| Abstract: | Abstract The purpose of this article was to compare soil phosphorus (P) extraction by sodium bicarbonate solution (Olsen P) and by ammonium lactate (AL P) and to create a model for prediction of Olsen P using ordinary soil‐fertility control data. The soils data used in this study included Olsen P, pHKCl, pHH2O, organic matter, AL P, and AL K. Soil pHKCl ranged from 3.5 to 8, organic matter up to 5%, AL K up to 400 mg kg?1, and AL P up to 200 mg kg?1. Olsen P and AL P were significantly correlated, and the difference between them was influenced by soil pH. Regression models included all soil data grouped by soil pH range, which significantly decreased the difference between predicted and measured Olsen P. The validation of the model was conducted on new data sets from field fertilization trials. The results show that Olsen P can be related to AL P and used for fertilizer recommendations instead of AL P. |
