Malaysian soils, like most tropical soils, are highly weathered, acidic and inherently low in phosphorus (P) but with high P-fi xing capacities. High rates of P fertilizers are required to overcome the P-fi xation, mainly due to high Al and Fe oxides and hydroxides in the clay fraction (Ng, 1986). P is one of the major plant nutrients required for good growth and production of oil palm. Studies have shown that P has synergistic effects with nitrogen (N) and potassium (K) on oil palm yield. In oil palm fertilizer trials in Peninsular Malaysia, testing high rates of fertilizers, large responses to N and K fertilizers were obtained but the full responses were only obtained with adequate P fertilization (Foster et al., 1988). This article will serve as a guide to the importance of applying the optimum rates of P fertilizer together with N and K fertilizers and the technique used to maximize the potential of the P fertilizer to increase FFB yield in mature (7-20 years old) oil palm replants, particularly on inland and coastal soils of Malaysia.
Main Research: Dr. Zin Zawawi Zakaria