SOIL CHARACTERIZATION AND LAND SUITABILITY EVALUATION OF ANUKA FARMLAND IN NSUKKA LOCAL GOVERNMENT AREA OF ENUGU STATE, NIGERIA

Thesis Abstract

The land at Anuka, Nsukka Local Government Area of Enugu State in Southeastern Nigeria,under the sub-humid tropical climate was evaluated for maize (Zea mays), cassava (Manihotesculenta), yam (Dioscorea spp.) and oil palm (Elaeis guineensis) cultivation. Data wereobtained by field study and laboratory analyses. Six pedons were dug and described two pedonseach for maize and oil palm fields, and one each for yam and cassava fields. These pedons weredug to represent sampling units. Auger samples were also purposefully collected from thesampling units at depths 0 – 20cm and 20 – 40cm. This was to investigate the nutrient spread inthe area. Soil samples from the pedogenetic horizons of the pedons were collected after profiledescription, processed and analyzed. The pedons were designated P01 = cassava field, P02 andP03 = maize fields, P04 = yam field, and P05 and P06 = oil palm fields. The textural classes ofthe soils included sandy clay loam, sandy loam, sandy clay, loam, clay loam and clay, but thedominant textural class is sandy clay loam. The overall results showed that the soils are acidic;the phosphorus content is generally low; organic matter ranged from 0.42 – 4.31 %, decreasingdown the profile depth and is medium (>2.0 %) for epipedons. Exchangeable bases are generallylow low exchangeable Ca (1), very low exchangeable Na (Total nitrogen content is moderately low to very low (0.042 % < N < 0.196 %). The soils met thecriteria for classification as Typic Dystrustults (P01, P03, P04, P05 and P06) and AquicArgiustults (P02) (Soil Taxonomy), correlated to Acrisols (FAO/UNESCO). The results showedthat although climate and topography are optimum or near optimum, there was no current highlysuitable (S1) soil unit for maize, cassava and yam cultivation by both parametric and nonparametricmethods of suitability evaluation. However, soil units P01 and P02 showed actual andpotential S1 for oil palm production in the study area. None of the sampling units showed highsuitability for its current utilization type. The severe constraints to crop cultivation in the area aregenerally low fertility for all soil units; wetness for soil unit P02 and adverse soil physicalcharacteristic for soil unit P04. Application of organic manure, use of balanced fertilizer anddrainage management practices are necessary for maximum productivity of Anuka soils for theevaluated crops.