Resumo

ABREU, C. A.; VAN RAIJ, B.; ABREU, M. F.  e  PAZ GONZALEZ, A.. Evaluation of manganese and iron availability in soils by a modified ion exchange resin method. Rev. Bras. Ciênc. Solo [online]. 2004, vol.28, n.3, pp. 579-584. ISSN 0100-0683.  http://dx.doi.org/10.1590/S0100-06832004000300018.

The objective of this research was to evaluate a modified ion exchange resin method for Mn and Fe extraction from soils. Forty-four soil samples presenting low, medium, and high Mn and medium to high Fe concentrations were used. Maize and soybeans plants were grown as test plants in a pot experiment in a greenhouse. Soil samples were analyzed for Mn and Fe using the modified ion exchange resin, DTPA, AB-DTPA, Mehlich-1, and Mehlich-3 methods. The correlation coefficients between soil Mn and Mn accumulated in the soybean shoot were: ion exchange resin (0.62*), DTPA (0.57*), Mehlich-3 (0.54*), Mehlich-1 (0.51*), and AB-DTPA (0.26). For maize, significant correlation coefficients between soil Mn and plant-Mn were obtained only when low-initial Mn soil samples were considered for all extractants, except for AB-DTPA. For soybeans, the modified ion exchange resin method was as efficient as DTPA, Mehlich-1 and Mehlich-3 for the evaluation of soil Mn availability. None of the methods was efficient for evaluating the soil Fe availability for the 53 day-old maize and soybean plants grown in greenhouse.

Palavras-chave : soil test; extractants; DTPA; AB-DTPA; Mehlich-1; Mehlich-3.