Abstract:

Rice-planting soils are the most important agricultural soils in China. It is a group of soils with hydroponic maturation in which human beings have cultivated rice for a long time, and a specific soil profile structure has been formed. “Chinese Soil Classification System” and “Chinese Soil Taxonomy”, two current soil classification systems in China, regard rice-planting soil as an independent soil type, which is called paddy soils and stagnic anthrosols, respectively. This group of soils is gradually formed under periodic irrigation-drainage, fertilization, cultivation and rotation. Its main soil formation processes include periodic redox alternation and iron-manganese leaching, base leaching and base restoration actions, and strong fixation and accumulation of organic carbon. At present, the quantitative research on this group of soils has been gradually improved. There is a more in-depth understanding of its distribution law in geographical space and genetic characteristics affected by terrain and soil parent material. However, the mechanism of vertical differentiation of iron oxides in the soils, the setting of some soil subgroups, soil quantitative identification standards, field investigation and mapping technology and the evolution of soil types caused by the change in utilization mode need to be further studied.

Key words: rice-planting soil, genesis, evolution, classification, spatial variation, Chinese Soil Classification System, Chinese Soil Taxonomy