The experiment started in 1981 on a Pachic Haplumbrept, Urutu soil unit of the Itararé Experimental Station, State of São. Paulo, Brazil. The treatments consisted of three limestones, with different magnesium contents (7.5, 16.0 and 21.7%0 of MgO) applied in amounts corresponding to 0, 3, 6, 9 and 12 t/ha. The three crops were grown in sequence. A significant response to liming was verified, but there was no difference among the three limestones, which were all equally efficient in the neutralization of soil acidity. The amounts of magnesium supplied by the three amendments were sufficient for the crops. Calcium had a positive effect on the potato sizes. A calibration curve for magnesium contents in the soil and relative yields of the three crops is presented.
limine; fimestones; magnesium