On The Characteristics Of Typical Soils In Huaihua Area Of Hunan And Their Attributions In Chinese Soil Taxonomy

This essay,on the basis of the project of Chinese soil series survey in 2014,selected ten dry land soil profiles and three paddy soil porfiles from Huaihua area.Based on the study on the soil forming environment,profile morphological characteristics and physic-chemical properties,this essay established the diagnositic horizons and diagnostic characteristics of thirteen profiles as well as their classification system,identified the location of the tested sols in soil taxonomy and provided references for the soil taxonomy in Hunan Province.The main results are shown as following:(1)Based on the classification principals and methods provided by Chinese Soil Taxonomy(3rd edition),the diagnostic horizons of 13 typical soils developed from the shale,purple sand shale and limestone in Huaihua area,include Ochric epipedon,Umbric epipedon,Mollic epipedon,anthrostagnic epipedon,LAC-ferric horizon,Argic horizon,Cambic horizon and Hydragric horizon,the diagnostic characteristics include ali-evidence,ferrosol evidence,paralithic contact,reclioxic features,gleyic features,water regime of udic soil and temperature regime of thermic soil.(2)According to the diagnostic horizons and diagnostic characteristics of the shale red soil,it belongs to 4 orders such as Argosols,Ferrosols,Primosols and Cambosols;4suborders such as udic argosols,udic ferrosols,udic cambosols and orthents;5 groups such as Alliti-Udic Ferrosols,Ali-Udic Argosols,Ali-Udic Cambosols,Hapli-Udic Ferrosols and Usti-Orthic Primosols;5 subrgoups as Typic Alliti-Udic Ferrosols,Typic Ali-Udic Argosols,Typic Ali-Udic Cambosols,Typic Hapli-Udic Ferrosols and Typic Usti-Orthic Primosols.Based on the diagnostic horizons and diagnostic characteristics of purple sand shale soil,it belongs to cambosols order;suborders such as Udic Cambisols;2 groups as Ferri-Udic Cambosols,Ali-Udic Cambosols;and 2 subgroups as Red Ferri-Udic Cambosols,Typic Ali-Udic Cambosols.Based on the diagnostic horizons and diagnostic characteristics of paddy soil,it belongs to Anthrosols order;the suborder of Hydragric Anthrosols;2 groups such as Hapli-Stagnic Anthrosols and Fe-accumulation Anthrosols;and 2 subgroups such as Typic Hapli-Stagnic Anthrosols,Typic Fe-accumulation Anthrosols.(3)According to the classification standards for soil family and soil series,6 soil families as clay kaolinite type with acidic and hot Typic Alliti-Udic Ferrosols,and 7 soil series established for the shale red soil;3 soil families as clay loam and siliceous mixed type with non-acidic and hot Red Ferri-Udic Cambosols,and 3 soil series are established for purple sand shale soil;3 soil families as clay loam and siliceous mixed type with acidic and hot Typic Ali-Udic Argosols,and 3 soil series are established for paddy soil.(4)This essay,by comparing the soil genesis classification and the location in soil taxonomy,finds out the asymmetrical relationship of the shale red soil,purple sand shale soil and paddy soil,especially the complex corresponding relation in the higher categories of soil classification,which is several for one or one for several,while the corresponding relation in the basic categories of soil classification is simple,which is one for one or one for several.