Study On Soil Podzolic Process Of Grey Forest Soil And Black Soil In The North Of Hebei Province In China

The podzolic process is one of the important soil forming processes, and exists in the podzolic soilgenerally. The occurrence and development of podzolic process need special environment, and podzolicsoil exhibit the particular profile morphological characteristics and physical and chemical properties.There are many literatures about the characteristics of podzolic soil which have obvious podzolicprocess, for example podzol (or spodosol). However, there is little reseach of the soils which podzolicprocess is not obvious, and we have no idea about the characteristics of these soils.When having a survey in the field, the author found the geographical environment of greyforestsoil and black soil in the Bashang Plateau of the north of Hebei province in China were similar to thegeographical environment which the podzolic process needed. Although there were no obvious greywhite eluvial horizon and spodic horizon in the profile of greyforest soil and black soil, there were muchSiO2power illuviating on the middle and bottom of the profile, and that there were weak process ofcomplexing eluviation and illuviation in the soil. Therefore, the author thought those soils occurred thepodzolic process possibly. But there were few literatures about the podzolic process of greyforest soiland black soil in the north of Hebei province. Hence, the paper planed to analyse the distributioncharacteristics of organic matter, Fe, Al etc. in the profile of greyforest soil and black soil in the north ofHebei province through surveying in the field, soil profile observation and physical and chemicalproperties determination in order to confirm the characteristics of eluviation and illuviation of the twosoils, and then explaining the feature of the podzolic process of greyforest soil and black soil in thenorth of Hebei province and found environmental effection on the podzolic process. The mainconclusions of the paper are following:(1) Greyforest soil in the north of Hebei province formed in the cold-temperate zone subhumidclimate and coniferous forest vegetation or coniferous and broadleaf mixed forest vegetation. There washigh humus accumulation process in the soil, and the organic caborn of humus accounted for37.80%～70.01%of the total organic carbon; the soil had weak acidificaton and decalcification process, and therewas no lime reaction in the genetic horizons; the soil occurred weak eluviation and illuviation process inthe weak acid conditon; much SiO2power illuviating on the surface of structure of middle and bottomof profile.(2) Black soil in the north of Hebei province formed in the cold-temperate zone subhumid climateand meadow steppe vegetation. There was high humus accumulation process in the soil as well asgreyforest soil, and the organic caborn of humus accounted for34.04%～66.17%of the total organiccarbon； the soil occurred weak eluviation and illuviation process in the semihumid conditon, and thesoil had decalcification process, so there was no lime reaction in the genetic horizons; the soil reactionwas from weak acid to neutral; small amounts of SiO2power illuviating on the underpart of soil.(3) The moisture was one of the improtant factors in the geographical environment, so it had moreinfluence to the development of greyforest soil and black soil of the northern of Hebei province. The semihumid conditon in the north of Hebei province didn't satisfy the need of the podzolic processdevelopment, the precipitation was little while evaporation was more, so the soil couldn't form humidenvironment. Moisture deficiency hindered forest litters decomposing into organic acid and affected thevelocity and quantity which the organic acid infiltrated into the soil, and then affected the developmentof soil acid and the eluviation of substances.(4) The profile differentiation characteristics of greyforest soil and black soil in the north of Hebeiprovince was not obvious, and illuviation horizon developed weakly. The color in the whole profile wasdark, and there were no grey white eluviation horizon and illuviation horizon of enriching Fe, Al andorganic matter. The soil horizon were deep, and the content of organic matter were high； granulestructure and crumb structure were the main soil structure；there were much SiO2power on the lowerpart of soil； there still were little rust streak and rusty spot in the bottom of soil, but they were veryweak and difficult to find because of the covering of humic；there were no lime reaction and NaFreaction in the genetic horizons, or the NaF reaction was weak.(5) From the profile distribution characteristics of substancese, clay, organic matter, Fed, Ald, Feox,Alox, Fep, Alp of greyforest soil and black soil of the northern of Hebei province existed weakeluviation and illuviation phenomenon. Therefore, greyforest soil and black soil of the northern ofHebei province occurred the acid eluviation process of Fe and Al, and the complexation eluviationprocess of Fe, Al and organic matter, but the two porcesses were weak. Then the analysis results provedfurther that there were podzolic porcess in the greyforest soil and black soil of the northern of Hebeiprovince, but it was unapparent podzolic process—hidden podzolic process.