Root System Response to Drought and Salinity: Root Distribution and Water Transport

2014 ◽  
pp. 325-352 ◽  
Author(s):  
M. Jesús Sánchez-Blanco ◽  
Sara Álvarez ◽  
M. Fernanda Ortuño ◽  
M. Carmen Ruiz-Sánchez
Keyword(s):  
Root System ◽  
Water Transport ◽  
Root Distribution ◽  
System Response

Towards the consideration of soil-root resistances in root water uptake models with macroscopic representations of hydraulic root architecture

2021 ◽  
Author(s):  
Jan Vanderborght ◽  
Valentin Couvreur ◽  
Felicien Meunier ◽  
Andrea Schnepf ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Water Uptake ◽  
Root Distribution ◽  
Root Architecture ◽  
Soil Layer ◽  
Root Water Uptake ◽  
Hydraulic Architecture ◽  
Root Segments ◽  
Soil Volume

<p>Plant water uptake from soil is an important component of terrestrial water cycle with strong links to the carbon cycle and the land surface energy budget. To simulate the relation between soil water content, root distribution, and root water uptake, models should represent the hydraulics of the soil-root system and describe the flow from the soil towards root segments and within the 3D root system architecture according to hydraulic principles. We have recently demonstrated how macroscopic relations that describe the lumped water uptake by all root segments in a certain soil volume, e.g. in a thin horizontal soil layer in which soil water potentials are uniform, can be derived from the hydraulic properties of the 3D root architecture. The flow equations within the root system can be scaled up exactly and the total root water uptake from a soil volume depends on only two macroscopic characteristics of the root system: the root system conductance, K<sub>rs</sub>, and the uptake distribution from the soil when soil water potentials in the soil are uniform, <strong>SUF</strong>. When a simple root hydraulic architecture was assumed, these two characteristics were sufficient to describe root water uptake from profiles with a non-uniform water distribution. This simplification gave accurate results when root characteristics were calculated directly from the root hydraulic architecture. In a next step, we investigate how the resistance to flow in the soil surrounding the root can be considered in a macroscopic root water uptake model. We specifically investigate whether the macroscopic representation of the flow in the root architecture, which predicts an effective xylem water potential at a certain soil depth, can be coupled with a model that describes the transfer from the soil to the root using a simplified representation of the root distribution in a certain soil layer, i.e. assuming a uniform root distribution.</p>

scholarly journals Evaluation of Water Uptake and Root Distribution of Cherry Trees Under Different Irrigation Methods

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 495 ◽  
Author(s):  
Pingfeng Li ◽  
Huang Tan ◽  
Jiahang Wang ◽  
Xiaoqing Cao ◽  
Peiling Yang
Keyword(s):  
Water Use Efficiency ◽  
Water Absorption ◽  
Root System ◽  
Water Use ◽  
Irrigation Water ◽  
Drip Irrigation ◽  
Root Distribution ◽  
Surface Irrigation ◽  
Irrigation Methods ◽  
Use Efficiency

Although water-saving measures are increasingly being adopted in orchards, little is known about how different irrigation methods enhance water use efficiency at the root system level. To study the allocation of water sources of water absorption by cherry roots under two irrigation methods, surface irrigation and drip irrigation, oxygen isotope tracing and root excavation were used in this study. We found that different irrigation methods have different effects on the average δ18O content of soil water in the soil profile. The IsoSource model was applied to calculate the contribution rate of water absorption by cherry roots under these irrigation methods. During the drought period in spring (also a key period of water consumption for cherry trees), irrigation water was the main source of water absorbed by cherry roots. In summer, cherry roots exhibited a wide range of water absorption sources. In this case, relative to the surface irrigation mode, the drip irrigation mode demonstrated higher irrigation water use efficiency. After two years of the above experiment, root excavation was used to analyze the effects of these irrigation methods on the distribution pattern of roots. We found that root distribution is mainly affected by soil depth. The root system indexes in 10–30 cm soil layer differ significantly from those in other soil layers. Drip irrigation increased the root length density (RLD) and root surface area (RSA) in the shallow soil. There was no significant difference in root biomass density (RBD) and root volume ratio (RVR) between the two irrigation treatments. The effects of these irrigation methods on the 2D distribution of cherry RBD, RLD, RSA and RVR, which indicated that the cherry roots were mainly concentrated in the horizontal depths of 20 to 100 cm, which was related to the irrigation wet zone. In the current experiment, more than 85% of cherry roots were distributed in the space with horizontal radius of 0 to 100 cm and vertical depth of 0 to 80 cm; above 95% of cherry roots were distributed in the space with the horizontal radius of 0 to 150 cm and the vertical depth of 0 to 80 cm. Compared with surface irrigation, drip irrigation makes RLD and RSA more concentrated in the horizontal range of 30–100 cm and vertical range of 0–70 cm.

Modeling soil-root water transport with non-uniform water supply and heterogeneous root distribution

2004 ◽  
Vol 260 (1/2) ◽  
pp. 205-224 ◽  
Author(s):  
Laurent Bruckler ◽  
François Lafolie ◽  
Claude Doussan ◽  
François Bussières
Keyword(s):  
Water Supply ◽  
Water Transport ◽  
Root Distribution

Combined effects of contrast between poor and rich patches and overall nitrate concentration on Arabidopsis thaliana root system structure

2011 ◽  
Vol 38 (5) ◽  
pp. 364 ◽  
Author(s):  
Manuel Blouin ◽  
Ruben Puga-Freitas
Keyword(s):  
Root System ◽  
Nutrient Status ◽  
System Structure ◽  
System Response ◽  
Correlative Inhibition ◽  
The Rich ◽  
The Difference ◽  
Set Up ◽  
The Cost

The law of correlative inhibition states that roots in a richer environment develop more intensively if other roots of the same plant are in a poorer environment. This probably occurs only when the cost of emitting these roots in the rich patch is compensated by the advantage of having more roots, i.e. in situations where the difference in concentration between rich and poor patches is strong or the overall nutrient amount in the environment is low. For the first time, we tested root system response to combined gradients of contrast between poor and rich patches and of overall NO3– concentration in agar gels. We set up a factorial in vitro experiment crossing contrast (null, weak, strong heterogeneity) with overall NO3– concentration (deficient, optimal, excessive). We observed an increase in ramification density with increasing heterogeneity in deficient situations; but a decrease with increasing heterogeneity in excessive situations. The interaction between overall NO3– concentration and heterogeneity had a significant effect on root ramification density and the distribution of root length in diameter classes. The overall nutrient status of the soil has to be considered to understand the effect of heterogeneity on plant development at the morphological as well as at the molecular level.

scholarly journals Root System Distribution Influences Substrate Moisture Measurements in Containerized Ornamental Tree Species

2013 ◽  
Vol 23 (6) ◽  
pp. 754-759 ◽  
Author(s):  
Taryn L. Bauerle ◽  
William L. Bauerle ◽  
Marc Goebel ◽  
David M. Barnard
Keyword(s):  
Root System ◽  
Tree Species ◽  
Root Distribution ◽  
Fine Root ◽  
Soil Layer ◽  
Specific Root Length ◽  
Root Systems ◽  
Moisture Sensor ◽  
Substrate Moisture ◽  
Moisture Variability

Substrate moisture sensors offer an affordable monitoring system for containerized tree production. However, root system distribution can vary greatly among species within ornamental container production systems, resulting in variation within substrate readings among sensors within a container. The aim of this study was to examine the relationship of substrate moisture sensor readings in six ornamental trees to their root distribution patterns within a container. Following root anatomical analysis, tree root systems were dissected by root order as a means to separate fine (uptake) roots and coarse (transport) roots. Substrate moisture variability was measured through the deployment of 12 substrate moisture sensors per container. Of the tree species studied, we found the following two patterns of root distribution: a shallow, “conical-shaped,” root system, with the broadest portion of the root system in the shallow soil layer, and a more evenly distributed “cylindrical-shaped” root system. Root system distribution type influenced substrate moisture reading variability. Conical root systems had lower substrate moisture variability and high fine root variability, whereas the opposite was true for cylindrical root systems—most likely due to the larger, coarse woody mass of roots. We were unable to find any correlations between fine root morphological features including root diameter, length, or surface area and substrate moisture variability. However, higher specific root length was associated with higher substrate moisture variability. Classifying a tree’s root system by its growth and distribution within a container can account for variation in substrate moisture readings and help inform future decisions on sensor placement within containerized systems.

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