Resumen

PEREZ, Micaela et al. Evaluation of methods for determining soil phosphorus extractable in the semiarid pampean region. Cienc. suelo [online]. 2019, vol.37, n.1, pp.11-20. ISSN 1850-2067.

Two widely used methods for soil phosphorus (P) determination are Bray Kurtz 1 (B & K) and Olsen. Argentine regulations (IRAM-SAGyP) for the analysis of extractable P in soils for agricultural diagnostic purposes define that B & K is suitable in slightly acid, non-calcareous and non allophanic soils, while Olsen is best suited for all soils. In the semi-arid pampean region, P extraction was historically carried out by means of B & K, and even today, this test is used, although its generalized use in all soils is under discussion. The objective of this study was to evaluate the relationship of extractable P using B & K and Olsen in different soils of the semi-arid pampean region. The samples were classified considering their pH value, Fieldes Perrott test reaction and calcareous. In all cases, a significant difference was observed between extractable P determined by B & K and Olsen. A significant linear relationship was observed between both P tests methods; although the coefficients of determination (R²) ranged from 0,12 to 0,79. Based on the results obtained, the use of regression equations was not recommended to convert the results of P from one soil test method to the other in the region under study. Therefore, the P test method to use should be defined based on the diagnostic method used for fertilization recommendation. In those cases where the method of diagnosis is not indicated, the national regulation will define the P extraction method to be used according to the pH of the soil, Fieldes Perrott test reaction and calcareous.

Palabras clave : Bray Kurtz 1; Olsen; soil pH; Fieldes Perrott test and calcareous.