Evaluation of Fertility Status of Proposed Site for St. Gabriel Coconut Plantation and Refinery, Akwa Ibom State, Nigeria

Abstract

Information on the fertility status of the soils on which coconuts are grown and possible fertilizer recommendation is not common. Since coconut yield is generally related to the fertility status of the soil, a study was conducted to evaluate the fertility status of proposed sites for establishment of coconut plantation by the Akwa Ibom State Government. The soils were sampled at four depths 0 “ 15 cm, 15 “ 30 cm, 30 “ 60 cm and 60 “ 120 cm. The soil samples collected were subjected to physical and chemical analysis using standard analytical procedures. The soil physical properties do not constitute any major limitation to good coconut growth and yield. The soils at St Gabriel Coconut plantation texture was dominated by the sand fraction which accounted for an average 889 to 914 gkg¹. The sandy nature of the soils makes the soils very susceptible to water erosion, low cation exchange capacity (CEC) and low buffering capacity resulting in low fertility status, multiple nutrient deficiency and nutrient imbalance. The water table was high which was responsible for poorly drainage of the area leading to waterlogging of some location within the plantation site. The soil pH both in water and potassium chloride revealed that the soil acidity ranged from slightly acidic to strongly acidic which highly favour coconut palms cultivation. The exchangeable cations capacities were relatively very low. The values all fall below the critical limits for fertile soils, which may adversely affects optimum growth and development of the coconut palms.The values of soil fertility parameters were predominately low, indicating decline of soil physical and chemical properties due to soil degradation. The evaluation showed that the soils suffer from multi-nutrient deficiency. Nutrient levels of the soils are low to very low, and will not support good coconut growth and yield. Liming to improve the exchangeable basic cations and pH of the soils is recommended. Use of rock phosphate is also recommended for raising the levels of both phosphorus and some basic cations.