上海水稻土的母质多来源于长江冲积物,由于沉积环境和沉积年代不同而区分为湖积物和老长江冲积物以及近代冲积物。中部岗身地带是较老的长江冲积物,质地多为粉砂壤质,石灰淋溶时间较长,pH中性偏碱。岗身以西湖相沉积物,多为粘壤,pH中性或微酸性。不同沉积物发育的水稻土,其粘粒的硅、铁、铝氧化物及硅铝率、硅铁率和盐基代换量也有差异。根据沉积母质和水型不同,剖面中铁、锰物质的淋溶沉积程度,划分为渗育型、潴育型、脱潜型、潜育型水稻土。近年来,我们在以往研究的基础上,进一步研究了不同起源和水型上水稻土剖面中铁、锰的含量和 Most of the parent material of Shanghai paddy soil comes from the Yangtze River alluvial deposits, which are divided into lacustrine sediments and old Yangtze alluvial deposits and modern alluvial deposits due to different depositional environments and sedimentary ages. The middle part of the Yangtze River is more elderly alluvial sediments, mostly silty loam texture, lime leaching longer, neutral pH alkaline. Kong Lake West Lake sediments, mostly clay, pH neutral or slightly acidic. In paddy soils with different sediments, the contents of silicon, iron, aluminum oxides and silicoaluminites, ferrosilicon rates and base substitutions of clay are also different. According to sedimentary parent material and water type, the profiles of iron and manganese deposition of the degree of leaching, divided into seepage type, retention type, off-type, latent type paddy soil. In recent years, based on previous studies, we further studied the contents of iron and manganese in paddy soil profiles of different origins and water types and