江苏滨海盐土与花碱土脱盐过程中盐碱性状变化的异同

THE COMPARISON OF SALINE-ALKALIPROPERTIES IN SEASHORE SALINE AND ALKALINE SOIL IN THE DESALINIZATION IN JIANGSU

江苏省境内滨海盐土和花碱土是两类成因不同、盐碱性状有别的盐碱土。在脱盐过程中由于盐分组成发生变化,pH 值在滨海盐土中先增后减,花碱土中单一减小,但两者的 pH 值的变化都受溶液中 Ca^(2+)浓度所控制。脱盐过程中,盐渍土中的 Na^+的淋失速度比 Ca^(2+)快,因此,无论是滨海盐土还是花碱土的钠吸附比和碱化度都下降.当土壤盐分 F 降到0.02%左右时,原来的滨海盐土和花碱土的溶液盐分组成都变为以 CaHCO_3为主,pH 值一般下降到8.5以下,碱化度下降到5%以下,成为非盐碱化的潮土.

The formation and saline-alkali properties of the seashore saline and alkaline soil in Jiangsuare different.Because of the variation of Ca^(2+)concentration in the desalinization,pHwas increased first anddecreased afterwards in the seashore saline soil,but it was decreased all the way in the alkaline soil,Eitherin seashore saline soil or in alkaline soil,the ESP(exchange sodium percentage)and SAR(sodiumadsorption ratio)were all deccased,because Na^+ was washed faster than Ca^(2+)when the salt contents weredecreased to about 0.02%,the chemical compositions of both soil solutions were placed by Ca(HCO_3)_2 aschief component,pH usually was decreased to under 8.5,the ESP was decreased to under 5%,and the twosoils transformed into non-salinization alluvial soils