Comparing measures for determination of phosphorus saturation as a method to estimate dissolved P in soil solution

In response to concerns over the translocation of P from soils P-sensitive water bodies, there is high demand for developing simple indicators evaluating a soil’s risk releasing into solution. Many studies have shown that degree soil phosphorus saturation (DPS), calculated as ratio concentration sorption capacity (PSC), good predictor in this study we compared four different DPS indices how well they predicted dissolved following extraction with either 0.01 M CaCl2 (PCaCl2) solution or deionized (PW). The first two were extractable Al and Fe using acid ammonium oxalate (AlOX + FeOX) lactate solutions (AlAL FeAL). second Olsen-extractable AL-extractable estimated single point index (PSI). On subset 11 soils, methods estimating PSC fitted Langmuir maximum (Smax) data complete isotherms. Both PSI correlated Smax hence regarded estimates capacity. Conversely, FeAL) was not significantly Smax. together PAL POls PCaCl2 PW best, whereas least. We did find notable improvements regression models when added explanatory variable (clay content, pH total carbon) models. Our results show multiple measures provide similar predictions soi?s potential This provides flexibility are identify leaching prone hotspots.