Characteristics Of Calcareous Soils From Henan Province And Their Basic Categories In Chinese Soil Taxonomy

As so far,higher categories of Chinese Soil Taxonomy have been established in forms of keys to soils.However,research in basic categories of them are still focused on.Thus,in recent years,research in soil series more and more focus on how to analyze and use soil series in better ways,such as soil series comparison,data frame of soil series and the relationship between soil series and agriculture,ecology and Environment.At the meantime,calcareous soils which is known as major farming soils in north China are widely distribute coupled with Ustic soil moisture regime.And calcification exist eventually and is affected deeply by parent materials,terrains,rainfall,plants and even human activities.As a result,morphological characteristics of profiles differ much.So it is significant to research and illustrate that how to descript,interpret and use these soils under Chinese Soil Taxonomy(3rd version).Calcareous soils coupled with Ustic soil moisture regime were investigated and sampled for the purpose of researching the calcification features within pedons.From the perspective of Chinese Soil Taxonomy,in forms of higher and basic categories,classifying these calcareous soils is focused in this study.With the help of soil-landscape influence method,spatial features of calcareous soils were explored and illustrated on the basis of samples from Zhengzhou.This study found that weakly-developed calcareous soils in study area are mostly classified as Calcaric Endorusti-Ustic Cambosols and Typic Hapli-Ustic Cambosols.And Typic Hapli-Ustic Cambosols eventually includes large number of soils in which morphological features differ as a result of different degrees of calcification.On the basis of soil-forming environment,this process is largely affected deeply by parent materials,terrains,rainfall,and so on.Besides,calcic horizons mostly form on toe slope and fridge area of alluvial fans,where soil materials more likely gather instead of erosion.Based on higher categories of calcareous soils in Chinese Soil Taxonomy,basic categories which are soil families and series were classified according to the features of soils in Henan.Consequently,methods to soil series were proposed in this paper and redefined the concept of Characteristic horizons for a better soil series management in a way of “logical gram of soil series”.According to these criteria on calcareous soils,26 soil families and 40 soil series were established representing typical morphological and landscape features within study area.On the other hand,relationship between calcareous series and their landscape environmental elements were established and testified via fieldwork.On the basis of former research,traditional soil species in Zhengzhou were revised based on pedomorphological charateristics for being cross-referenced to series.And then methods and results were illustrated in this research.In this study,revised “calcic horizon” and “Calcic Hapli-Ustic Cambosols” were firstly proposed for “Chinese Soil Taxonomy(4th)”.In revised calcic horizons,visible secondary carbonates in quantitative definition would be firstly keyed out ahead of carbonate content by weight in soil matrix.And Calcic Hapli-Ustic Cambosols effectively descript and identify calcareous soils with calcic horizons,instead of messing up.On the basis of higher categories,26 soil families and 40 soil series largely represent typical calcareous soils occurred in study area.And established models of soil series and their landscape environmental elements were testified and basically reflect the spatial features in small-scale regions.At the meantime,to be honestly,influencing results is not perfect to simulate all soil series on the basis of testified fieldwork.