The soil’s hydraulic properties, particularly its water retention and movement characteristics, are vital for managing soil water availability. Accurate understanding of these properties is essential for sustainable soil water conservation. Parameters such as field capacity (FC), permanent wilting point (PWP), and hydraulic conductivity (Ks) significantly influence soil moisture retention, but their direct measurement is intricate and costly. To address this challenge, the Saxton and Rawl Soil Water Characteristics-Hydraulic Properties Calculator (SWC-HPC) model offers an alternative by estimating these parameters using readily available soil data.
In this research, we collected 180 soil samples from three diverse sites in Niger State: Minna (Ferruginous tropical soil), Badeggi (Hydromorphic soil), and Mokwa (Ferrosol), representing major soil types. Soil water characteristic values were obtained from laboratory analysis of soil samples taken from nine profile pits measuring 2m x 1m x 1.5m. Soil bulk samples and undisturbed core samples were collected progressively from a depth of 20cm to 100cm. The independent variables in the study included percentage composition of sand, clay, and silt, as well as organic matter content, salinity, and compaction. The dependent variables encompassed wilting point, field capacity, saturation point, hydraulic conductivity, bulk density, and plant available moisture content.
To evaluate the SWC-HPC model, we employed statistical measures such as root mean square error (RMSE), coefficient of variation (CV), modelling efficiency (EF), coefficient of residual mass (CRM), and chi-square, comparing model outputs to observed laboratory parameters. The model exhibited accurate predictions of soil bulk densities, satisfactory simulation of soil moisture content at permanent wilting point, and moderate simulation of plant available water. However, the model’s predictions for saturated hydraulic conductivity and soil moisture content at field capacity were less accurate. Consequently, the SWC-HPC model is suitable primarily for simulating soil bulk densities, moisture conditions at permanent wilting point, and plant available water values across the three study locations in Niger State.
EFFICIENCY EVALUATION OF SOIL-WATER MODEL FOR DOMINANT SOILS IN NIGER STATE, NIGERIA, GET MORE, ACTUARIAL SCIENCE PROJECT TOPICS AND MATERIALS
