Root System Response of a Perennial Bunchgrass to Neighbourhood-Scale Soil Water Heterogeneity

1994 ◽  
Vol 8 (6) ◽  
pp. 738 ◽  
Author(s):  
P. B. Hook ◽  
W. K. Lauenroth
Keyword(s):  
Root System ◽  
Soil Water ◽  
System Response ◽  
Water Heterogeneity ◽  
Neighbourhood Scale

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 Soil water extraction by roots and Kc for the coffee crop

2009 ◽  
Vol 13 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Adriana L. da Silva ◽  
Isabeli P. Bruno ◽  
Klaus Reichardt ◽  
Osny O. S. Bacchi ◽  
Durval Dourado-Neto ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Dry Matter ◽  
Soil Layer ◽  
Water Extraction ◽  
Area Index ◽  
Direct Measurements ◽  
Top Soil ◽  
Soil Water Extraction ◽  
Crop Coefficients

Basic information for a rational soil-water management of the coffee crop is still insufficient, particularly under irrigated conditions. Of great importance for the estimation of water requirements of coffee crops are their root distribuition and evapotranspiration crop coefficients. This study compares soil water extraction by roots of coffee plants of the variety "Catuaí Vermelho" (IAC-44), grown in Piracicaba, SP, Brazil, 3 to 5 years old, with direct measurements of root dry matter, showing a good agreement between both approaches, and confirming that most of the root system is distributed in the top soil layer (0-0.3 m) and that less than 10% of the root system reaches depths greater than 1.0 m. Calculated evapotranspiration crop coefficients are in agreement with those found in the literature, with an average of 1.1, independent of shoot dry matter, plant height and leaf area index.

Water relations of winter wheat. 5. The root system and osmotic adjustment in relation to crop evaporation

1984 ◽  
Vol 102 (2) ◽  
pp. 415-425 ◽  
Author(s):  
M. McGowan ◽  
P. Blanch ◽  
P. J. Gregory ◽  
D. Haycock
Keyword(s):  
Winter Wheat ◽  
Water Potential ◽  
Root System ◽  
Soil Water ◽  
Osmotic Adjustment ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Plant Water ◽  
Potential Evaporation ◽  
Plant Water Potential

SummaryShoot and root growth and associated leaf and soil water potential relations were compared in three consecutive crops of winter wheat grown in the same field. Despite a profuse root system the crop grown in the second drought year (1976) failed to dry the soil as throughly as the crops in 1975 and 1977. Measurements of plant water potential showed that the restricted utilization of soil water reserves by this crop was associated with failure to make any significant osmotic adjustment, leading to premature loss of leaf turgor and stomatal closure. The implications of these results for models to estimate actual crop evaporation from values of potential evaporation are discussed.

scholarly journals Relationship between Very Fine Root Distribution and Soil Water Content in Pre- and Post-Harvest Areas of Two Coniferous Tree Species

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1227
Author(s):  
Moein Farahnak ◽  
Keiji Mitsuyasu ◽  
Takuo Hishi ◽  
Ayumi Katayama ◽  
Masaaki Chiwa ◽  
...  
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Tree Species ◽  
Fine Roots ◽  
Fine Root ◽  
Soil Depth ◽  
Tree Cutting ◽  
Coniferous Tree Species

Tree root system development alters forest soil properties, and differences in root diameter frequency and root length per soil volume reflect differences in root system function. In this study, the relationship between vertical distribution of very fine root and soil water content was investigated in intact tree and cut tree areas. The vertical distribution of root density with different diameter classes (very fine <0.5 mm and fine 0.5–2.0 mm) and soil water content were examined along a slope with two coniferous tree species, Cryptomeria japonica (L.f.) D. Don and Chamaecyparis obtusa (Siebold et Zucc.) Endl. The root biomass and length density of very fine roots at soil depth of 0–5 cm were higher in the Ch. obtusa intact tree plot than in the Cr. japonica intact plot. Tree cutting caused a reduction in the biomass and length of very fine roots at 0–5 cm soil depth, and an increment in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot one year after cutting. However, very fine root density of the Cr. japonica intact tree plot was quite low and the soil water content in post-harvest areas did not change. The increase in soil water content at 5–30 cm soil depth of the Ch. obtusa cut tree plot could be caused by the decrease in very fine roots at 0–5 cm soil depth. These results suggest that the distribution of soil water content was changed after tree cutting of Ch. obtusa by the channels generated by the decay of very fine roots. It was also shown that differences in root system characteristics among different tree species affect soil water properties after cutting.

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

Resistance to water uptake by irrigated potatoes on a duplex soil

Soil Research ◽  
1990 ◽  
Vol 28 (4) ◽  
pp. 487 ◽  
Author(s):  
MA Rab ◽  
KA Olsson ◽  
ST Willatt
Keyword(s):  
Root System ◽  
Soil Water ◽  
Plant Resistance ◽  
Root Length ◽  
Hydraulic Properties ◽  
Potato Crop ◽  
Soil Resistance ◽  
Soil Hydraulic Properties ◽  
Matric Potential ◽  
Soil Hydraulic

Resistances to water flow were analysed for the soil-root system of a potato crop growing on a duplex soil-where soil hydraulic properties varied with depth-under two irrigation regimes: 'wet' (irrigated weekly) and 'dry' (irrigated twice only during the growing season). The relative magnitudes of the soil and plant resistances controlling root water uptake were evaluated over depth and time using field-measured soil hydraulic properties and root length densities in successive soil layers. Resistance to water flow in the root system is likely to be the dominant resistance in the liquid phase, although soil resistance increased more rapidly than plant resistance with decreasing soil-water matric potential and root length density. Soil resistance reached similar values to plant resistance only when the soil-water matric potential was in the range -900 kPa to -1500 kPa (corresponding soil hydraulic conductivities of 10-7 and 10-8 m day-1 respectively), depending on the root length beneath unit ground area in the soil layer, La. Poor utilization of water from depth of this soil was attributed to resistance in the root system (possibly radial) associated with low La. Practical considerations for improved water management of the potato crop on clay soils are discussed.

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