Mature oil palms growing on a Lancang series soil were supplied with ammonium sulphate, urea or urea plus K (4.8 kg potassium sulphate). Application rates were 0.4 or 0.8 kg N per palm per year. The fertilizers were applied broadcast over a weeded circle around the palm, twice or 4 times each year, or broadcast overall twice a year. Control plants received no fertilizer. In Apr. 1991 (7 years after treatments commenced), leaf samples were taken from 8 palms in each treatment. Leaf S concentration varied from 0.16 to 0.30% in the various treatments, but the mean values for each different level of S application (0, 0.458, 0.864 or 0.916 kg S palm-1 year-1) did not vary significantly (0.206-0.212%). No S deficiency symptoms were observed in any of the treatments, including controls.