The Applications of Chemical Analyses of Sediments and Soils in ...

Organic carbon can be measured by converting carbon to carbon dioxide in afurnace and collecting and measuring the CO 2. The Walkley and Black chromic acid wetoxidation method (Jackson, 1958) can be used to determine readily oxidizable organicmatter even in the presence of up to 50% CaCO 3 . Recoveries of 60-86 per cent of theorganic carbon are obtained. Other oxidizable material and higher oxides of manganeseand reduced iron interfere. Low temperature ignition at 350 - 400°C for 7 - 8 hours canbe used. Using some West Virginia mine soils there was a high correlation (r = 0.977)between low temperature ignition and the Walkley - Black method although the resultswere almost twice as high (Smith et al, 1974):Y (Walkley-Black) = 0.3079 + 0.4122 x IgnitionLoss on ignition is routinely analyzed at the Ministry of the Environment as theweight loss at 600°C. Analysis of major nutrients is also important in relation toestablishing vegetation on mine soils.Available phosphorus can be measured after acid or alkaline extraction. Acidextraction has been found to give unreliable results on alkaline soils due to solution ofcarbonate weakening the strength of the acid, or solution of non available apatite. Onacid soils solution of iron can give erratic results (Smith et al, 1974). Sodiumbicarbonate extraction has been found to relate to plant response (Olsen et al, 1954;Olsen and Dean, 1965) and a satisfactory correlation (R = 0.86 ) with acid ammoniumfluoride extractable P for acid minesoils (Smith et al, 1974).31