GEOCHEMICAL EVALUATION OF LAND QUALITY IN MULING RIVER-XINGKAI LAKE PLAIN

Based on the soil nutrient element data of 1:250 000 land quality geochemical survey in Muling River-Xingkai Lake Plain, referring to the Code for Land Quality Geochemical Evaluation(DZ/T0295-2016), the single index evaluation method is used to evaluate the soil nutrients respectively and comprehensively in the region. The results indicate that the study area is characterized by rich or relatively rich total nitrogen, total phosphorus, organic matter, sulfur, manganese, molybdenum and iron oxide, medium (third-grade) total potassium, and deficient calcium oxide, magnesium oxide, boron, zinc and copper. The soil nutrient composite indexes show the land of Muxing Plain is mainly rich (first grade) and relatively rich (second grade). The Se-rich land area of 344 km² is recognized, with soil Se content of 0.4×10^-6-0.79×10^-6, averagely 0.44×10^-6, accounting for 2.07% of the total area.