Estudos sôbre a fertilidade dos solos do cerrado: I. efeito da calagem na disponibilidade do fósforo (Nota prévia)

Abstract

The method of isotopic dilution was successfully used to study the influence of limestone in the availability of native phosphorus. A values were determined by a simplified technique using samples of cerrado soils previously submitted in the field to the treatment with different amounts of limestone. It has been found out: (1) the three types of cerrado soils had different amounts of available phosphorus; (2) liming increased linearly the A values in the case of two of the soils under study; in the third one, howerer, the response was linear also up to a point wherefrom a further increase in the aumount of limestone applied caused a significant drop in available phosphorus.