Data of a continuous fertilization yield trial were analysed in two locations in 1972-73, to study the effect of continuous annual application of ammonium sul-phate, simple superphosphate and potassium chloride on yield and composition of kernels. The foliar chemical analysis was utilized to determine the plant response to the fertilizer application. Data showed a significant effect of local conditions on the yield and composition of plant material. Ammonium sulphate and superphosphate increased yield in both locations whereas potassium chloride was a factor only in Mococa. Phosphate application was the main factor to explain yield in any condition. In Mococa the nitrogen dosage, the contents of N, S, P, Mn, Cu, Zn in the leaf +4 and yield were positively correlated with protein and negatively associated with starch percentage of the seed. All the above cited nutrients increased with ammonium sulphate application. Both phosphate fertilizer and P in leaves correlated positively with seed oil content. Potassium fertilizer and K in leaves were positively correlated with percent oil and negatively associated with linoleic acid. Total oil content and linoleic acid showed negative correlation. There was a tendency for potassium fertilizer decrease starch in the grain. This was evidenced by negative correlation between K and CI in the leaves and kernel starch. Both locations showed significant correlation between same leaf and grain elements. Sulphur and N, Mo-Fe were positive whereas Pe-P and Al-P showed negative values. The amino acids glycine, lysine, and tryptophan in the protein fraction of the seed were negatively associated with crude protein content in Mococa, while there was an increase of proline followed by reduction of phenylalanine and arginine in Campinas. Yield and P in the leaf correlated positively with oil content in both places. Both oil content and fatty acid composition were affected by location. High oil content seeds revealed higher levels of oleic, palmitic, stearic, and lower linoleic acid content.