In order to provide technical support for agricultural production and fertilization,and soil quality protection in Kunming and similar areas,phosphate-acetic acid extraction-barium sulfate turbidimetric method was used to determine the physical and chemical properties of cultivated soil,such as available sulfur and water-soluble salt. Afterwards,the content of available sulfur and its correlation with secondary salinization were statistically analyzed. Results: The soil available sulfur content in nine counties (cities and districts) of Kunming was at a high level,with an average of 114 mg/kg;Due to the large protected cultivation area,high application rate of chemical fertilizer and high content of water-soluble salt,the average content of water-soluble salt was more than 1.70 g/kg in Jinning,Guandu and Songming,where were the main producing areas of vegetables,flowers and traditional growing areas. The linear correlation equation between the total amount of water-soluble salts and the content of available sulfur in soil was y=0.008 3x+0.670 8,R^2 =0.795 9,which showed a very significant correlation between the total amount of water-soluble salts and the content of available sulfur. The content of water-soluble salt in the main producing areas and traditional planting areas of vegetables and flowers is relatively high,and the content of available sulfur in soil is an important factor leading to soil secondary salinization.
Guizhou Agricultural Sciences