Over several decades agronomists have developed a mineral nutrition management method for perennial oil crops based on leaf analysis combined with reference field trials. This method has been used in a coconut plantation on the peats of the east coast of Sumatra to optimize mineral nutrition in a very short time, at minimum cost and with maximum reliability, through successive adjustments of the fertilizer schedules. Two reference trials were set up to study a wide range of mineral nutrients assumed to be deficient on this area. Further experiments were set up as new nutritional problems occurred at the plantation, and as soon as the first results were obtained from these two trials. In this way, the iron and copper deficiency problems at the plantation were dealt with satisfactorily taking an experimental approach. New experiments were set up recently to test the hypothesis of a silicon deficiency. The fertilization schedules for the commercial plantation were developed by successive adjustments based on the trial results. Leaf analysis data showed that the coconut palms in the commercial plots always complied with the experimental models. In addition to being rapid and reliable, this method was also cost-effective, especially when larger areas were involved.