Investigation of Wetland Soil Properties affecting Optimum Soil Cultivation

Abstract

An investigation was carried out on wetland (fadama) soil properties affecting optimum soil cultivation. A cone penetrometerand a shear vane apparatus (19 mm) were used to determine the cone index and the torque that cause the soil to shearat different moisture contents. The study shows that the cone index and shear vane of fadama soils increased with depth anddecreased with increase in moisture content. High moisture content reduced the soil cohesion. The internal frictional angleof the soil was 37.90. The following values were obtained for soil cohesion 112 kN/m2, 62 kN/m2, 38 kN/m2, 30 kN/m2, and12 kN/m2 at moisture contents of 0%, 5%, 10%, 15% and 20% respectively. Moisture content between 10% -15% (dry basis)appeared ideal for cultivation of the soil. For this soil the critical moisture content was found to be 23.72%. Moisture contentbeyond the critical level needs to be drained before cultivation is carried out.

Keywords

• Wetland
• fadama
• moisture content
• cone index
• shear vane
• shear torque
• internal frictional angle
• soil cohesion.