Chemical Dynamic And Bioavailability Of Phosphorus Of Crop's Rhizosphere In Crimson Soil

The thesis quoted the analysis of the inorganic phosphorus graded in limy soil of Jiang pofan's, adopted the net-split-box method to grade the inorganic phosphorus of strongly acidic soil that developed in parent material of Quaternary system. The purpose is to discuss the feasibility of the grade the Inorganic phosphorus in strongly acidic soil and the chemical kinesis and the transformation of the inorganic phosphorus and the relationship of chemical kinesis and bioavailabilility of phosphorus of crop's rhizosphcre in strongly acidic soil, at the same time to study the circumstance of root system of rape and mealie that planted in the strongly acidic soil of different phosphorus treatment in orde to realize the circumstance of soil ohosphorus absorbed of the two oiop.Besides it studyed the isothermal absorption to phosphorus of the soil, in orde to know the circumstance of 36 soil phosphorus absorbcd.The results arc followings: 1 The circumstance of transformation of CaH2PO4 that applied in strongly acidic soil as fo1low~ as time past, the circumstance of falling content of available phosphate could divide two phases: in three hours, the content of available phosphate appeared straight decline,the fixingly ratio was 75.5%;till a year after three hours ,the fixingly ratio was slowly declining. 2 When CaH2PO4 was applied in strongly acidic soil after three hours, the adding contents of each grade of inorganic phosphorus in turns wasFe-P>AL-P>Ca-P>O-P,that evinced phosphorus was applied in strongly acidic soil mostly transformed Fe-P and AL-P at the bcgainirig, subsequently, all of Fe-P,AL-P and Ca-P were declining in different degree as time past,but 0-P was rising, the results evinced that the transformation of phosphorus in strongly acidic soil was mostly transformed to 0-P as timc past. 3 The correspondence of the isothermal absorption to phosphorus of strongly acidic soil with Langmuir equation 37 was notable correlation. The content of thc most absorption was 1560 mg/kg. 4 The correspondence of total priospnorus with available phosphate of each treatment was notable correlation, which evinced there were some arnunts of soil phosphorus as the supplement to available phosphate. S The biomass production of rape and mealie of each treatment were enhanced as the appliment of phosphorus enhanced. 6 The comparision of the soil phosphorus absorbed of the two crops, the total absorption of both were added as the appliment of phosphorus added. Because the biomass production of mealie was bigger than the rape, the total phosphorus absorbed of mealie was bigger than the rape,which evinced the phosphorus requirment of mealie was bigger than the rape in the seedling period. 7 Thc root system shapes of rapc and mcalie had a bigger difference. The root system surface area of unit dry weight of rape was bigger than the mealie, which evinced that the 38 latent ability of phosphorus absorbed of the root system of rape was bigger than the mealie. As t...