scholarly journals Modeling the Impact of Biopores on Root Growth and Root Water Uptake

2019 ◽  
Vol 18 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Magdalena Landl ◽  
Andrea Schnepf ◽  
Daniel Uteau ◽  
Stephan Peth ◽  
Miriam Athmann ◽  
...  
Keyword(s):  
Root Growth ◽  
Water Uptake ◽  
Root Water Uptake ◽  
The Impact

scholarly journals Water uptake dynamics under progressive drought stress in diverse accessions of the OryzaSNP panel of rice (Oryza sativa)

2012 ◽  
Vol 39 (5) ◽  
pp. 402 ◽  
Author(s):  
Veeresh R. P. Gowda ◽  
Amelia Henry ◽  
Vincent Vadez ◽  
H. E. Shashidhar ◽  
Rachid Serraj
Keyword(s):  
Oryza Sativa ◽  
Drought Stress ◽  
Root Growth ◽  
Water Uptake ◽  
Root Length Density ◽  
Oryza Sativa L ◽  
Root Water Uptake ◽  
Snp Markers ◽  
Drought Response ◽  
Genotypic Differences

In addition to characterising root architecture, evaluating root water uptake ability is important for understanding drought response. A series of three lysimeter studies were conducted using the OryzaSNP panel, which consists of 20 diverse rice (Oryza sativa L.) genotypes. Large genotypic differences in drought response were observed in this genotype panel in terms of plant growth and water uptake. Total water uptake and daily water uptake rates in the drought-stress treatment were correlated with root length density, especially at depths below 30 cm. Patterns of water uptake among genotypes remained consistent throughout the stress treatments: genotypes that initially extracted more water were the same genotypes that extracted more water at the end of the study. These results suggest that response to drought by deep root growth, rather than a conservative soil water pattern, seems to be important for lowland rice. Genotypes in the O. sativa type aus group showed some of the greatest water uptake and root growth values. Since the OryzaSNP panel has been genotyped in detail with SNP markers, we expect that these results will be useful for understanding the genetics of rice root growth and function for water uptake in response to drought.

scholarly journals A mechanistic model for electrical conduction in soil–root continuum: a virtual rhizotron study

2018 ◽  
Author(s):  
Sathyanarayan Rao ◽  
Félicien Meunier ◽  
Solomon Ehosioke ◽  
Nolwenn Lesparre ◽  
Andreas Kemna ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Root Growth ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Numerical Study ◽  
Root Segments ◽  
Bulk Electrical Conductivity ◽  
The Impact

Abstract. Electrical Resistivity Tomography (ERT) has become an important tool to study soil water fluxes in cropped field. ERT results translates to water content via empirical pedophysical relations that take soil physical properties into account, usually ignoring the impact of roots. Studies shows high root dense soils behaves quite differently than less root dense soils in terms of bulk electrical conductivity. Yet, we do not completely understand the impact of root segments on the ERT measurements. In this numerical study, we coupled an electrical model with a plant-soil water flow model to investigate the impact of plant root growth and water uptake on the ERT virtual experiment. The electrical properties of roots were explicitly accounted in the finite element mesh and we obtained the electrical conductivities of root segments by conducting specific experiments on real maize plants. The contrast between electrical conductivity of roots and soil depends on factors such as root density, irrigation, root age, and root water uptake pattern. Root growth and water uptake processes thus affect this contrast together with the soil electrical properties. Model results indicate a non-negligible anisotropy in bulk electrical conductivity induced by root processes. We see a greater anisotropy in a sandy medium when compared to a loamy medium. We find that the water uptake process dominates the bulk electrical properties. The Gauss-Newton type ERT inversion of virtual rhizotron data demonstrate that, when root-soil electrical conductivity contrasts are high, it can lead to error in water content estimates since the electrical conductivity is partly due to root. Thus, incorporating the impact of root in the pedophysical relations is very important to interpret ERT results directly as water content.

Simulation of soil water dynamics in structured heavy soils with respect to root water uptake

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
David Zumr ◽  
Michal Dohnal ◽  
Miroslav Hrnčíř ◽  
Milena Císlerová ◽  
Tomáš Vogel ◽  
...  
Keyword(s):  
Water Uptake ◽  
Nitrogen Fertilization ◽  
Drip Irrigation ◽  
Soil Profile ◽  
Water Regime ◽  
Root Zone ◽  
Root Water Uptake ◽  
Water Dynamics ◽  
Preferential Pathways ◽  
The Impact

AbstractIn agricultural lands has the soil moisture uptake from the root system a significant effect on the water regime of the soil profile. In texturally heavy soils, where preferential pathways are present, infiltrated precipitation and irrigation water with diluted fertilizers quickly penetrate to a significant depth and often reach an under-root zone or even the ground-water level. Such a scenario is likely to happen during long summer periods without rain followed by heavy precipitation events, when a part of the water may flow through desiccated cracks.Since 2001 the effects of drip irrigation and nitrogen fertilization of potatoes (Solanum tuberosum L., cultivar Agria) have been monitored within the frame of a research project at the experimental site Valecov (Czech Republic). Based upon the measured data an attempt has been made to simulate the water regime of the soil profile at a selected experimental plot, considering the impact of preferential flow and root water uptake. The dual-permeability simulation model S_1D_Dual (VOGEL et al., 2000) was used for the simulation. The soil hydraulic parameters were inversely determined using Levenberg-Marquardt method. Measured and simulated pressure heads were utilized in the optimization criterion. The scaling approach was applied to simplify the description of the spatial variability of the soil profile.The results of simulations demonstrate that during particular rainfall events the water reaches significant depths of the soil profile via preferential pathways. The effect of the root zone is dominant during dry periods, when capillary water uptake from the layers below roots becomes important. This should be taken in account into the optimization of the drip irrigation and nitrogen fertilization schedule.

Variability assessment of Irrigation Requirement for Winter Wheat Cropping Under Changing Climate.

2020 ◽  
Author(s):  
Kaushika Gujjanadu Suryaprakash ◽  
Hari Prasad Kotnur Suryanarayana Rao
Keyword(s):  
Climate Change ◽  
Water Uptake ◽  
Root Water Uptake ◽  
Water Requirement ◽  
Richards Equation ◽  
Emission Scenarios ◽  
Irrigation Requirement ◽  
Moisture Movement ◽  
The Future ◽  
The Impact

<p>India is primarily an agronomic country and most of the cropping in the Rabi season depends on the rainwater availability. With the ill effects of climate change cropping up, the agriculture sector is expected to take a major hit. This study takes a technical approach on the impact of climate change on the irrigation requirement of wheat cropping by studying the future irrigation requirement based on the temperature and rainfall that can be expected to occur in the future timelines. A root water uptake model involving the solution of the non-linear Richards equation to assess the root-zone moisture movement is formulated and validated. The inputs of the model include the crop data, which, in this case is obtained by field experimentation at the irrigation field laboratory at IIT Roorkee and weather data, which is obtained from the CANESM2 General circulation model for the historical and projected timescales. The historical GCM data for thirty years is bias corrected using the observed data from the India Meteorological department (IMD). The validated root water uptake model is applied to the historical and projected data for a 60 year span for two emission scenarios for RCP 4.5 and 8.5. The output was obtained as soil moisture profiles and frequencies of irrigation required. It was seen that for both the mild and high emission scenarios, the number of irrigation events per cropping period increased. This increase is assessed using variability analysis and for its impacts on the water resources management systems. The variability assessment showed the variation of the irrigation water requirement on annual and decadal scales. This is useful in understanding the historical and expected crop water requirement in view of the climate change effects.</p>

scholarly journals The impact of mucilage on root water uptake—A numerical study

2016 ◽  
Vol 52 (1) ◽  
pp. 264-277 ◽  
Author(s):  
N. Schwartz ◽  
A. Carminati ◽  
M. Javaux
Keyword(s):  
Water Uptake ◽  
Numerical Study ◽  
Root Water Uptake ◽  
The Impact

scholarly journals The Impact of Rhizosphere Soil Structure and Mucilage on Root Water Uptake – A Simulation Study

2020 ◽  
Author(s):  
Magdalena Landl ◽  
Maxime Phalempin ◽  
Doris Vetterlein ◽  
Steffen Schlueter ◽  
Mathieu Javaux ◽  
...  
Keyword(s):  
Water Uptake ◽  
Simulation Study ◽  
Soil Structure ◽  
Rhizosphere Soil ◽  
Root Water Uptake ◽  
The Impact

scholarly journals Comparison of root water uptake models in simulating CO<sub>2</sub> and H<sub>2</sub>O fluxes and growth of wheat

2020 ◽  
Vol 24 (10) ◽  
pp. 4943-4969
Author(s):  
Thuy Huu Nguyen ◽  
Matthias Langensiepen ◽  
Jan Vanderborght ◽  
Hubert Hüging ◽  
Cho Miltin Mboh ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Root Growth ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Coupled Model ◽  
Hydraulic Conductance ◽  
Root Water Uptake ◽  
Whole Plant ◽  
Hydraulic Signaling

Abstract. Stomatal regulation and whole plant hydraulic signaling affect water fluxes and stress in plants. Land surface models and crop models use a coupled photosynthesis–stomatal conductance modeling approach. Those models estimate the effect of soil water stress on stomatal conductance directly from soil water content or soil hydraulic potential without explicit representation of hydraulic signals between the soil and stomata. In order to explicitly represent stomatal regulation by soil water status as a function of the hydraulic signal and its relation to the whole plant hydraulic conductance, we coupled the crop model LINTULCC2 and the root growth model SLIMROOT with Couvreur's root water uptake model (RWU) and the HILLFLOW soil water balance model. Since plant hydraulic conductance depends on the plant development, this model coupling represents a two-way coupling between growth and plant hydraulics. To evaluate the advantage of considering plant hydraulic conductance and hydraulic signaling, we compared the performance of this newly coupled model with another commonly used approach that relates root water uptake and plant stress directly to the root zone water hydraulic potential (HILLFLOW with Feddes' RWU model). Simulations were compared with gas flux measurements and crop growth data from a wheat crop grown under three water supply regimes (sheltered, rainfed, and irrigated) and two soil types (stony and silty) in western Germany in 2016. The two models showed a relatively similar performance in the simulation of dry matter, leaf area index (LAI), root growth, RWU, gross assimilation rate, and soil water content. The Feddes model predicts more stress and less growth in the silty soil than in the stony soil, which is opposite to the observed growth. The Couvreur model better represents the difference in growth between the two soils and the different treatments. The newly coupled model (HILLFLOW–Couvreur's RWU–SLIMROOT–LINTULCC2) was also able to simulate the dynamics and magnitude of whole plant hydraulic conductance over the growing season. This demonstrates the importance of two-way feedbacks between growth and root water uptake for predicting the crop response to different soil water conditions in different soils. Our results suggest that a better representation of the effects of soil characteristics on root growth is needed for reliable estimations of root hydraulic conductance and gas fluxes, particularly in heterogeneous fields. The newly coupled soil–plant model marks a promising approach but requires further testing for other scenarios regarding crops, soil, and climate.

Tracing plant water fluxes in ecosystems by stable isotopes along the soil-plant and plant-atmosphere interfaces

2020 ◽  
Author(s):  
Christiane Werner
Keyword(s):  
Water Uptake ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Root Water Uptake ◽  
Plant Water ◽  
Water Fluxes ◽  
Terrestrial Vegetation ◽  
Species Specific ◽  
The Impact

&lt;p&gt;Terrestrial vegetation is a main driver of ecosystem water fluxes, as plants mediate the water fluxes within the soil-vegetation-atmosphere continuum. Stable isotopologues of water are efficient tracer to follow the water transfer in soils, uptake by plants, transport in stems and release into the atmosphere through stomata. The development of in-situ methods coupled to isotope spectroscopy does now enable real-time in-situ water vapour isotopologue measurements revealing high spatial and temporal dynamics, such as adaptations in root water uptake depths (within hours to days) or the impact of transpirational fluxes on atmospheric moisture.&lt;/p&gt;&lt;p&gt;Examples will be given how isotopes can be used to inform the complex interplay between plant ecophysiological adaptations and hydrological processes. For example, root water uptake is not solely driven by soil water availability but has to be understood in the context of species-specific regulation of active zones in their rooting system determining the conductivity between soil and roots regulating uptake depths. The latter has also to be evaluated in context of the nutrient demand and the spatial nutrient availability. Similarly, plant water transport and losses are a fined tuned interplay between species-specific structural and functional adaptations and atmospheric processes.&lt;/p&gt;&lt;p&gt;Finally, first data of a large-scale ecosystem labelling experiment at the Biosphere 2 tropical rainforest of the B2 Wald, Atmosphere, and Live Dynamics (B2WALD) will be presented.&lt;/p&gt;

scholarly journals Root distributions in a laboratory box evaluated using two different techniques (gravimetric and image processing) and their impact on root water uptake simulated with HYDRUS

2016 ◽  
Vol 64 (2) ◽  
pp. 196-208 ◽  
Author(s):  
Aleš Klement ◽  
Miroslav Fér ◽  
Šárka Novotná ◽  
Antonín Nikodem ◽  
Radka Kodešová
Keyword(s):  
Image Analysis ◽  
Water Uptake ◽  
Fine Roots ◽  
Root Zone ◽  
Root Water Uptake ◽  
Root Density ◽  
Gravimetric Analysis ◽  
Lower Root ◽  
The Impact ◽  
Hydrus 1D

Abstract Knowledge of the distribution of plant roots in a soil profile (i.e. root density) is needed when simulating root water uptake from soil. Therefore, this study focused on evaluating barley and wheat root densities in a sand-vermiculite substrate. Barley and wheat were planted in a flat laboratory box under greenhouse conditions. The box was always divided into two parts, where a single plant row and rows cross section (respectively) was simulated. Roots were excavated at the end of the experiment and root densities were assessed using root zone image processing and by weighing. For this purpose, the entire area (width of 40 and height of 50 cm) of each scenario was divided into 80 segments (area of 5×5 cm). Root density in each segment was expressed as a root percentage of the entire root cluster. Vertical root distributions (i.e. root density with respect to depth) were also calculated as a sum of root densities in each 5 cm layer. Resulting vertical root densities, measured evaporation from the water table (used as the potential root water uptake), and the Feddes stress response function model were used for simulating substrate water regime and actual root water uptake for all scenarios using HYDRUS-1D. All scenarios were also simulated using HYDRUS-2D. One scenario (areal root density of barley sown in a single row, obtained using image analysis) is presented in this paper (because most scenarios showed root water uptakes similar to results of 1D scenarios). The application of two root detecting techniques resulted in noticeably different root density distributions. Differences were mainly attributed to the fact that fine roots of high density (located mostly at the deeper part of the box) had lower weights in comparison to the weight of few large roots (at the box top). Thus, at the deeper part, higher root density (with respect to the entire root zone) was obtained using the image analysis in comparison to that from the gravimetric analysis. Conversely, lower root density was obtained using the image analysis at the upper part in comparison to that from the gravimetric analysis. On the other hand, fine roots overlapped each other and therefore were not visible in the image, which resulted in lower root density values from image analysis. Root water uptakes simulated with HYDRUS-1D using diverse root densities obtained for each cereal declined differently from the potential root water uptake values depending on water scarcity at depths of higher root density. Usually, an earlier downtrend associated with gradual root water up-take decreases and vice versa. Similar root water uptakes were simulated for the presented scenario using the HYDRUS-1D and HYDRUS-2D models. The impact of the horizontal root density distribution on root water uptake was, in this case, less important than the impact of the vertical root distribution resulting from different techniques and sowing scenarios.

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