Properties and land suitability evaluation of selected soils of Umueje, south- east Nigeria for yam (Discorea spp.) and oil palm (Elaeis guinensis) cultivation

The study was conducted to characterize and assess land suitability of selected soils of Umueje, Ayamelum LGA, Anambra State Nigeria with a view to making adequate management practices for sustainable production of yam (Discorea spp.) and oil palm (Elaeis guinensis) in the area. Three mapping units (ANU1, ANU2 and ANU3) were delineated using the transect method with several auger investigations. Five representative profile pits were dug and described in situ for morphological properties. Soil samples were collected from the identified horizons and analyzed for physical and chemical properties. The results showed that ANU1, ANU2 and ANU3 were imperfectly, moderately and well drained respectively. Textural classes observed were sandy loam, loam sandy clay loam, clay loam and clay with irregular distribution of soil separates down the pedal depths. Bulk density was below the critical limit (1.75–1.85kgm-3). The soils were strongly acid (5.08–5.95) with moderately low values of total nitrogen (0.06 – 0.11%), available phosphorus (10.65 – 12.83mgkg-1) and exchangeable potassium (0.14 – 0.21cmolkg-1) but high in organic matter (1.44 – 2.24%). Base saturation was generally high (67.72 – 72.97%) and cation exchange capacity was low (6.14 – 7.51cmolkg-1). Aggregate suitability evaluation showed that optimal performance of ANU1 was constrained by poorly drained condition and thus, currently marginally suitable (S3) for the cultivation of yam and oil palm. The current suitability of ANU2 was moderate (S2) for the cultivation of yam and oil palm while ANU3 was moderate (S2) for yam but marginal (S3) for oil palm cultivation with fertility (f) as limitations. Adequate soil management practices such as drainage, liming, organic manuring and use of fertilizers should be encouraged for optimal production of the selected crops.