Frequencies of applying two fertilizer mixtures to polybag oil-palm seedlings

The effects were examined of applying 114g of two fertilizer mixtures containing N, P, K and Mg in weight ratios of 1:1:1:2 and 1:1:1:1 on growth and mineral composition of oil-palm seedlings grown in polythene bags filled with two different soil types. The potting soils were taken from the top layers of the Orlu and Calabar series, which belong to the order of the Ultisols, and which are the main oil-palm supporting soils in Nigeria. Significant differences did not occur between equal split application of the fertilizer mixture twice at 2 and 8 months, thrice at 2, 5 and 8 months and seven times at 2, 3, 4, 5, 6, 7 and 8 months for oil-palm seedling growth and the percentage N, P, K, Mg and Ca of the leaf, stem and root fractions. Significant differences did not also occur between the two fertilizer mixtures for these parameters. A 1:1:1:1 N, P, K and Mg fertilizer mixture instead of the present 1:1:1:2 ratio in use, applied at 2 and 8 months after sowing, is recommended for both types of oil-palm supporting soils in Nigeria.