Evaluation of selected burnt plant residues and mineral fertilizers on soil properties and nutrient uptake and growth parameters of oil palm seedlings

Abstract

Oil palm seeds are difficult to grow due to poor viability; that is why they are raised in nursery. Addition of right and adequate fertilizer is needed to improve soil fertility. Thus, an experiment was conducted in 2022 to compare the effect of empty palm bunch (EPBA) ash, cocoa pod husk ash (CPHA), kola pod husk ash (KPHA), NPK 20:10:10, urea, calcium ammonium nitrate (CAN) and muriate of potash (MOP) fertilizers on soil properties, nutrients uptake and growth parameters of oil palm seedlings in Ondo, southwestern Nigeria. Soil samples were collected from Adeyemi Federal University of Education oil palm plantation. Each of the dried empty palm bunch, kola pod husk and cocoa pod husk was burnt and applied as treatments at the rate of 0, 2, 4 and 6 g 900-g⁻¹ soil while NPK 20:10:10, urea, MOP and CAN fertilizers were individually applied at 2 g 900-g⁻¹ soil. The 16 treatments were replicated four times and  arranged in completely randomized design. A 900 g of soil was put in each poly pot and planted with Tenera variety of oil palm and watered with 50 cl water daily. The native soil used for the experiment was deficient in major nutrients and adequate in minor nutrients. Relative to the control, application of 2, 4 and 6 g ash types significantly increased plant height, number of leaves, root length and plant girth. NPK, recorded the highest increase in plant height. Leaf length and root length were highest with the application of 6 g KPHA. Application of 6 g EPBA recorded the highest biomass, dry and wet weight and seedlings moisture content. Kola pod husk ash applied at 6 g plant⁻¹. Empty palm bunch ash applied at 6 g plant⁻¹ and cocoa pod husk ash applied at 4 g plant⁻¹ compared favourably with mineral fertilizers in raising vigorous and healthy oil palm seedlings.