Influence of soil depth and texture on moisture characteristics and plant available water content of Alfisols in northern Guinea Savannah of Nigeria

This study was designed   to find out the influence of soil texture and depth on soil volumetric moisture retention (𝜃) in percentage at three matric potentials (0, 0.3, and 15 bars suction) and Plant Available Water Content (PAWC) on Nigerian Northern Guinea Savannah (NGS) Alfisols. After laboratory moisture determination using pressure plate apparatus, descriptive statistics was employed to summarize the data of disturbed soils sampled   from four depth  (0-20cm; 20-40cm; 40-60cm; and 60-80cm), and grouped by surface layer textures into Sandy-Loam (SL), Loam (L), Loamy-Sand (LS), Sandy Clay-Loam (SCL), and Clay-Loam (CL). Generally, all the moisture characteristics increased with depth in the overall study area. Sandy Clay-Loam (SCL) however, retained the highest moisture at saturation (76.6±11%) in term of textural groups. For moisture retention at Drained Upper Limit (DUL), Drained Lower Limit (DLL) and Plant Available Water Content PAWC, Clay-Loam texture group retained the highest with 33.3±6, 18.6±4%, and 14.7±1% respectively. It could therefore be concluded that CL texture exhibited the ability to retain the most agriculturally important moisture characteristics, while the moisture availability itself increase down soil depth in NGS irrespective of its texture.