Soil–environment impacts Chemical Properties of Selected Soils from the

Saline and sodic soils occur in large areas on the North China Plain (NCP). This presents a serious problem for sus-tainable agricultural development in the area. This study identified and characterised saline, sodic and sodic-saline soils on the NCP and recommended some strategies to deal with salinity in the region. Three distinct regions were identified: the coastal, middle and western zones. The parent material of the soils is river alluvium. Illite (Hydromica) is the dominant layer silicate mineral; smectite, kaolinite and chlorite are subdominant. SOIL salinisation is a growing problem in agriculture worldwide. As we try to meet global needs for agricultural production, more and more countries are concerned about the increasing problem of salinity. China is one of the nations that have a serious problem with saline soils; the North China Plain (NCP), a major food production area, has especially suffered from this problem. For instance, in the early 1950s the NCP had more than 2 million ha of saline soils; at the end of the 1950s, 4 million ha were affected, and in the mid-1980s only 2 million ha were affected. This overall decrease in extent of saline affected soils has been largely due to changes in irrigation practices and an associated fall in the depth of the groundwater table in the region. Areas where the extent of salinisatio