THE DEVELOPMENTAL CHARACTERISTICS AND CLASSIFICATION OF TWO PADDY SOILS WITH DIFFERENT ORIGINS IN GUANGDONG PROVINCE

The paper deals with the developmental characteristics and classification of two types of paddy soils originated from basalt-derived latosol and coastal marsh respectively in Guangdong province. The research results indicated: The H/F ratio in soil humus tended to increase with the prolongation of submer-gence; the soil characteristics changed in different ways in the developmental process of latosol and coastal marsh to paddy soils; the differences between the soils with different origins were significant in terms of pH value, CEC, ferruginous crystal and ratio of ferruginous crystal and colloid, which reflected the strong influence of original soils. But the differences of characteristics between the soils with same origin but different water regimes were not significant; paddy soil should be an independent soil group, and the distinction of its developmental characteristics and its classification could be based on the soil profile morphology, ratio of ferruginous crystal and colloid, ratio of H/F in humus, pH, total base content, base saturati n etc; the tested soils could be classified into two sub-groups, i. e. lateritic paddy soil and coastal marshy paddy soil. The sub-groups could be further divided into different families according to their water regimes (submergic, periodically waterlogged, gleyed, degleyed etc) .