Total carbon organic carbon and organic matter

Total Carbon, Organic Carbon, and Organic Matter

Total Carbon, Organic Carbon, and Organic Matter 1

A simple method for routine determination of organic carbon in soil by a modified Mebius procedure is described It involves (a) digestion of the soil sample with an acidified dichromate (K2Cr2O7‐H2SO4) solution for 30 minutes in a Pyrex digestion tube in a 40‐tube block digester preheated to 170°C and (b) estimation of the unreacted dichromate by titration of the cooled digest with an acidified solution of ferrous ammonium sulfate with use ofN‐phenylanthranilic acid as an indicator The method is more rapid and precise than the Mebius procedure commonly used for routine analysis of soils for organic carbon, and the only equipment required for its use is equipment now commonly used for routine Kjeldahl analysis of soils for total nitrogen

A rapid and precise method for routine determination of organic carbon in soil

The environmental fate of phthalate esters: A literature review

A simple and precise procedure for estimating total N in plant tissue is described; a modification is also described for analysis of samples containing high nitrate concentrations. Plant tissue samples are placed in pyrex Folin-Wu tubes and digested with a salt-catalyst-sulfuric acid mixture by heating the tubes in an aluminum block. Samples are digested at the boiling point of the mixture for 60 min after initial clearing of the digests. Analyses of diverse plant materials, containing from 0.006 to 0.3% NO₃-N₃ indicated that the proposed and standard AOAC procedures yielded essentially the same total N values. The coefficient of variation for the proposed methods varied from 0.87 to 1.10%. The tube digestion procedures described allows digestion of 60 plant samples simultaneously and thus greatly improve the efficiency of total N determinations.

Determination of Total Nitrogen in Plant Material1

Determination of Total Phosphorus in Soils: A Rapid Perchloric Acid Digestion Procedure

Total Nitrogen Analysis of Soil and Plant Tissues

A Simple Digestion Procedure for Estimation of Total Nitrogen in Soils and Sediments

Research on processes leading to gaseous loss of N from soils has been stimulated by the accumulation of evidence indicating that crop recovery of fertilizer N is often < 50070 of that applied and that a substantial amount of N added to soils is apparently volatilized during the growing season. Nitrogen balance experiments conducted with lysimeters have suggested that N deficits (presumed to result from volatile N losses) are of the order of 15 to 20% (Allison, 1955, 1966, 1973). Furthermore, experiments involving use of 'SN-labeled fertilizers have confirmed that a significant proportion of applied N is lost from soils during cropping (for reviews, see Broadbent & Clark, 1965; Allison, 1973; Makarov & Makarov, 1976). Bacterial denitrification may account for some of the N deficits. However, other mechanisms of gaseous N loss, such as NH3 volatilization and NO z reactions in soil, probably account for a substantial proportion of the N deficits observed in many experiments (Allison, 1965, 1966, 1973; Broadbent & Clark, 1965; Woldendorp, 1968).

Darrell W. Nelson

Papers

Determination of Total Nitrogen in Plant Material1

Determination of Total Phosphorus in Soils: A Rapid Perchloric Acid Digestion Procedure

Total Nitrogen Analysis of Soil and Plant Tissues

A Simple Digestion Procedure for Estimation of Total Nitrogen in Soils and Sediments

Gaseous Losses of Nitrogen Other Than Through Denitrification