Plant Morphological Structures as Influenced by Soil Hydraulic Properties: A Review

ABSTRACT A review of published literatures was conducted with an attempt to draw together existing knowledge of plant–Soil Hydraulic Properties (SHP) relationships to benefit hydrology practitioners, particularly modelers. This study aims to integrate and build on a significant body of previous research to identify the state of current knowledge and available guidance on SHP. Different authors used different methodologies and models to achieve their specific objectives. The methods used by most researchers to determine saturated hydraulic conductivity (K sat) and other SHP include constant head and falling head permeameter method, pycnometer method, infiltrometer, soil moisture probe and tensiometer. The van Genuchten (VG) model, soil–water–air–plant (SWAP) model were also used by many researchers. This paper reviews these approaches and methods with a view to help improve SHP under different cropping system. Some studies demonstrated that cover crops slightly improve some SHP in claypan soils, but the changes may take several years, while others show the importance of SHP for crop development in highly degraded soils. Furthermore, various researches have shown that simultaneous estimation of water stress and SHP cannot be robustly performed using measurements of transpiration or dry matter yield alone. In the same vein, some studies have shown that some hydraulic properties were improved with a combination of both tillage and cover crop management practices. This review revealed that the relationship between plant (crop) morphology and soil hydraulic interactions was evident and certain crops (cover crops) and roots of some tree plants tend to slightly improve SHP and other soil qualities.