淋洗状态下保护地土壤pH与盐分含量及其组成关系的研究

Study on Relationship between pH Value of Protected Field Soil and Its Salinity Content and Composition under Leach Condition

以沈阳地区酸化比较严重的保护地土壤为研究对象,采用淋洗模拟试验的方法,通过测定淋洗后土壤pH值和全盐量、淋洗出的盐分离子含量,研究了土壤pH值与离子组成、含量之间的关系。结果表明:①土壤pH值与土壤全盐含量呈显著负相关关系,即土壤pH值随土壤全盐量的降低而逐渐增加,但盐分的减少对土壤pH的影响在淋洗后期明显大于前期;②土壤pH值与阳离子、阴离子的组成即相对比例有关,其中与K+和其他4种阴离子呈曲线负相关关系,与另外3种阳离子呈直线负相关关系,且相关性均达到极显著;③随着淋洗次数的增加,NO3-、SO42-等离子含量在全盐含量中所占比例而不断下降,与此同时土壤pH值却在不断的上升,而Ca2+、Na+等盐基离子在全盐中的相对比例的上升也是导致土壤pH值上升的重要因素。

The protected field soil, of which the acidification is serious in Shenyang region, is taken as studying object in this paper. Through the experimental method of leach, the pH value of soil, total salt content and salt ion content which is leached are measured, and the relation among ph value , composition and content of ion is studied. The results are list as follows. Firstly, there is a significant negative correlation between soil pH value and soil salinity content, the soil pH value becomes higher with the decrease of the soil salinity content, but the influence is bigger in later period than pre-period. Secondly, the soil pH value has a relationship with the composition of cation and anion of soil. Among these ions, K＋ and other four anions have a curve negative correlation with the soil pH value, while the other three cations have a straight line positive correlation with the soil pH value, both the two correlations achieve the significant level. Thirdly, with the increase of leaching times, the proportion of NO3^- and SO4^2- in total salty content decreases, but the soil pH value increases, at the same time the proportion of Ca^2＋ and Na^＋ in total salty content increases, which is also an important factor for the increase of soil pH value.