Estado atual da determinação do carbono no solo I: em solos contendo de 0,2 a 4,0% de carbono

Abstract

This paper describes the date obtained in the determination of the soil carbon by two methods. The dry combustion method, measuring gasometrically the CO2 in a buret, and the wet oxidation method using chromic acid (from potassium dichromate and sulfuric acid) with subsequent estimation of the excess of chromic acid by titration with sodium thiosulfate (iodometry). Ten different soils samples of carbon content of 0.2 to 4.0% weve analysed by both methods and five determinations were made in each sample. The data obtained are presented in Table 1:The wet oxidation gave 68.8 to 93.4 per cent recovery of carbon as compared with the dry combustion method. The dry combustion method, measuring the CO2 gasometrically in a buret, is very rapid (about 5 minutes) and gives te total soil organic carbon.