Bowman-Cole石灰性土壤有机磷分组法的改进

本文研究了Bowman-Cole土壤有机磷分组法应用于石灰性土壤存在的若干问题,并提出了改进法。改进法的四组土壤有机磷(P0)的分组为:在氯仿预处理土样后用0.5molL-1NaHCO3浸提活性P0;然后,先用0.05molL-1NaOH、后用1molL-1H2SO4处理残余土样浸提中度活性P0,0.05molL-1NaOH提取的无机磷和1molL-1H2SO4提取的有机磷属于中度活性P0;在氯仿和0.5molL-1NaHCO3处理后,用0.05molL-1NaOH浸提稳定性P0,把浸提液的酸度调至pH3.00时,上清液中的有机磷为中度稳定性P0,而沉淀中的有机磷为高稳性P0。结果表明,改进法能更好地区分具有不同矿化率的有机磷化合物,例如,核酸、甘油磷酸、植酸钙、肌醇三磷酸铁、植酸铁等。改进法增加了超声波处理,使震荡时间也明显缩短。因此,石灰性土壤有机磷分组的改进法比Bowman-Cole法更理想。

A Modification of Bowmen- Cole'''' Fractionation Method of Soil Organic Phosphorus

Some problems on Bowmen-Cole' fractionation method of organic phosphorus (P_0) in calcareous soil were studied. A modified fractionation scheme was proposed: The labile P_0 in which contained the microbial P_0 was extracted by fumigation of soil with chloroform pretreatment.The extracting agent concentration of NaOH for extracting stable P_0 was reduced to 0.05 mol L~(-1) NaON as suitable; when the extract by 0.05 mol L~(-1) NaON in which contained the stable P_0 was adjusted to pH=3.00, the supernatant solution contained moderately stable P_0, while the precipitate contained highly stable P_0.Moreover, the moderately labile P_0 was changed to be extracted by 1mol L~(-1) H_2SO_4 from the residual after pretreatment with 0.05mol L~(-1) NaOH to remove the stable P_0, and the inorganic P contained in the 0.05 mol L~(-1) NaOH belongs in moderately labile P_0 . The result of this study shows, the organic phosphorus compounds with different mineralization rate, such as nucleic acid, phospho-glycerol, calcium phytate, iron of inositol triphosphate and iron phytate, were more reasonably separated by the modified method.The shaking time for extracting soil organic phosphorus was shortened by ultrasonic treatment.