ABSTRACT

Characterization, classification and assessment of agricultural potentials of 636.104 km² of land in Bende Local Government Area, Abia State, Nigeria, was conducted using free survey method. Seven (7) mapping units namely BDAES, BDISG, BDBAF, BDFBS, BDLCM, BDUCM and BDALM were delineated. 12 profile pits were dug. Soil samples were collected from the genetic horizons and described following FAO guidelines. Surface soil samples were also collected from the different mapping units for fertility investigation. All the samples were analysed in the laboratory for physical and chemical properties. The soils were classified according to USDA Soil Taxonomy and correlated with World Reference Base (WRB). Land capability classification, Fertility capability classification and Land suitability evaluation were used to assess the potentials of the soils for agriculture. The results showed that the textural class ranged from loamy sand to clay and bulk density was below the critical level (1.75 – 1.85 g kg^-1) soil. pH was generally acidic (4.30 – 5.73). Total nitrogen (0.05 – 0.10 %) and available P (8.62 – 18.03 mgkg^-1) contents were generally low. The organic carbon content of all the mapping units were very low to low (0.58-1.82 %), Exchangeable calcium (Ca²⁺) was very low (0.93 – 6.13 cmolkg^-1), Magnesium (Mg²⁺) was low to moderate (0.47 – 2.55 cmolkg^-1), Sodium (Na⁺) was very low (0.08 – 0.8 cmolkg^-1), Phosphorus (K⁺) was also low (0.03 – 0.27 cmolkg^-1). Base saturation was low to high (30.40 – 86.15 %). The soil Order identified in the area were Alfisols and Ultisols (USDA) and correlated to Luvisols and Acrisols (WRB). The results of the land capability classification (LCC) showed that soils fell into three classes (IIn, IIIn and IVwns) and all were in arable crop production class (I - IV) and the sub classes were on the grounds of nutrient, wetness and soil texture as limitations. Fertility capability classification result indicated that the soils had uniform loamy sand ‘L’ except mapping units BDAES (pedons OW01,02 and 03) and BDFBS (pedon OW08) with ‘clay substrata type’ as represented by ‘C’ The major constraints to crops were acidic reaction, K deficiency and gleying. The results of the land suitability classification showed that soils were currently moderately suitable (S2) and potentially highly suitable (S1) for the various crops (oil palm, cashew, yam, maize, cassava and low land rice). Soil fertility (total N, available P, exchangeable K, pH and Base saturation, organic matter) and soil characteristics (texture) were the major limitation to the soils’ suitability for arable and tree crop production in all the mapping units. Wetness further limits the suitability of alluvial soils of mapping unit BDALM for oil palm, cassava, yam and maize production. Effective management of the soils through liming, application of organic and inorganic manure will reduce the acidity and increase effectiveness of fertilizers and growth of arable and perennial crops in Bende LGA, Abia state, Nigeria.