Pedological Properties and Classification of Soils Underlain by Asu River Group Parent Materials in Ohaozara, Southeastern Nigeria

The study was carried out in Ohaozara Southern Ebonyi State in Southeastern Nigeria and aimed at studying the pedological properties as well as classifying the soils underlain by Asu River group parent material. Study area was identified in a rice soil of about 120 hectares used by FGN/IFAD Value Chain Development program (VCDP). Three profile pits were dug on a transect line of about 100 – 200m apart. Samples were collected and analyzed using standard procedures. Soil colours ranged from yellow (5YR7/3) at the A horizon to reddish yellow (5YR7/8) at the Bt2 horizon of pedon in location 1 when measured under dry condition. Also at the location 1 when soils were measured under moist condition, the colours ranged from very pale brown (10YR7/3) at the topmost horizon to reddish yellow (7.5YR7/8) at the Bt2 horizon. At location 2, soil colour ranged from white (5YR8/1) at the topmost horizon to reddish yellow (10YR7/6) at the Bt2 horizon when dry. However, when moist it ranged from light grey (7.5YR7/1) to strong brown (7.5YR5/6) from top to bottom of the profile. Location 3 had colours ranging from light grey (5YR7/1) at the top to yellow (10YR8/4) at the bottom when dry and from very pale brown (10YR7/3) to yellow (5YR7/6) from horizon A to horizon Bt2 when moist. Silt-clay ratios decreased down the profile in all investigated locations and scored means of 0.95, 1.02 and 1.10 in locations 1, 2 and 3 respectively. Bulk density and porosity had an opposite trend as bulk density increased down the profile, porosity decreased down the profile. The means of bulk density were 1.34, 1.44 and 1.32 g/cm3 while the means of the porosity were 49.34, 45.66 and 50.17 % in locations 1, 2 and 3 respectively. Therefore, pedon 1 is classified as Typic Eutrudept (USDA) and Eutric Cambisols (WRB) while pedons 2 and 3 were classified as Aquic Eutrudepts (USDA) and Gleyic Leptosols (WRB).