Rev. Bras. Ciênc. Solo.2008;32(n.spe):2751-6.
Interpretation of the avalilabre phosphorus by Mehlich-1 and Mehlich-3 extractant solution in soils of the Rio Grande do Sul State, Brazil
01/Dec/2008
DOI: 10.1590/S0100-06832008000700019
Multielement soil extractant solutions are used by several soil testing laboratories to determine the plant availability of several nutrients by the same extractant, to decrease costs and labor. The Mehlich-1 (M1) and Mehlich-3 (M3) solutions are often used for this purpose. In this study, they were used to evaluate soil P availability using 360 soil samples of the State of Rio Grande do Sul (Southern Brazil). The correlation coefficients between the P concentrations extracted by these solutions were strongly associated and highly significant. The P concentrations extracted by the M3 solution were on average 50 % higher than those extracted by M1. The soil clay content affected the P extraction capacity of the M3 solution, requiring an adjustment table for the interpretation of the P value by this method, as proposed here.
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