Brahim N. auteur aut IRD Blavet Didier auteur aut IRD Gallali T. auteur aut IRD Bernoux Martial auteur aut IRD text journalArticle eng text/pdf born digital access Restoration of atmospheric carbon in soils has principal many good effects. Arid lands cover more than 40 % of the global earth area, but only stock 16 % from the global carbon stock. It seems to be a suitable solution for this environmental issue, but still all variables controlling organic carbon in such kinds of soil, was ignored. This study aims to develop two models of organic carbon under clayey and sandy soils in semi-arid Mediterranean zones basing on physical and chemical soil properties. For establishing both models, structural equation modeling was used. For modeling organic carbon, two Tunisian soil databases composed from clayey and sandy soils made respectively, of 450 and 602 soil horizons were used. Using the two databases for all properties, the principal component analysis shows two components for clayey soil; (i) chemical properties and bulk density and (ii) physical properties. For the sandy soil it reveals two components; (i) chemical properties and (ii) physical properties. According to the derived components for each soil category, two models have been built. Structural equation modeling results show that clayey model has proved that organic carbon was controlled by chemical properties and bulk density more than physical properties and sandy model has proved that organic carbon was controlled by chemical properties more than physical properties. The root mean square errors of approximation were 0.079 and 0.050 for the clayey and sandy models, respectively. Then these two models were validated with two other databases from Tunisian dryland soils. specialized Drylands Linear causal modeling Organic matter Path analysis Soil texture 068 020 8 2 305-320 2011 1735-1472 https://www.documentation.ird.fr/hor/fdi:010053375 1735-1472 [F B010053375] https://www.documentation.ird.fr/hor/fdi:010053375 https://www.documentation.ird.fr/intranet/publi/2011/03/010053375.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2011-04-07 2017-08-23 fdi:010053375 fre