Discussions on Medium for Fixing Phosphorus in Calcareous Soils
Lu Jialong Li Zuyin(.Soil and Agrochemistr y Department)
Eight main behaviours (CaCO3, 0.01 mm physical claysj 0.001 mm clays$ free Fe2O3, pH, organic matter} available phosphorus} and total phosphorus)of 39 calcareous soil samples taken from 7 provinces (Autonomous Regions)in North China were analysed. Also,phosphorous adsorption coefficient (PAG) , percentage of fixed phosphorus and phosphate fertilizer index (PFI) were determined in this test. Correlation analysis, path analysis and multiple regression analysis showed that the medium for fixing phosphorus in calcareous soils was not CaCO3, but physical clays less than 0.01 mm.