Authors : V.E. Osodeke and V.E. Osodeke
Abstract: The distribution of various forms of phosphorus was evaluated along a topsequence located on a coastal plain sand parent material in Amaoba Ime, Ikwuano Local Government area of Abia State. The toposequence was delineated into different topographic units (Crest, Upper slope, Middle slope, Lower slope and Valley bottom). Soil samples were collected from identified horizons in profile pits in each topographic unit. The soil samples were analyzed for total, organic and available P forms. The active forms of P were also determined. The results obtained showed that total P ranged from 150 � 787.5 µgg-1 with a mean of 439 µgg-1. Total P was highest at the upper slope and lowest at the middle slope. Organic P ranged from 33 to 186µgg-1 with a mean of 91µgg-1. Organic P was highest at the valley bottom and lowest at the middle slope. The active P forms was in the order of Fe � P > Al- P > Ca �P, with Fe-P varying from 21 � 196 µgg-1 while Al-P ranged from 1.75 �63.63µgg-1. There was no regular pattern of distribution of active P forms along the toposequence. Available P ranged from 0.69 to 11.79µgg-1 with a mean of 3.63. The total P correlated positively with inactive P (r = 0.93**), organic P correlated positively with clay and negatively with sand (r = 0.43*, r = -0.53**). Fe-P and Al-P correlated with magnesium and sand respectively. Phosphorus distribution vary widely with each topographic unit.
Osodeke, V.E. and Osodeke, V.E. , 2006. Phosphorus Distribution along a Toposequence of Coastal Plain Sand Parent Material in Southeastern Nigeria. Agricultural Journal, 1: 167-171.