ABSTRACT:

The study was carried out to determine the distribution of different forms of K, its availability and K-fixationin the soils of Abuja. To achieve these objectives, seven areas within the six area councils of the FCT wereselected and in each area two locations were selected giving a total of fourteen (14) locations sampled. Thesoil samples were collected at two predetermined depths of 0 – 30 and 30 – 60 cm,s giving a total of twentyeight(28) samples. The collected soil samples were prepared and analysed in the laboratory followingstandard laboratory procedures. The result showed that the exchangeable K in the soils ranged from 0.17 –0.30 cmol/kg. The highest mean content of exchangeable K was observed in the soils of Airport road (0.30cmol/kg) while the least was observed in the soils of Bwari (0.17 cmol/kg). The range of values for theexchangeable K was interpreted as low to moderate. The distribution in the mean of the exchangeable K inthe soils is in the order Airport Road > Abaji area > Kwali area > Karshi area > Gwagwalada area > Kuje >Bwari area. while the mean distribution of H2O extractable K ranged from 0.18 – 1.86 cmol/kg. The trend inthe distribution of the hot water extractable K in the soils across the seven locations is as follows: Kwali area> Gwagwalada Area > Abaji area > Bwari area > Karshi area > AirportRroad > Kuje area. The mean valuefor the soils of Kwali was relatively higher followed by the soils of Gwagwalada while the soils of AirportRoad and Kuje area were the least. The status of NH OAc extractable K ranged 0.010 – 0.032 cmol/kg. The 4mean distribution of ammonium extractable K in the soils was in the order: Bwari area > Karshi area >Kwali area > Airport Road > Gwagwalada = Kuje > Abaji. The mean for Gwagwalada area and Kuje soilswas the same. The potassium fixation in the soil ranged from 0.010 – 0.24 cmol/kg and was interpreted as lowto moderately high. It was concluded that further recommendation for K fertilizer in the soils should take intoaccount the amount of K that is already fixed as a means of curtailing under supply of K Fertilizers to crops inthe field.