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Arai, Y., and D.L. Sparks. Phosphorus fraction dynamics in amended soils. SSSA Annual Meeting Abstracts,Oct. 31-Nov. 4, 1999 Salt Lake City, Utah. p. 212.


Phosphorus (P) fraction dynamics on high P (NH4ox P >600mg kg-1) Southern Delaware soils (0-30 cm) was investigated. Short term (24h) P desorption (0.1M NaCl at soil pH) using a stirred-flow method on non-treated and treated (NH4Cl, NH4Cl + NH4F extraction) soils showed that P release was significantly reduced in following treatment order (NH4Cl > NH4Cl+NH4F > NH4Cl + NH4ox). More than 65% of labile P in the high P soils was originated from NH4ox and NH4F extractable P fractions. Long term (30d) P desorption, using a dilution method (0.1N NaCl at soil pH) coupled with sequential inorganic P extraction (NH4Cl, NH4F, NH4ox, NaOH, NaCDT, and H2SO4) on 15d and 30d desorption samples also showed a high correlation between labile P and NH4ox + NH4F extractable P. P mineralogical characterization of the P treated soils was also investigated using ex-situ spectroscopic techniques (FTIR and EDX).