CHANGES IN SOLUBLE AND EQUILIBRIUM PHOSPHATE CONCENTRATION IN SELECTED SOILS FROM ITALY

Citation
R. Indiati et An. Sharpley, CHANGES IN SOLUBLE AND EQUILIBRIUM PHOSPHATE CONCENTRATION IN SELECTED SOILS FROM ITALY, Communications in soil science and plant analysis, 29(15-16), 1998, pp. 2429-2440
Citations number
17
Categorie Soggetti
Agriculture Soil Science","Plant Sciences",Agriculture,"Chemistry Analytical
ISSN journal
00103624
Volume
29
Issue
15-16
Year of publication
1998
Pages
2429 - 2440
Database
ISI
SICI code
0010-3624(1998)29:15-16<2429:CISAEP>2.0.ZU;2-K
Abstract
Soil phosphate in solution (Psol) and equilibrium P concentration (EPC o) are important soil P parameters both for agronomical and environmen tal purposes. Solution P is the main source from which plant roots ads orb P, whereas EPCo give information about the amount and direction of changes between soluble and particulate P that occur during transport of sediment in stream flow. Changes in Psol and EPCo with soil extrac table P (Mehlich 3-P and Olsen P) were determined following equilibrat ion of 13 Italian soils with five rates of fertilizer P (0 to 100 mg k g(-1)). The slope of the regression equation (Y=a+bX) for the relation ships between Psol and EPCo (Y), and soil extractable P (X) decreased with increasing soil P sorption. Furthermore, at the same level of Meh lich 3 and Olsen P, higher sorbing P soils had lower values of Psol an d EPCo. As a result, changes in Psol and EPCo per unit increase of soi l extractable P were closely related (R-2 of 0.86 to 0.93) to soil P S orption Index(SI). Equilibrium P Concentration could be estimated from soil solution P for the studied soils.