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A study was conducted in April 2006 to determine the phosphate relationship in acid sulphate soils of Mbiabet Swamp Rice farm in Akwa Ibom State, Nigeria. Soil samples were collected in the order of 0 -1, 1 -2, 2 -5, 5 -8, 8 -10 and 10 -15cm soil depths. Treatments consisted of potassium dihydrogen phosphate added to the swamp mud, cat-clay, and mud-clay in equal doses of 122 kg/ha P 2 0 5 , fitted into Latin square of 36 x 5 m swamp, except for the control plots. Limestone (CaC0 3 ) was applied to both fertilized and unfertilized plots at the rate of 50 kg/ha to reduce the activity of alumimium. The distribution of phosphate in the top 10 cm of unfertilized plots at the fresh and dried mud showed that the bulk of the total phosphorus was in the organic and occluded forms. There was no saloid-bound phosphorus present in either the fresh or dried mud. The fixation of phosphorus was rapid, reaching the equilibrium within 50 -75 hours. Fresh mud (except cat-clay) absorbed more phosphate than did dried mud and nearly 60 percent of the absorption took place within 6 hours. The soluble phosphate applied as solution to columns of air-dried swamp mud showed a decrease within 6 months, but calcium and organic phosphate increased. Saloid-bound phosphate with the water-logged cat-clay decreased considerably. The soils have great opportunities in rice production when given proper soil management.

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Investigation of the chemical properties of the coastal plain soils treated with NPK 20:10:10 fertilizer (NPK) at the rate of 0,60, 90 and 120kg ha -1 and observed at intervals of 3,6,9 and 12 months was carried out from March 2009 to 2010 at Akpabuyo, Cross River State, Nigeria. The experiment comprises of four fertilizer rates and four management intervals fitted into a Latin square design. The soils pH value increased consistently from 3 to 12months. Mean values of organic matter decreased with increase in profile depth from 2.12-1.34g kg -1 . The distribution of N from the top soil down the profile increased consistently from 3 to 12 months. The mean value of N from the top soil was 0.82%. Exceeding 0.2%, the critical value and was more than the mean values obtained in the sub-surface soil. The mean value of P (33 mgkg -1 ) during the 9 months interval was significantly (P<0.05) higher than all other sampling periods. There was vertical and horizontal loading of P which lead to higher available P at the surface in soil depths of 0-15 and 15-30cm than 30-40cm and 40-50cm. Levels of Ca increased slightly with sampling interval but decreased down the profile. The soils were also characterized as follows: strongly acid (pH 5.1 -5. ) The application of 90 kg/ha -1 NPK fertilizer during the 9 months interval gave highest values of N.P, Ca and Mg under the condition of the experiment, indicating that these elements will not be deficient in these soils. Equally, the CEC, organic matter and base saturation had their advantage in the 9 months interval where 90 kg'' was applied. This is cost effective and could be used to improve crop production in Akpabuyo, Nigeria.

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