Application of Geophysical Techniques in Investigating Soil Characteristics for Oil Palm Plantation Suitability in Iyede, Delta State, Nigeria

Abstract

Ten Vertical Electrical Soundings (VES) and the Schlumberger simple array technique were used to analysis the subsurface changeable conditions of the oil palm plantation at Iyede, Delta State, Nigeria. Low resistivity values (34.7–123.0 Ωm) for VES 2, 4, 6, and 7 were found using the ABEM SAS 1000 Terrameter. These results indicate a variable high moisture level, loamy soil content, fine soil texture, and soil rich in nutrients that are favorable for oil palm germination and growth in the region. The formation of coarse-medium soils were indicated by areas with sporadic greater resistivity surpassing 140 Ωm (142.6-391.6 Ωm), which may have hampered root penetration and water retention for VES 1, 3, 5, 8, 9, and 10. Analysis of the Iyede soils revealed a pH range from mildly acidic (6.8) to acidic (4.7) and consistently low nitrogen content (0.16% to 0.40%). Potassium levels varied between 0.11 to 0.61 mg/kg, while available phosphorus varied significantly from 10.81 mg/kg to 46.89 mg/kg. Overall, potassium content were low (absolutely lesser than 78 mg/kg) across all locations, below the threshold required for optimal oil palm growth. Magnesium was not a limiting factor for oil palm development at the site studied, as exchangeable magnesium levels were consistently high (36–108 mg/kg). Plant growth was positively influenced by calcium (3.45 to 8.20 mg/kg) and sodium (0.42 to 1.92 mg/kg). The use of appropriate fertilizers can further support healthy palm oil development and enhance fruit production in some oil palm farms in the study area.