交换性钙最大值为3772.8mg/kg，出现在棕壤性土。各亚类高低顺序

The maximum value of exchangeable calcium is 3772.8mg/kg, which appears in brown soil. The order of each sub-category is: brown soil>typical brown soil>tidal brown soil>white pulped brown soil. The content of exchangeable calcium in subgroups of Chao soil is not much different, and the content of each subgroup is lower than the average of the study area. The content of subgroups of Chao soil is slightly higher than that of salinized Chao soil. The average subgroup of the Chao soil is 1149.71mg/kg, the variation range is 114.5~2940.2mg/kg; the average salinized Chao soil is 1136.89mg/kg, the variation range is 763~1455mg/kg. The minimum value of 114.5mg/kg appears in the subgroup of Chao soil. The order of each sub-category is Chao soil>Saline Chao soil. <br>2) The exchangeable calcium content of soil in different land types. The soil exchangeable calcium content of different land types varies greatly, with the highest grain field, the average content is 1186.66, the variation range is 167.2~3772.8mg/kg, the standard deviation is 448.86mg/kg, the coefficient of variation is 37.83%; the vegetable field content is the lowest, the average is 847.01 mg/kg, range 347~1342mg/kg, standard deviation 750.63mg/kg, coefficient of variation 88.62%

The maximum exchange calcium is 3772.8 mg/kg and appears in brown soil. The order of each subcategory is: brown soil, typical brown soil, tidal brown soil, white slurp brown soil. The content of exchange caloric calcium of the subtypes of tidal soil was not much different, and the content of each subcategory was lower than the average of the study area. The content of tidal soil subspecies is slightly higher than that of salinized tide soil. The average of the tidal sub-class was 1149.71 mg/kg, with a variation of 114.5 to 2940.2mg/kg, and the average salted tide soil was 1136.89 mg/kg, with a variation of 763 to 1455 mg/kg. The minimum value of 114.5mg/kg appears in the tidal subclass. The order of sub-classes is tidal soil and salinized tide soil.<br>2) Soil exchange calcium content of different land types. Soil exchange calcium content varies greatly from land type to large, with the highest grain field, with an average content of 1186.66, a variation of 167.2 to 3772.8mg/kg, a standard deviation of 448.86mg/kg, a coefficient of variation 37.83%; lowest vegetable content, with an average of 847.01mg/kg, variable range of 347 to 1342mg/kg, standard deviation of 750.63mg/kg, coefficient of variation of 88.62%

The maximum exchangeable calcium was 3772.8 mg / kg, which appeared in brown soil. The order of the subclasses was as follows: brown soil > typical brown soil > Chao brown soil > albic brown soil. The content of exchangeable calcium in each subspecies of fluvo aquic soil had little difference, and the content of each subclass was lower than the average value in the study area. The content of subspecies in fluvo aquic soil is slightly higher than that in saline soil. The average of the sub types of fluvo aquic soil is 1149.71mg/kg, ranging from 114.5 mg / kg to 2940.2mg/kg, and that of salinized fluvo aquic soil is 1136.89mg/kg with a range of 763-1455mg/kg. The minimum value of 114.5mg/kg appeared in the subtidal group. The order of the sub types was fluvo aquic soil > saline aquic soil.<br>2) The content of exchangeable calcium in soil of different land use types. The content of exchangeable calcium in different land use types varied greatly, the highest in grain field, with an average content of 1186.66, a range of 167.2-3772.8 mg / kg, a standard deviation of 448.86 mg / kg, and a coefficient of variation of 37.83%; the content of vegetable field was the lowest, with an average of 847.01mg/kg, a range of 347-1342mg / kg, and a standard deviation of 750.63mg/kg, with a coefficient of variation of 88.62%<br>