Primavesi O, Mello F de, Muraoka T. Comparative study among the chemical factors of the A and B2 horizon of two soils, on the common bean (Phaseolus vulgaris L.) yield . An. Esc. Super. Agr. Luiz de Queiroz. 1987;44(1):741-754. doi:10.1590/S0071-12761987000100038