我国土壤资源的现状及特点 (10).ppt

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1、2.4.1 Soil Formation Factor-Parent Material2.4.1土壤形成因素-母质 2.4.1 Soil formation factor-parent materialAt the end of the 19th century,Russian soil scientist,Dokuchaev,proposed five soil forming factors and established The Theory of Soil Forming Factors.In 1940s,American Hans Jenny proposed the concept

2、 of soil formation factor function:s=f(cl,o,r,p,t,);In the early 1980s,he proposed a series of soil occurrence functions:Climate function or climate series：s=f(cl,o,r,p,t,)Organism function or biological series：s=f(o,cl,r,p,t,)Relief function or relief series：s=f(r,cl,o,p,t,)Parent material function

3、 or parent material series：s=f(p,cl,o,r,t,)Time function or time series：s=f(t,cl,o,r,p,)Other functions based on other soil formation factors：s=f(,cl,o,r,p,t)2.4.1 Soil formation factor-parent materialSoils in whiteYellowRedCyanBlackDistribution of The Colorful Soils in China 2.4.1 Soil formation fa

4、ctor-parent materialFormation process of soil parent materialThe origins of parent materials 2.4.1 Soil formation factor-parent materialRock and mineralWeatheringPhysical weatheringChemical weatheringBiological weatheringParent materialsWeathered debrisSimple saltsSecondary mineralsResidual accumula

5、tion in situResidual parent materialTransported by stream or gravitySlope depositsDeluvial depositsAlluvial depositsRiverbed depositFloodplain depositOxbow lake depositDelta depositLacustrine deposits Marine depositsGlacial transport and depositionGlacial depositsWind handling and stackingAeolian de

6、positsLoessTransported by water and deposit around rivesThe function of parent materials It directly affects the velocity and direction of soil formation.The parent materials have profound effects on the physical and chemical properties of soils.2.4.1 Soil formation factor-parent materialThere is a“

7、kinship”between the parent materials and the soils：1The mechanical composition of the parent material affects the mechanical composition of the soil.2Parent material is the initial source of mineral elements(except nitrogen)in soil.3The stratification of parent materialThe stratification of parent m

8、aterial is also passed on to the soil.2.4.1 Soil formation factor-parent materialThe function of parent materials The differences among rocks,parent materials and soilsRocks Parent materials SoilsHard,firm and nonpe-netrating;They cannot retain water;Adsorption,biological activity,nitrogen and solub

9、le nutrients are not found in rocks.Loose and porous,highly permeable,with certain water storage and adso-rption,a small amount of soluble nutrients,little biological activity,and a variety of native minerals.Loose,porous,strong permeability,strong water storage and absorption;It has profile configuration(stratification);High content of organic matter,strong biological activity,and high content of various types of secondary minerals and nutrients.2.4.1 Soil formation factor-parent material谢谢THANK YOU