Predicting soil water content at − 33 kPa by pedotransfer functions in stoniness 1 soils in northeast Venezuela

Abstract

Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach's PTF presented the best performance in relation to the others and could be used to estimate WR in soils of Caramacate River basin. The calculated PTFs had a R of 0.65. This was slightly higher than the R of the Urach's PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR.

Particle Size Distribution and Hydraulic Conductivity in Coastal Non-Agricultural Land in Gaza Coastal Plain

“…So far, hydraulic conductivity in soil is directly connected with particles size distribution in soil profile. Several methods have been tested for determination of hydraulic conductivity; this included integrated global soil databases with land use/land cover databases and saturated hydraulic conductivity [13], pedotransfer functions [14], rainfall-induced seals [15] and influence of biochar [16]. These investigations provided valuable information that was applied in agricultural soils around the world.…”

Qualitative Rating System for Drainability of Roadway Base Materials

“…Drainable porosity and minimum saturation can be directly related to field capacity (u f ), which is the volumetric water content retained in the material after excess water has drained by gravity and the rate of flow has decreased. Richards and Weaver (22) noted that field capacity of 71 coarse-and fine-grained soils was most robustly correlated with the moisture retained at a moisture tension of 345 cmH 2 O ( ' 33 kPa), and thus u f is often estimated as the volumetric water content measured from an SWCC along a drainage path at a suction of 33 kPa (e.g., [23][24][25].…”