Effect of Oil Palm Bunch Refuse Ash in Sustainable Production of Egusi-Melon (Colocynthis citrullus) in an Ultisol

Soil fertility management is a major challenge in high humid tropical regions of Nigeria. Field experiment were conducted at National Cereals Research Institute, Uyo Out-Station 2011 and 2012 to investigate the response egusi melon (Colocynthis citrullus) different rates OBRA (1,2,3,4, 5 6 t/ha) 200kg/haNPK as recommended rate inorganic fertilizer for study area. The was laid out randomized complete block design, replicated three times. Data collected on growth yield egusi-melon subjected analysis variance. Significant means compared using least significant difference 5% probability level. Application t/ha produced seed 243.40 253.10 kg/ha 2012. Treatment 200kg/ha NPK 193.60 201.75 respectively. control (no soil amendment) 125.33 128.11 2012, Comparing with (200kg/ha), treatment 6t/ha had 21 20% greater than NPK. chemical properties harvest indicated pH (7.80 7.90) organic matter (3.50 3.55%) respectively low (5.00 4.90) (2.08 20.1%) observed treatment. therefore concluded that application 4t/h could be cheap alternative sustainable production acid coastal plain soils