MORPHOLOGICAL AND CHEMICAL CHARACTERISTICS OF SOIL PROFILE FOR POMELO CULTIVATION IN MO CAY BAC DISTRICT, BEN TRE PROVINCE

Abstract

The study was performed to determine the morphological and chemical properties of soil for farming pomelos in Mo Cay Bac district, Ben Tre province. The classification and soil morphology was described according to FAO, WRB and the Munsell’s chart. Soil was sampled according to horizons of three profiles of soil for pomelo cultivation to analyze soil chemical features. The results showed that the three soil profiles belonged to the deeply potent acid sulfate soil, with the appearance of acid sulfate bearing materials at > 60 cm depth. The values of pH_H2O and pH_KCl at the surface horizon of the three soil profiles were roughly 3.22 - 6.43 and 2.71 - 4.66. Simultaneously, the toxicities of Al³⁺ and Fe²⁺ were low, with 0.501 - 3.07 meq Al³⁺ 100 g^-1 and 0.507 - 1.51 mg kg^-1, respectively. The total nitrogen content was from intermediate to high. The available nitrogen and soluble phosphorus contents were 24.5 - 50.4 mg NH₄⁺ kg^-1, and 4.95 - 367.7 mg P₂O₅ kg^-1, respectively. However, the contents of Al-P, Fe-P and Ca-P were high in the surface horizon, and were 241.3 - 249.3, 431.3 - 504.7 and 90.4 - 203.1 mg kg^-1, respectively. Moreover, the organic matter content was classified as low to intermediate, while the cation exchange capacity was low. Therefore, it could be concluded that the pomelo farming soil in Mo Cay bac district, Ben Tre province had low fertility.