Fertility studies were carried out on soils belonging to the "Serie Pinhão" - "Monotípica" from the Pindamonhangaba Experiment Station, Paraíba Valley: The purpose of these studies was to investigate the problem of fertility spots shown by crops grown on these soils and which are attributed to differences in chemical composition between the areas where the plants are normal and those where they are stunted. Soil samples were taken from field areas where corn plants were normal and from spots where the plants were stunted. The influence of adding NPK fertilizers, lime, and micronutrients to both types of soils was studied comparatively in a greenhouse pot test, using wheat as a test plant. Also, a nearly similar fertilizer field trial was carried out including areas of the two types. The results obtained in the experiments indicated that the stunting shown by corn plants growing in certain areas of the planting was due principally to high soil acidity and low percentage base saturation The use of lime and some micronutrients was effective in increasing the yeld NPK fertilizers induced highly significant responses both normal and in areas where the plants were stunted.