AbstractPhosphorus was extracted from 30 alkaline soils from western Minnesota using the Olsen NaHCO₃, the Soltanpour AB‐DTPA, Mehlich 2, Mehlich 3, Bray‐1, and resin methods. Values from the first six methods were compared to resin extractable phosphorus.The NaHCO₃‐P values for 30 soils were most closely related to resin extractable‐P values with r ‐ 0.943, followed by the AB‐DTPA with r ‐ 0.889, and Mehlich 3 with r ‐ 0.809. Bray‐1 values from three different soil‐to‐solution ratios were less closely related to resin P. The correlation coefficient between Olsen NaHCO₃‐P and Bray‐1 was r ‐ 0.693 for all 30 soils.Soils were divided on the basis of their reaction to dropwise addition of 10% HC1. Violently effervescent samples (n‐15), with one exception, were found to be those soils in the study group with calcium carbonate equivalent (CCE) ranging from 7 to 62 percent. Non‐violently effervescing soils (n‐15) were found to have CCE of less than 7 percent. The elimination of the violently effervescing, high CCE soils from the study group resulted in r values greater than 0.9 for all methods when compared to resin P. Improvement in the relationships between the acid extractants (Bray‐1 and Mehlich 2 and 3) with resin P was attributed to elimination of high CCE soils. Improvement in the relationship between AB‐DTPA and resin P was attributed to the removal of high clay soils that, by chance, also contained high CCE. Olsen NaHCO₃ and Bray‐1 (1:10 soil‐to‐solution ratio) values were closely related (r‐0.973) for the non‐violently effervescing (low CCE) soils.Only the NaHCO₃ values were closely related to resin P for the 15 high calcium carbonate soils, although AB‐DTPA values were closely related to resin P when the high clay (> 35%) soils were removed.