酸性紫色土盐基饱和度和pH值的关联分析及分类学意义  

Correlation Analysis between Base Saturation and pH of Acidic Purple Soils and Its Taxonomic Significance

作　　者：刘彬 慈恩[1] 刘俊延 胡瑾 陈洋洋 LIU Bin;CI En;LIU Junyan;HU Jin;CHEN Yangyang(School of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院,重庆400715

出　　处：《西南大学学报（自然科学版）》2023年第4期65-72,共8页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金项目(41977002);中央高校基本科研业务费专项资金项目(XDJK2020B069).

摘　　要：探讨酸性紫色土pH值和盐基饱和度(Base Saturation,BS)间的关联性,为酸性紫色土BS的估算及分类提供科学参考及建议.在重庆市采集24个典型酸性紫色土剖面的77个发生层土样,测定其机械组成、pH值、BS和有机质等理化性质,采用回归模型和BP神经网络两种模型,对pH值和BS数据进行拟合分析.回归模型的拟合结果表明,一元二次拟合方程的拟合效果优于一元线性方程拟合效果.BP神经网络模型中随着输入与BS相关数据类型的增加,拟合准确度更高.基于拟合模型,假设BS的取值为50%时,得到pH值的范围为5.11~5.21.采用一元二次拟合方程y=-0.02024x 2+0.34642x-0.74023(y为BS,x为pH值),能够较好实现酸性紫色土BS的估算,在开展紫色土系统分类高级单元划分时,建议优先采用BS<50%为“酸性”诊断标准,若需使用pH值为“酸性”检索条件,建议将原标准pH<5.5调整为pH<5.1.To investigate the correlation between base saturation and pH of acidic purple soils,and to provide scientific reference and suggestions for the estimation of BS and the soil taxonomy of acidic purple soils,seventy-seven purple soil samples with different parent material development were collected in Chongqing for determination of physicochemical properties such as mechanical composition,pH,BS and soil organic matter,and conducting fitting analysis with regression model and BP neural network.The fitting results of regression model showed that the fitting effect of quadratic equation is better than that of linear equation.The fitting accuracy is higher in the BP neural network model with the increase of input the BS-related type of data.Based on the fitting model,assuming that the value of BS is 50%,the derived pH range is 5.11-5.21.The quadratic equation of BS fitted by pH is a more direct and convenient estimation method.The fitting effect of trained BP neural network model is the best when there is enough data of BS,pH,soil organic matter and mechanical composition.It is suggested that in the Chinese Soil Taxonomy at the higher category level,the qualification condition of BS<50%should be preferred in the retrieval condition of“acidity”.If pH should be used as the retrieval condition,it is suggested to change pH<5.5 to pH<5.1 as the retrieval condition of acidity of purple soil,which is more consistent with the actual situation.

关 键 词：紫色土 酸碱度 盐基饱和度 拟合方式 土壤系统分类 

分 类 号：S155.2[农业科学—土壤学]