CHAPTER ONE
INTRODUCTION
Wetland soils, otherwise designated hydromorphic soils, may be defined as soils whose properties are influenced by the presence, either seasonally or perennially of standing water within their profiles (Eshett, John, Omueti and Juo 1986),also considered soils, which are water saturated during most of the months (Onyekwere,  Akpan-Idiok, Amalu, Asawalam and Eze, 2001).      Wetland soils occur commonly in swamps, floodplains, inland valleys, and other areas of low topography and are usually underlain by impervious parent material which prevents or retards infiltration of water emanating from rainfall, irrigation, river inundation, surface run-off or seepage from surrounding highlands.
Wetland cultivation is now being emphasized (Okusami and Rust, 1992; Ogban and Babalola, 2003, 2009) to supplement the uplands where soil productivity and crop yields have declined due to severe accelerated erosion and degradation (Lal, 1988), accentuated by farmers mining the physical, chemical and biological fertility of their soils (IITA, 1990).
The wetlands are reputed to produce over 90% of crops grown on uplands, (Ogban, Effiong, Obi and Ibia,  2011) and are therefore as important as the upland farmlands in that they can be used in the wet season (mainly rice), dry season (cassava, yams, cocoyams, tomato and vegetables), and all year round for tree crop production. The wetlands thus forms an important component of the ecosystem in the State, therefore justifying the need to study them including their natural fertility with a view to recommending appropriate management options for crop production and putting them to other sustainable uses. Their fertility is important as nutrient depletion is one of the major constraints in tropical and sub-Saharan soils and P is one of the nutrients of concern or interest in agro-ecologies.