CHARACTERIZATION AND CLASSIFICATION OF SOME FLOOD PLAIN SOILS AT WEPPA, EDO STATE, NIGERIA FOR SUSTAINABLE AGRICULTURAL PRODUCTIVITY

Abstract

The need to increase agricultural production as a result of increasing population pressure on land resources, competitive land use and declining agricultural productivity of upland soils has brought about increased utilization of the flood plains to meet man’s needs for food and fibre. Judicious use of land resources requires basic knowledge of the soil characteristics. The objectives of this study were to characterize and classify some flood plains soils in Southern Nigeria and to identify soil management options for sustainable agricultural productivity. A detailed soil survey was carried out at Weppa, Edo State using the rigid grid method and six mapping units were identified.  A soil profile pit was dug on each mapping unit and described in detail. Samples were taken from each genetic horizon of these profiles and subjected to laboratory analyses using standard procedures. The soils were characterized for their morphological, physical, chemical, properties and weathering indices. Soil classification was carried out using local and international classification systems.

 All profiles were mottled showing impeded drainage. The distribution of texture, colour and organic carbon were irregular in most profiles. The soil weathering indices such as amorphous to crystalline iron ratio, clay co-migration, Silt/Clay ratio and CEC/Clay revealed that the soils were young. There was significant (p <0.01) negative correlation between calcium and exchangeable sodium percentage (r= -.674**); calcium and hydrogen (r= -.503**) and between aluminum and base saturation (r= -.449*) while there were significant positive correlation (p <0.01) between crystalline iron and amorphous iron (r= .506**); amorphous iron and iron ratio (r =. 580**).The soils were classified at series level as Edozhigi, Indaloke, Illah, Agaie, Badeggi and Mawogi series belonging to the Inceptisols and Entisols in the soil Taxonomy. Low weathering, nutrient status and moisture availability in these soils could sustain reasonable agricultural productivity. However, they require careful management to ameliorate acidity, nutrient deficiencies and poor drainage conditions.