What Can We Learn From the Water Retention Characteristic of a Soil Regarding Its Hydrological and Agricultural Functions? Review and Analysis of Actual Knowledge

Abstract

The soil properties of the upper soil layer determine the partitioning between infiltration, runoff, and evaporation, key processes related to soil agricultural and hydrological functioning. It is therefore important to have some information on these soil functions based on available and easy‐to‐measure properties. This study presents what we can learn a‐priori from the soil water retention characteristic (WRC) on some important hydrological and agricultural functions. Based on a mathematical expression of the soil WRC, it is possible to estimate: the characteristic length, LC, related to the disruption of hydraulic continuity of the water liquid phase in the soil; the saturated hydraulic conductivity Ks; the unsaturated hydraulic conductivity function of water and air, K(θw) and K(θa); the saturation degree SeFC at field capacity and how long it will take to reach that state; the available water content in the soil, AWC; the capillary head at the wetting front, ψf; the infiltration capacity curve based on the Green and Ampt model, qcap(t); the time to ponding, tp, for any prescribed wetting rate; the cumulative water loss during stage‐1 evaporation; the duration of stage‐1 evaporation. All these a‐priori estimates are valuable and sometimes necessary for efficient design and planning in agricultural and hydrological applications. The values of these estimates depend upon the specific mathematical expression chosen to represent the WRC.

Assessment of trunk microtensiometer as a novel biosensor to continuously monitor plant water status in nectarine trees

“…The hysteresis phenomenon found in the relationships between the two plant water potentials: Ψ trunk vs. Ψ stem ( Figure 8A ), which was more noticeable for Ψ trunk vs. Ψ leaf ( Figure 8B ), was higher for the highest imposed soil water deficit (α=100%). This hysteretic behaviour revealed that the water status of the trunk assumes a dominant role in controlling canopy water status as water stress accumulates, which is related to plant hydraulic conductivity during the daily course ( Assouline, 2021 ). In addition, stomata reopened in the afternoon, as indicated by the recovery values of the diurnal pattern of leaf gas exchange ( Figures 9G–I ).…”

Automated hanging water column for characterizing water retention and hysteresis of coarse‐textured porous media

“…The measurement time is highly variable in each method, and a longer equilibration time is required as h becomes smaller (i.e., more negative). However, there is no single method to characterize a continuous water retention process across the full range of h (Assouline, 2021).…”

Factors governing soil hydrological function under long‐term tillage practices: Insight into soil water repellency

“…Soil water storage (SWS) and availability are two common indicators of soil hydrological function (Assouline, 2021), reflecting the ease of absorbing soil water for crops (Filho et al., 2013; Li et al., 2020). Plant available water (PAW) and least limiting water range (LLWR) are commonly applied to measure the soil water availability for plants from different angles (Asgarzadeh et al., 2014).…”

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