Remaining Phosphorus Estimate Through Multiple Regression Analysis

摘要

The remaining phosphorus (P_(rem)), P concentration that remains in solution after shaking soil with 0.01 mol L~(-1) CaCl_2 containing 60 μg mL~(-1) P, is a very useful index for studies related to the chemistry of variable charge soils. Although the P_(rem) determination is a simple procedure, the possibility of estimating accurate values of this index from easily and/or routinely determined soil properties can be very useful for practical purposes. The present research evaluated the P_(rem) estimation through multiple regression analysis in which routinely determined soil chemical data, soil clay content and soil pH measured in 1 mol L~(-1) NaF (pH_(NaF)) figured as P_(rem) predictor variables. The P_(rem) can be estimated with acceptable accuracy using the above-mentioned approach, and pH_(NaF) not only substitutes for clay content as a predictor variable but also confers more accuracy to the P_(rem) estimates.