃａ＾２＋的淋失以自由态为主，施用石膏后与ＳＯ４＾２－结合的比例增加，不同处理中３０ｃｍ土层处铝的淋失以自由态为离，１０

CHARACTERISTICS OF ELEMENT LEACHING OF RED SOIL DERIVED FROM QUATERNARY RED CLAY SUPPLIED WITH LIME AND GYPSUM

The effect of applying lime and gypsum on element leaching in red soil derived from Quaternary red clay was studied with soil columns repacked in laboratory.Results showed that lime application decreased the leaching from the short columns (0-10cm layer) of canons exclude Ca²⁺,but increased the leaching of SO₄^2- and HCO₃^-.Supplying gypsum increased the leaching, from topsoil column of all cations,especially of Al³⁺,but has no effect on the leaching of HCO₃.Ca²⁺ leached mainly in the form of free ion, and the percentage of SO bound Ca²⁺ rose when adding gypsum. For the leaching of A1³⁺ from the long column(0-30 cm layer), it was mainly in the form of free ion.For the leaching of Al>³⁺ from the topsoil column, it was mainly in the form of OH^- bound Al>³⁺ in lime treated soil;however,the main form was SO₄^2- bound Al in the early stage and free ion in the later stage in gypsum treated soil. Besides that the percentage of OH^- bound Al>³⁺ enhanced in the topsoil solution in all lime-addition soils, that of SO₄^2- bound Al>³⁺ increased in all subsoil solution and in topsoil solution in gypsum treated soils.