Global Journal of Agricultural Research, 12, (1), 1-15, 2024 Print ISSN: 2053-5805(Print), Online ISSN: 2053-5813(Online) Website: https://www.eajournals.org/ Publication of the European Centre for Research Training and Development -UK 1 Fertility Assessment of Nun River Floodplain Soils in Bayelsa State, Southern Nigeria for Agricultural Productivity Achimota A. Dickson*, Payou T. Ogboin, Williams P Agbai & Maureen D. Tobin-West *Corresponding author: achimotadickson@ndu.edu.ng, Orchid.org/0000-0003-0126-8431 doi: https://doi.org/10.37745/gjar.2013/vol12n1115 Published January 09 2023 Citation: Dickson A.A., Ogboin P.T., Agbai W.P. and Tobin-West M.D. (2024) Fertility Assessment of Nun River Floodplain Soils in Bayelsa State, Southern Nigeria for Agricultural Productivity, Global Journal of Agricultural Research, 12, (1), 1-15 ABSTRACT: Following massive crude oil exploitation in Bayelsa State, arable land is shrinking and a food crisis, looming. To stop this trend, information on soil fertility status and management strategies becomes important for policy development. This paper assesses fertility status of the Nun River floodplain soils in Bayelsa State using newly developed indices for sustainable agricultural productivity and food security. Nun River plain alluvial soils of different landforms were collected from the genetic horizons of nine profiles, and analysed for physicochemical characteristics and soil fertility assessed using soil fertility index. (SFI) and soil evaluation factor (SEF). ). Silt-sized particles dominated Odi (ODI), Koroama (KRM) and Niger Delta University (NDU 1) soils, except in NDU2 and NDU3, pH was moderate to slightly acidic (5.64–6.30), available P, low to high (0.6–22 mg/kg), organic C (0.31–5.35%), and total nitrogen (0.01– 0.45%) low to high while calcium dominated the exchange complex. Correlation between Organic matter and total N (r = 0.366, p ‹ 0.001) and available P (r = - 0.310, p ‹ 0.01) was highly positively, suggesting that organic matter dictates availability of N and P. The SFI values were higher (p ‹0.05) than SEF except in NUD2 and NDU3, pH, organic matter and available phosphorus contributing more. Of paramount importance is conservation of organic matter as the accumulation of biomass greatly improved physical properties and fertility of the soil. KEYWORDS: Soil fertility assessment, Soil evaluation factor, Soil fertility index, Nun River floodplain, Bayelsa State INTRODUCTION Tropical forests are one of the most productive of all terrestrial ecosystems and play a functional role in maintaining biodiversity, improving the global climate and conserving soil (ITTO, 2020). But, in the Niger Delta region of Nigeria, the amount of land available for agricultural production continue declining following the discovery and exploitation of crude oil (Dickson and Dadiovei, 2010). With increasing oil revenues, little or no attention was paid to protecting land for agricultural production. Oil companies went about their business with little or no effort. Given the degradation of land for agricultural production, exploration and exploitation activities have neither taken this into account nor protected the limited well-drained land available for agriculture (UNDP, 2006). With the increasing loss of agricultural land to the oil industry, food crises have