昌图县耕地棕壤酸度变化特征的初步研究

昌图县位于辽宁省铁岭市北部,是辽宁省的产粮大县之一。通过对大田调查采样与室内分析相结合的方法,研究了昌图县耕地土壤酸度变化特征。结果表明：昌图县耕地土壤类型以棕壤为主,此外还有少量的风沙土和草甸土。在3 750个3种类型土壤土样中,pH〈5.0（强酸性）和pH 5.0~6.5（酸性）的土样占总调查土样的75.68%。中性土样占16.56%;其中棕壤酸化程度最大,pH〈5.0（强酸性）和pH 5.0~6.5（酸性）的土样分别占总调查土样的1.17%、87.28%。与第二次土壤普查相比,各乡镇土壤pH均有所下降,其下降值为0.16~1.43个单位。实验数据分析得出：土壤pH与土壤阳离子交换量和盐基饱和度呈正相关关系;与土壤交换性酸（交换性H＋和交换性Al3＋）呈负相关关系。

Study on the Feature of Acidity Change in Brown Soils of Changtu County

Changtu county locates in the north of Tieling. It is one of the major grain-producing counties in Liaoning province. Using the method of combining the field investigation and analysis indoor, the feature of acidity change in soils of Changtu county was studied. The results showed that besides a small amount of sand soil and meadows soil,soils of Changtu were mainly brown soil. The proportion of the three types of soil which pH〈 5.0（strongly acidic） and pH 5.0-6.5（acid） accounted for 75.68% of the 3 750 survey soil samples,the neutral soil accounted for 16.56 %. Brown soil＇s acidification degree was the largest. The soil samples of the pH〈 5.0（strongly acidic） and pH 5.0-6.5（acid） accounted for 1.17% and 87.28% ,respectively. Compared with the second soil census,the soil pH of the towns all decline between 0. 16-0. 13. The results showed that the soil pH had positive correlations with CEC and BS and negative correlations with exchanged acid（exchanged H＋ and exchanged AP＋ ）.