中国土壤系统分类中盐成土及其相关土壤诊断标准的修订建议

对土壤进行科学分类是土壤资源开发和利用的基础,也是土壤调查制图的基础,在农业生产、土地利用的决策和管理中发挥着重要作用,标志着土壤科学的发展水平.目前国际上土壤分类主要有《美国土壤系统分类》(以下简称《ST》)1]和《世界土壤资源参比基础》(以下简称《WRB》)2],我国从1984年开始的中国土壤系统分类研究,也已形成了具有中国特色的《中国土壤系统分类》(以下简称《CST》)3]成果.这三个分类体系都是以定量化的诊断层和诊断特性为基础的多阶层土壤分类体系.

Suggested revisions of diagnostic criteria for Halosols and relevant soils in Chinese Soil Taxonomy

The criteria for classifying soil as saline taxon are different in different soil classification systems. Soils are named as saline soil in Chinese Soil Taxonomy, World Reference Base for the Soil Resources and US Soil Taxonomy, respectively, when soil has a salic horizon starting within 30 cm, within 50 cm and within 100 cm from the soil surface. This paper describes some soil profiles that were classified into saline taxon in CST, WRB and ST before they are reclaimed, to see if these soils after a long history of irrigation are still classified into saline taxon in the three soil classification systems. The results show that the salts were leached into certain depth, the salic horizons were observed at different depth from the surface, many profiles could not be classified as Orthic Halosols as identified earlier, some of them could not be classified as Solonchaks, few of them even could not be classified as Salids. The depth of salic horizon is related to the amount of irrigation water and irrigation models. According to the present study, we suggest that the criteria of ST should be taken for keeping reclaimed saline soils in the saline taxon, i.e. Soil classification should not be changed by irrigation.