Abstract
The land of Akwa Ibom State in a humid tropical area of southern Nigeria, was assessed for yam (Discorea spp) cultivation using the Food and Agriculture Organization (FAO) Land Suitability Evaluation (LSE) system. Twenty nine pedons (about 40% of the state’s land area) identified through field soil survey were evaluated. The results showed that by individual rating, certain land qualities/characteristics:– climate, drainage, soil depth and organic matter content were optimal, others were sub-optimal or grossly inadequate for yam cultivation. However suitability aggregate rating and suitability classification of the 29 pedons showed that about 72% of the area was only marginally suitable, while 28% was not suitable for yam cultivation. The most severely limiting land quality characteristic for yam cultivation in the area was chemical fertility, most importantly, exchangeable potassium (K) and low base saturation. For optimum yam performance, much investment in K fertilizer application and appropriate liming programme to raise the base saturation is highly recommended for the area of study and similar locations elsewhere.