1:250000 land quality geochemical assessment of Shouning County, Fujian Province

In this paper, the topsoil environmental quality and nutrient quality were evaluated by the calculation techniques of single factor index and integrated factors on the basis of topsoil heavy metal elements and nutrient elements data with high accuracy provided by the multi-purpose geochemistry survey in Shouning County of Fujian Province in the light of the environmental quality standard for soils（GB15618—1995）and relative industrial standard. On such a basis, the lands were graded according to the geochemical quality. Some conclusions have been reached: the land quality is comparatively good on the whole, i.e., the land mainly belongs to the third and fourth grade, which accounts for 80.80% of the whole area, with the soil being comparatively clean; Seenriched soil is distributed in the soil of the third and fourth grade, accounting for 10.46% of the survey area, and it is suitable for the development of general agriculture and selenium- enriched agriculture. The next is land of the first and second grade quality, accounting for 13.13% of the survey area, and such land is suitable for development of green or pollution-free agricultural products, and should be protected and utilized reasonably. The area of land of fifth and sixth grade quality is rather insignificant, only accounting for 6.07% of the survey area.