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: Bayelsa State, Nun River floodplain, Soil evaluation factor, Soil fertility assessment, Soil fertility index