SOIL FERTILITY STATUS OF OIL PALM PLANTATIONS IN DELTA NORTH AGRO- ECOLOGICAL ZONE, DELTA STATE, NIGERIA

Abstract

The study was carried out to access the fertility status of soils under oil palm production in Delta North Agro-ecological zone, Delta State. The zone was made up of nine local government areas. Structured questionnaires and oral interview were administered to oil palm farmers in the zone. Six out of the nine local government areas were selected for the study, one oil palm plantation was se- lected from each local government area, they were: Oil Palm Company, Ubulu-Uku, Aniocha South; Bacchor’s Farm Plantation, Ika North-East; Delsu Investment Ltd Oil Palm, Oshimili South; Emelue Farms, Ekwuku Agbor, Ika South; Akpofure Farms, Kwale, Ndokwa West and Emeka Farms, Akwuku-Igbo, Oshimili North. Composite soils were sampled at two levels (top soils 0-15cm and sub soils 16-30cm) from each farm. Data collected were on cultural management practices, soil texture, soil pH, organic matter, total nitrogen, available phosphorus and exchangea- ble bases. The data collected were analyzed using mean and coefficient of variation. The results show that fertilizers were applied without reference to recommended rate, no record of soil testing. The soils were mostly sandy and it decreases with depth while silt and clay content increases with depth. The soils pH was moderate and its fall within the range recommended for tropical crops (5.5 -6.5) except Oil Palm Company where the soil pH is less than 5. The soils organic matter was me- dium except Oil Palm Company and Emelue Farms that had higher at the top and low content at the sub soils. Total nitrogen was low except Oil Palm Company and Emelue Farms that was medi- um at the top soils. Available phosphorus was low to medium, also exchangeable bases were low. Thus, the soils are low in major plant nutrients, the continuous oil palm production without fertiliz- er application will further lead to more soil degradation. For maximum production, fertilizer appli- cation is necessary.