Determining the Field Capacity, Wilting point and Available Water Capacity of some Southeast Nigerian Soils using Soil Saturation from Capillary Rise

Abstract

Water is a unique material resource which plays a vital role in nature and in agriculture. The objective of this study was to find out the applicability of saturation percentage (SP) to estimate field capacity (FC) and permanent wilting point (PWP) of soils across different texture in southeast Nigeria. Top 0-20 cm soil sample were randomly collected from 28 points in different parts of southeast Nigeria and analyzed for particle size distribution, organic carbon (OC %) and moisture constants. Simple correlations and regression models were used to relate the moisture constants at various suctions to saturation percentage (SP).Results of the study showed that sand, silt and clay contents of the soils ranged between 2-73%, 2-48% and 8-76%, respectively. Similarly, OC % ranged between 0.08- 3.03 % while the ranges of 24.3-75.7, 8.3-50.5% and 2.3-32.6% were observed for SP, FC and PWP, respectively. Results showed strong linear relationship between SP and the moisture constants (FC, PWP) and that the readily available water capacity (RAWC) and total available water capacity (TAWC) cannot be estimated from SP across the texture of the studied soils.

Keywords: Moisture constants, Agriculture, Saturation percentage, texture, Water

Nig J. Biotech. Vol. 24 (2012) 41-47