| To provide a comprehensive evaluation of soil quality, soil from coastal saline area in the Yellow River delta was used to examine soil organic matter, total nitrogen, alkaline hydrolysis nitrogen, available phosphorus, available potassium, total salt content, pH and clay content of 0～30 cm soil layer, which are relevant with plant growth in this area. The values of soil quality were measured by the method of fuzzy comprehensive index. Kriging interpolation method and natural breaks were additionally used for the comprehensive evaluation of soil quality. A soil quality classification was established through interpolation and natural breaks in ARCGIS. The result showed that: value of the soil quality comprehensive evaluation fell down to somewhere between 0.194 and 0.376, indicating that the soil quality in this area was generally poor. The soil quality in northeastern coastal shoal was the worst. With the increase of distance from the coastline, soil quality comprehensive evaluation value became increased, and the high values appeared in the southwest and northwest regions of the research area, suggesting a circular spatial distribution. According to the classification result, grades 4 and 5 were lowest in soil quality with areas of 804.60 km2 and 834.73 km2, respectively, accounting for 51.46% of the entire research region. In addition, this particular area included beach, bare land and salt wasteland, which have been characterized as deficiency in nutrients, high level of soil salt content and difficultness in soil desalinization. Making reasonable use of the soil might be a primary approach for its quality improvement, such as planting salt tolerant crops and developing aquaculture or constructing salt pond. Additional improvement measures should also be put forward to soil lands with other grade. |