摘要
用田间和室内实验,研究了黄棕壤和灰潮土在水旱轮作下的磷吸附特性及其影响的因素。结果表明:供试土壤的吸磷特征与所用等温吸附方程都很吻合,但以Langmuir等温式的吻合性最佳。供试土壤不同轮作处理间磷吸附量的差异随磷加入量的增加而变大。磷吸附X_m值的大小与土壤类型和轮作处理方式有关。向供试土壤加入1000ppm磷时,形成的磷酸铁量在水旱轮作处理间有一定差异,而加入的^(32)P在土壤中主要以磷酸铁存在。土壤经脱无定形铁、铝后,磷吸附X_m值降低,加入的磷转化成磷酸铁的量也减少。供试土壤粘粒的1:1型矿物(高岭石)含量和土壤无定形铁含量与土壤磷吸附X_m值呈正相关。多元线性回归分析证明,土壤无定形铁对土壤磷吸附X_m值的影响比其它因子重要。
Phosphorus sorption characteristics of soil were studied in this paper. Results are as follow:1) The data for phosphate sorption of the tested soils are found to be in close agreement with four sorption isotherms, and the Langmuir equation seems to the data best.2) Among different rotation treatments of the tested soils, the change of the amount of phosphorus adsorbed increased with the amount of phosphate added. The maximum value(403-483) of adsorption (Xm) in yellow brown earth is higher than that ( 329-383 ) in gray Fluvo-aquio soil. When the paddy soil planting rice was changed to the upland soil planting cotton, Xm value was decreased. On the contrary, when the upland soil planting cotton was changed to the paddy soil planting rice.Xm value was increased.3) A model test showed that: (1) Phosphate was added ( 1000μg/g soil ) as the iron phosphates(Fe-P) was formed. Under rice-upland rotation, the change of Fe-P is in accordance with that of Xm value. (2) 48.4--64.7% of total ^(32)P added was turned to Fe-P. (3) When the tested soils were treated with oxalate, Xm value was reduced by 17.7-34.5%, and Fe-P decreased by 19.2--26.4%, the change of aluminum phosphates is less pronounced.4) The content of the Kaolinites in clay and amorphous iron ( FeO) in the tested soils is found to be correlated with the Xm value. Liner regression analysis proved that FeO is an important factor for phosphate sorption.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
1989年第4期346-353,共8页
Journal of Huazhong Agricultural University
基金
国家自然科学基金
关键词
水埋轮作
磷
吸附
土壤
phosphorus sorption of soil
soil
rice-upland rotation
