Journal of Environmental Science and Water Resources ISSN 2277 0704 Vol. 2(5), pp. 150 - 156, June 2013 2013 Wudpecker Journals Soil survey and classification of Ikwuano Abia state Nigeria Godwin .O. Chukwu Department of Soil Science and Meteorology, Michael Okpara University of Agriculture, Umuahia, Abia State, Nigeria. Email: goddychukwu2003@yahoo.com; gochukwu2008@gmail.com. Accepted 03 May 2013 A soil survey aimed at natural soil classification of Ikwuano Local Government Area (LGA) (latitudes 5 0 24 1 to 5 0 30 1 N and longitudes 7 0 32 1 to 7 0 37 1 E) of Abia State, southeast agro-ecological zone of Nigeria, was conducted to provide data for appropriate land use decisions for sustainable agriculture and rural development. A participatory and free survey approaches were adopted. The physiography rises from 30 to 152 m above sea level. The soils are characterized by toposequence and lithosequence, and are classified as Ultisols and Alfisols in the USDA System correlated with Acrisols and Nitisols in the FAO-UNESCO Legend. Three soil series named Orlu, Ahiara and Alagba were delineated. Orlu series is the largest (19,530 ha or 63.0 % of the area) followed by Ahiara series (6,820 ha) and Alagba series (4,650 ha). The soil series are correlated with map units 407, 431 and 12a in FDALR soil maps of Nigeria, to enhance a better understanding and use of the soils in relation to available national soils report. Key words: Soil survey, ultisol, alfisol, acrisol, Ikwuano, south-eastern Nigeria. INTRODUCTION Soil data are primary need necessary as a first step in sustainable land use and soil management decisions. The creation of Abia State in 1991, stimulated efforts to improve agriculture and rural development. Good pedological information is inevitable for these developmental efforts to succeed. Unfortunately, On-farm Adaptive Research (OFAR, 1984; 1985) reported that limited soil resources information militate against agricultural development in the then Umuahia Agricultural zone of Abia State. Most reconnaissance soil survey reports in Nigeria, at agro-ecological zonal levels, states and national levels, provide scanty information about soil resources of rural communities. This is because the scales of such soil surveys (1:1,000,000) are large. For instance, previous soil studies in eastern Nigeria, included soils of Ikwuano LGA within two broad groups: “acid sands” (Doyne et al. 1938) and ferrallitic soils (Jungerius, 1968). Federal Department of Agricultural Land Resources (FDALR, 1985; 1990) also delineated Ikwuano soils within two broad mapping units. Mapping unit 431 is derived from Coastal Plain Sands (FDALR, 1985) while mapping unit 12a is derived from a mixture of Coastal Plain Sands and Sandstone (FDALR, 1990). These mapping units (431 and 12a) are among the soils characterized by Lekwa and Whiteside (1986) and Ohiri et al. (1989) in the defunct Imo State. Therefore, planning for agriculture and rural development in the LGA based on extrapolations from these macro soil studies could lead to faulty results. This challenge was tackled by series of efforts at improving soil resources information at the LGA. For instance, Chukwu and Ifenkwe (2012) discussed biodiversity conservation in Ikwuano in relation to soil mapping units: Ibe, Ibeobo, Obollo and Ariolo. The mapping unit names reflect communities where each major soil predominates. Other technical soil studies in the area include an assessment of land resources problems of Ikwuano for rural development and soil characterization for aquaculture (Chude and Chukwu, 2000). The objectives of the study were: (i) to achieve natural classification of the soils based on the United States Department of Agriculture (USDA) Soil Taxonomy and the Food and Agricultural Organization of the United Nations/the United