Yield determinants, root distribution and soil water uptake in maize (Zea mays) hybrids differing in canopy senescence under post-silking drought

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

10.5194/egusphere-egu21-8151 ◽

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

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, Krs, and the uptake distribution from the soil when soil water potentials in the soil are uniform, SUF. 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.

How to put plant root uptake into a soil water flow model

F1000Research ◽

10.12688/f1000research.7686.1 ◽

2016 ◽

Vol 5 ◽

pp. 43

Author(s):

Xuejun Dong

Keyword(s):

Water Stress ◽

Soil Water ◽

Water Uptake ◽

Root Distribution ◽

Plant Root ◽

Root Water Uptake ◽

Root Uptake ◽

Water Dynamics ◽

Rooting Depth ◽

Plant Root Uptake

The need for improved crop water use efficiency calls for flexible modeling platforms to implement new ideas in plant root uptake and its regulation mechanisms. This paper documents the details of modifying a soil infiltration and redistribution model to include (a) dynamic root growth, (b) non-uniform root distribution and water uptake, (c) the effect of water stress on plant water uptake, and (d) soil evaporation. The paper also demonstrates strategies of using the modified model to simulate soil water dynamics and plant transpiration considering different sensitivity of plants to soil dryness and different mechanisms of root water uptake. In particular, the flexibility of simulating various degrees of compensated uptake (whereby plants tend to maintain potential transpiration under mild water stress) is emphasized. The paper also describes how to estimate unknown root distribution and rooting depth parameters by the use of a simulation-based searching method. The full documentation of the computer code will allow further applications and new development.

Root water uptake and profile soil water as affected by vertical root distribution

Plant Ecology ◽

10.1007/s11258-006-9163-y ◽

2006 ◽

Vol 189 (1) ◽

pp. 15-30 ◽

Cited By ~ 54

Author(s):

Gui-Rui Yu ◽

Jie Zhuang ◽

Keiichi Nakayama ◽

Yan Jin

Keyword(s):

Soil Water ◽

Water Uptake ◽

Root Distribution ◽

Root Water Uptake ◽

Vertical Root Distribution

Comparison of the Roles of Optimizing Root Distribution and the Water Uptake Function in Simulating Water and Heat Fluxes within a Maize Agroecosystem

Water ◽

10.3390/w10081090 ◽

2018 ◽

Vol 10 (8) ◽

pp. 1090 ◽

Cited By ~ 2

Author(s):

Fu Cai ◽

Yushu Zhang ◽

Huiqing Ming ◽

Na Mi ◽

Shujie Zhang ◽

...

Keyword(s):

Soil Water ◽

Water Uptake ◽

Land Surface ◽

Root Distribution ◽

Model Performance ◽

Heat Fluxes ◽

Land Surface Models ◽

Field Station ◽

Common Land Model ◽

Surface Models

Roots are an important water transport pathway between soil and plant. Root water uptake (RWU) plays a key role in water and heat exchange between plants and the atmosphere. Inaccurate RWU schemes in land surface models are one crucial reason for decreased model performance. Despite some types of RWU functions being adopted in land surface models, none have been certified as suitable for maize farmland ecosystems. Based on 2007–2009 data observed at the maize agroecosystem field station in Jinzhou, China, the RWU function and root distribution (RD) in the Common Land Model (CoLM) were optimized and the effects of the optimizations on model performance were compared. Results showed that RD parameters calculated with root length density were more practical relative to root biomass in reflecting soil water availability, and they improved the simulation accuracy for water and heat fluxes. The modified RWU function also played a significant role in optimizing the simulation of water and heat fluxes. Similarly, the respective and integrated roles of two optimization schemes in improving CoLM performance were significant during continuous non-precipitation days, especially during the key water requirement period of maize. Notably, the improvements were restrained within a threshold of soil water content, and the optimizations were inoperative outside this threshold. Thus, the optimized RWU function and the revised RD introduced into the CoLM model are applicable for simulation of water and heat fluxes for maize farmland ecosystems in arid areas.

An exponential root-water-uptake model

Canadian Journal of Soil Science ◽

10.4141/s98-032 ◽

1999 ◽

Vol 79 (2) ◽

pp. 333-343 ◽

Cited By ~ 44

Author(s):

K. Y. Li ◽

J. B. Boisvert ◽

R. De Jong

Keyword(s):

Soil Water ◽

Water Uptake ◽

Root Distribution ◽

Maximum Error ◽

Root Water Uptake ◽

Exponential Model ◽

Rate Model ◽

Loam Soil ◽

Water Contents ◽

Soil Water Contents

Macroscopic root-water-extraction models often do not adequately account for the non-uniform distribution of roots in the soil profile. We developed an exponential root-water-uptake model, which was derived from a measured root density distribution function. The model, incorporated in the Soil-Water-Atmosphere-Plant (SWAP) simulation model, was tested on a clay loam soil cropped to soybeans and on a sandy loam soil cropped to corn, near Ottawa. Comparisons of measured and simulated soil water contents with the exponential model, a linear depth-dependent model and a constant-extraction-rate model were also made. The exponential model performed satisfactorily (average relative errors <20%) when used to simulate measured field soil water contents at various depths. The constant-extraction-rate model overestimated the soil water contents in the upper part of the soil profile (maximum error 0.24 cm3 cm−3) and underestimated them (maximum error −0.09 cm3 cm−3) in the lower part. The exponential model and the linear model performed fairly similarly at the lower depths, but the exponential model gave better results in the near-surface horizons. The exponential model was sensitive to the root distribution coefficient and to the rooting depth, when the latter was approximately less than 40 cm. The results of this study suggest that the exponential root-water-uptake model as incorporated in SWAP is an improvement over those models, which do not account for the root distribution in the soil. Key words: SWAP, soil water simulation, root distribution, corn, soybeans, sensitivity analysis

Soil water uptake and root distribution of different perennial and annual bioenergy crops

Plant and Soil ◽

10.1007/s11104-014-2335-y ◽

2014 ◽

Vol 388 (1-2) ◽

pp. 307-322 ◽

Cited By ~ 37

Author(s):

Fabien Ferchaud ◽

Guillaume Vitte ◽

Frédéric Bornet ◽

Loïc Strullu ◽

Bruno Mary

Keyword(s):

Soil Water ◽

Water Uptake ◽

Root Distribution ◽

Bioenergy Crops

Genotypic variation in soil water use and root distribution and their implications for drought tolerance in chickpea

Functional Plant Biology ◽

10.1071/fp16154 ◽

2017 ◽

Vol 44 (2) ◽

pp. 235 ◽

Cited By ~ 11

Author(s):

Ramamoorthy Purushothaman ◽

Lakshmanan Krishnamurthy ◽

Hari D. Upadhyaya ◽

Vincent Vadez ◽

Rajeev K. Varshney

Keyword(s):

Soil Water ◽

Water Use ◽

Water Uptake ◽

Root Distribution ◽

Root Length Density ◽

Soil Depth ◽

Genotypic Variation ◽

Yield Losses ◽

Total Water ◽

Deep Soil

Chickpeas are often grown under receding soil moisture and suffer ~50% yield losses due to drought stress. The timing of soil water use is considered critical for the efficient use of water under drought and to reduce yield losses. Therefore the root growth and the soil water uptake of 12 chickpea genotypes known for contrasts in drought and rooting response were monitored throughout the growth period both under drought and optimal irrigation. Root distribution reduced in the surface and increased in the deep soil layers below 30 cm in response to drought. Soil water uptake was the maximum at 45–60 cm soil depth under drought whereas it was the maximum at shallower (15–30 and 30–45 cm) soil depths when irrigated. The total water uptake under drought was 1-fold less than optimal irrigation. The amount of water left unused remained the same across watering regimes. All the drought sensitive chickpea genotypes were inferior in root distribution and soil water uptake but the timing of water uptake varied among drought tolerant genotypes. Superiority in water uptake in most stages and the total water use determined the best adaptation. The water use at 15–30 cm soil depth ensured greater uptake from lower depths and the soil water use from 90–120 cm soil was critical for best drought adaptation. Root length density and the soil water uptake across soil depths were closely associated except at the surface or the ultimate soil depths of root presence.

The Root-Soil Water Relationship Is Spatially Anisotropic in Shrub-Encroached Grassland in North China: Evidence from GPR Investigation

Remote Sensing ◽

10.3390/rs13061137 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1137

Author(s):

Xihong Cui ◽

Zheng Zhang ◽

Li Guo ◽

Xinbo Liu ◽

Zhenxian Quan ◽

...

Keyword(s):

Soil Water ◽

Root Distribution ◽

Preferential Flow ◽

Distribution Density ◽

Vertical Direction ◽

Additive Models ◽

Depth Interval ◽

Soil Core ◽

Semi Arid ◽

Free Area

To analyze the root-soil water relationship at the stand level, we integrated ground-penetrating radar (GPR), which characterized the distribution of lateral coarse roots (>2 mm in diameter) of shrubs (Caragana microphylla Lam.), with soil core sampling, which mapped soil water content (SWC) distribution. GPR surveys and soil sampling were carried out in two plots (Plot 1 in 2017 and Plot 2 in 2018) with the same size (30 × 30 m2) in the sandy soil of the semi-arid shrubland in northern China. First, the survey area was divided into five depth intervals, i.e., 0–20, 20–40, 40–60, 60–80, and 80–100 cm. Each depth interval was then divided into three zones in the horizontal direction, including root-rich canopy-covered area, root-rich canopy-free area, and root-poor area, to indicate different surface distances to the canopy. The generalized additive models (GAMs) were used to analyze the correlation between root distribution density and SWC after the spatial autocorrelation of each variable was eliminated. Results showed that the root-soil water relationship varies between the vertical and horizontal directions. Vertically, more roots are distributed in soil with high SWC and fewer roots in soil with low SWC. Namely, root distribution density is positively correlated with SWC in the vertical direction. Horizontally, the root-soil water relationship is, however, more complex. In the canopy-free area of Plot 1, the root-soil water relationship was significant (p < 0.05) and negatively correlated in the middle two depth intervals (20–40 cm and 40–60 cm). In the same two depth intervals in the canopy-free area of Plot 2, the root-soil water relationship was also significant (p < 0.01) but non-monotonic correlated, that is, with the root distribution density increasing, the mean SWC decreased first and then increased. Moreover, we discussed possible mechanisms, e.g., root water uptake, 3D root distribution, preferential flow along roots, and different growing stages, which might lead to the spatially anisotropic relationship between root distribution and SWC at the stand level. This study demonstrates the advantages of GPR in ecohydrology studies at the field scale that is challenging for traditional methods. Results reported here complement existing knowledge about the root-soil water relationship in semi-arid environments and shed new insights on modeling the complex ecohydrological processes in the root zone.

Root Response to Soil Water Status via Interaction of Crop Genotype and Environment

Agronomy ◽

10.3390/agronomy11040708 ◽

2021 ◽

Vol 11 (4) ◽

pp. 708

Author(s):

Phanthasin Khanthavong ◽

Shin Yabuta ◽

Hidetoshi Asai ◽

Md. Amzad Hossain ◽

Isao Akagi ◽

...

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Root Distribution ◽

Water Status ◽

Soil Layer ◽

Shoot Biomass ◽

Soil Conditions ◽

Crop Adaptation ◽

Soil Moisture Status ◽

Root Distributions

Flooding and drought are major causes of reductions in crop productivity. Root distribution indicates crop adaptation to water stress. Therefore, we aimed to identify crop roots response based on root distribution under various soil conditions. The root distribution of four crops—maize, millet, sorghum, and rice—was evaluated under continuous soil waterlogging (CSW), moderate soil moisture (MSM), and gradual soil drying (GSD) conditions. Roots extended largely to the shallow soil layer in CSW and grew longer to the deeper soil layer in GSD in maize and sorghum. GSD tended to promote the root and shoot biomass across soil moisture status regardless of the crop species. The change of specific root density in rice and millet was small compared with maize and sorghum between different soil moisture statuses. Crop response in shoot and root biomass to various soil moisture status was highest in maize and lowest in rice among the tested crops as per the regression coefficient. Thus, we describe different root distributions associated with crop plasticity, which signify root spread changes, depending on soil water conditions in different crop genotypes as well as root distributions that vary depending on crop adaptation from anaerobic to aerobic conditions.

Analysis of Soil Water Response to Grass Transpiration

Soil and Water Research ◽

10.17221/6510-swr ◽

2013 ◽

Vol 1 (No. 3) ◽

pp. 85-98

Author(s):

Dohnal Michal ◽

Dušek Jaromír ◽

Vogel Tomáš ◽

Herza Jiří

Keyword(s):

Soil Water ◽

Water Uptake ◽

Preferential Flow ◽

Water Movement ◽

Control Volume ◽

Water Pressure ◽

Lower Boundary ◽

Root Water Uptake ◽

Water Dynamics ◽

Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards’ equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.