上海疚通大￥ SHANGHAI JIAO TONG UNIVERSITY Page.01 ·Investigation methods土壤野孔隙度及有机物的计算方法 Soil porosities土壤孔隙度需要通过土壤容重 soil bulk density和土壤比重计算soil specific gravity,as Contents of total porosity (%)=(1-soil bulk density/soil specific gravity)]x100 0 Soil organic content土壤有机物含量需要通过 WaIkIey-Black method方法计算： Figure 4-2-3.Soil sample collection Soil organic content (g/kg)={[c(Vo-V)x3.0x10-3x1.33]/sample weightx1000}x1.724 where c=0.8mol-L1(1/6 K2Cr207)standard solution concentration (unitless),Vo=volume of FeSO4 used for blank titration(mL),V=volume of FeSO used for sample titration(mL),3.0 is molar mass of carbon atom(g.mol-1), 103 is conversion from mL to L,1.33 is oxidation adjusting coefficient,and 1.724 is the average conversion factor for changing soil organic carbon to soil organic matter.Page . 01 • Investigation methods 土壤孔隙度及有机物的计算方法 • Soil porosities 土壤孔隙度需要通过土壤容重 soil bulk density 和土壤比重计算 soil specific gravity, as Contents of total porosity (%) = (1-soil bulk density/soil specific gravity) ]100 Soil organic content (g/kg) = {[c( V0 -V) 3.010-31.33]/sample weight1000}1.724 • Soil organic content 土壤有机物含量需要通过 Walkley-Black method 方法计算： Figure 4-2-3. Soil sample collection • where c=0.8mol·L -1 (1/6 K2Cr2O7 ) standard solution concentration (unitless), Vo= volume of FeSO4 used for blank titration (mL), V= volume of FeSO4 used for sample titration (mL), 3.0 is ¼ molar mass of carbon atom (g.mol -1 ), 10-3 is conversion from mL to L, 1.33 is oxidation adjusting coefficient, and 1.724 is the average conversion factor for changing soil organic carbon to soil organic matter