摘要
实测的等温吸附曲线与常用的Ｆｒｅｕｎｄｌｉｃｈ、Ｌａｎｇｍｕｉｒ及Ｔｅｍｋｉｎ的吸附模式均很吻合，全部相关系数均达极显著水平。由吸附曲线得到的土壤对磷的吸附特性值（ｋ·ｘｍ）差异较大，东部地区较西部高，覆盖黑垆土＞黄绵土＞黑麻土＞灌漠土。影响土壤吸磷的因素主要是土壤有机质含量和阳离子代换量（ＣＥＣ），有机质含量越高，土壤对磷的吸附结合能越小，而吸磷量增加；土壤吸附磷的解吸曲线不同层次与土壤吸附磷的结合方式不同有关。水溶性磷加入土壤后，首先形成二钙磷，其次是Ａｌ－Ｐ，再次是八钙磷。
P sorption isotherms obtained in this study were fit in very well with the Freundlich, Langmuir and Temkin equations. Phosphorus sorptivity values (k· x m ) obtained from the Langmuir equation were very much different and regularly increasing from west to east of Gansu. The order of the sorptivity values based on soil nature was dark Lu soil>Loessial soil> Heima soil> Irrigated desert soil. The main factors affecting P sorption by soil were soil organic matter content and CEC. The higher the O.M. content, the lower the bonding energy of soil, while the more HPO 2- 4 was absorbed by soil. P desorption isotherms showed different stages of desorption, which related to the P bonding energy by soil. After being added to soil, the soluble phosphate turned into Ca 2-P at first, then Al-P, Ca 8-P, and finally formed insoluble phosphate.
出处
《西北农业学报》
CAS
CSCD
1997年第2期7-12,共6页
Acta Agriculturae Boreali-occidentalis Sinica
关键词
土壤
磷吸附
磷解吸
吸附特性值
甘肃
Soils
Phosphorus sorption
Phosphorus desorption
Sorptivity value
Gansu
