Characteristics, classification, and agricultural potential of some Niger Delta soils in Nigeria

Nine pedons representing the major soils of an 80,000 ha area in Yenagoa, Niger Delta, Nigeria, were classified and evaluated for maize, plantain and oil palm cultivation. The soils were identified as low activity clay (LAC) Ultisols (Kanhapludult and Kandiudult) or Acrisols (FAO, UNESCO) with hydromorphism reaching the A-horizon in most cases. They were mainly derived from alluvial materials. The presence of an argillic B-horizon in all the pedons indicated that the depositions were not recent. Most of the soils were sandy at he top but clayey in the subsoils although a few have either sandy or clayey texture throughout the profile. Organic matter content in the A-horizon was 2.30-4.50%. The pH was between strongly acidic (3.5) to slightly acidic (5.0). The CEC in the B-horizon was low (<24 cmol kg-1) in the sandy soils and moderate (>24 cmol kg-1) in the clayey soils. The exchange complex was dominated by Ca(2-17 cmol kg-1), followed by Mg (1-8 cmol kg-1), while K was low (0.07-0.22 cmol kg-1) to fairly high (>0.66 cmol kg-1). The base saturation was just moderate (50-92%). The soils were marginally suitable (S3) for maize, with about 20% of the area not suitable (Nl) presently. The main constraints to arable cultivation were heavy rainfall, imperfect poor drainage, and low base saturation. They are moderately suitable (S2) for plantain due to low base saturation, short dry season, and unfavorable texture which was light in some and too heavy in others. For oil palm, the soils were moderately (S2) to highly (S1) suitable, though the short dry season, low base saturation and poor drainage could pose as limitations. Obviously, with good drainage and proper fertility management high yields of maize, plantain and oil palm could be obtained on these soils. Such studies should be made to cover the entire Niger Delta in order to provide data to justify The preservation of all prime agricultural soils in the area from being lost to the oil industry.