Modelling water uptake by a mature apple tree

Soil Research ◽  
2003 ◽  
Vol 41 (3) ◽  
pp. 365 ◽  
Author(s):  
S. R. Green ◽  
I. Vogeler ◽  
B. E. Clothier ◽  
T. M. Mills ◽  
C. van den Dijssel
Keyword(s):  
Experimental Data ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Apple Tree ◽  
Water Movement ◽  
Root Zone ◽  
Time Domain Reflectometry ◽  
Richards Equation ◽  
Mature Apple

We report the results from a field experiment in which we examined the spatial and temporal patterns of water uptake by a mature apple tree (Malus domestica Borkh., 'Splendour') in an orchard. Time domain reflectometry was used to measure changes in the soil's volumetric water content, and heat-pulse was used to monitor locally the rates of sap flow in the trunk and roots of the tree. The tree's distribution of root-length density and supporting data to characterise the soil's hydraulic properties were determined for the purpose of modelling soil water movement in the root-zone under an apple tree. Experimental data are compared against the output from a numerical model of the soil water balance that uses Richards' equation for water flow, and uses a distributed macroscopic sink term for root uptake. In general, there was a very good agreement between the measured and modelled results. The apple trees consumed some 70 L of water per day during the middle of summer. The daily water use declined to about 20 L per day with the onset of autumn, coinciding with a reduced evaporative demand and an increasing number of rain days. Water movement in the root-zone soil was dominated by the water uptake via surface roots. Large changes in soil water content were also associated with each irrigation event. Our experimental data support the contention that more frequent irrigation in smaller doses will result in less water percolating through the root-zone. Such an irrigation strategy should make more efficient use of water by minimising the leaching losses. It will also be helpful for environmental protection by reducing the percolation losses of water and solute beyond the grasp of the roots.

scholarly journals Modelling the Impact on Root Water Uptake and Solute Return Flow of Different Drip Irrigation Regimes with Brackish Water

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 425 ◽  
Author(s):  
Fairouz Slama ◽  
Nessrine Zemni ◽  
Fethi Bouksila ◽  
Roberto De Mascellis ◽  
Rachida Bouhlila
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Uptake ◽  
Brackish Water ◽  
Deficit Irrigation ◽  
Root Zone ◽  
Root Water Uptake ◽  
Return Flows ◽  
Semi Arid

Water scarcity and quality degradation represent real threats to economic, social, and environmental development of arid and semi-arid regions. Drip irrigation associated to Deficit Irrigation (DI) has been investigated as a water saving technique. Yet its environmental impacts on soil and groundwater need to be gone into in depth especially when using brackish irrigation water. Soil water content and salinity were monitored in a fully drip irrigated potato plot with brackish water (4.45 dSm−1) in semi-arid Tunisia. The HYDRUS-1D model was used to investigate the effects of different irrigation regimes (deficit irrigation (T1R, 70% ETc), full irrigation (T2R, 100% ETc), and farmer’s schedule (T3R, 237% ETc) on root water uptake, root zone salinity, and solute return flows to groundwater. The simulated values of soil water content (θ) and electrical conductivity of soil solution (ECsw) were in good agreement with the observation values, as indicated by mean RMSE values (≤0.008 m3·m−3, and ≤0.28 dSm−1 for soil water content and ECsw respectively). The results of the different simulation treatments showed that relative yield accounted for 54%, 70%, and 85.5% of the potential maximal value when both water and solute stress were considered for deficit, full. and farmer’s irrigation, respectively. Root zone salinity was the lowest and root water uptake was the same with and without solute stress for the treatment corresponding to the farmer’s irrigation schedule (273% ETc). Solute return flows reaching the groundwater were the highest for T3R after two subsequent rainfall seasons. Beyond the water efficiency of DI with brackish water, long term studies need to focus on its impact on soil and groundwater salinization risks under changing climate conditions.

Water drawdown by radish (Raphanus sativus L.) multiple-root systems evaluated using computed tomography

Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 228
Author(s):  
M. A. Hamza ◽  
S. H. Anderson ◽  
L. A. G. Aylmore
Keyword(s):  
Computed Tomography ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Uptake ◽  
Root Zone ◽  
Multiple Root ◽  
Root Systems ◽  
Bulk Soil ◽  
Water Drawdown

Although measurements of water drawdown by single radish root systems have been previously published by the authors, further research is needed to evaluate water drawdown patterns in multiple-root systems. The objective of this study was to compare water transpiration patterns estimated using X-ray computed tomography (CT) with the traditional gravimetric method and to evaluate the effects of variably spaced multiple root systems on soil water content and corresponding water content gradients. Water drawdown showed a dual pattern in which it increased rapidly when soil water content was high at the beginning of transpiration, then slowed down to an almost constant level with time as water content decreased. These results contrast with the single-root system wherein transpiration rates initially increased rapidly and then slowly increased with time. Water uptake estimated using the CT method was observed to be 27–38% lower than the gravimetrically estimated water uptake; this difference was attributed to lower water uptake for the upper 30 mm layer (CT measured) than lower layers due to differences in root density. However, good correlation (r = 0.97) was found between both measurement methods. The drawdown patterns for multiple root systems showed a convex shape from the root surface to the bulk soil, compared with a nearly linear shape for single roots. The water content drawdown areas and the drawdown distances for multiple root systems were found to be much larger than those corresponding to single radish roots. Differential water content gradients were observed for roots spaced at 15-mm distances compared with 3–4-mm distances. These differential gradients from the bulk soil towards the root-zone occurred probably creating localised water potential gradients within the root-zone, which moved water from between roots to root surfaces. The lowest water content values were located in the inter-root areas. The CT-scanned layer probably acted as one drawdown area with particularly higher water drawdown from the inter-root areas.

scholarly journals Soil water-balance-based approach for estimating percolation with lysimeter and in field with and without mulch under micro irrigation

2021 ◽  
Vol 16 (5) ◽  
pp. 1-12
Author(s):  
Eugênio Ferreira Coelho ◽  
Marcos de Souza Campos ◽  
Marcelo Rocha dos Santos ◽  
Rafael Dreux Miranda Fernandes ◽  
Jailson Lopes Cruz
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Zone ◽  
Sprinkler Irrigation ◽  
Time Domain Reflectometry ◽  
Soil Water Balance ◽  
Time Intervals ◽  
Reliable Determination

Precise, accurate knowledge of percolation is key to reliable determination of soil water balance and a crop’s water-use efficiency. This work evaluated an approach to estimate the amount of water percolated in the root zone using soil water content (SWC) data measured at different time intervals. The approach was based on the difference of soil water content within and below the effective root zone of banana plants at different time intervals. A drainage lysimeter was used to compare the measured and estimated percolation data. The approach was then used in a banana orchard under drip and micro sprinkler irrigation, with and without the use of mulch. The soil water storage in the banana’s root zone was evaluated within a two-dimensional soil profile with time domain reflectometry (TDR). Mean percolation measured in the lysimeters did not differ from the approach’s estimates using intervals between SWC readings equal to or longer than 6 h from the end of an irrigation event. Percolation estimates under drip and micro sprinkler irrigation in the field, with and without mulch, were consistent with those measured in the lysimeters, considering the 6-h interval of SWC measurements. Percolation was greater under the drip irrigation system with mulch. The amount of water percolated was not influenced by the presence of mulch under the micro sprinkler system. Keywords: localized irrigation, soil water balance, soil water content sensor.

scholarly journals Soil Water Studies on Oxisols and Ultisols of Puerto Rico: III. Capillary Conductivity

1969 ◽  
Vol 60 (4) ◽  
pp. 508-512
Author(s):  
James M. Wolf ◽  
Matthew Drosdoff
Keyword(s):  
Puerto Rico ◽  
Water Content ◽  
Soil Water ◽  
Water Movement ◽  
Root Zone

Values of capillary conductivity were calculated for the Humatas and Bayamón soils. These were found to be highly water content dependent. Using values of capillary conductivity, it was estimated that 10% of the water required for evapotranspiration might be supplied by upward water movement from the profile below the root zone.

scholarly journals Using the sensitivity of biomass production to soil water for physiological drought evaluation

2008 ◽  
Vol 3 (Special Issue No. 1) ◽  
pp. S116-S122 ◽  
Author(s):  
V. Novák
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Biomass Production ◽  
Transpiration Rate ◽  
Water Movement ◽  
Root Zone ◽  
Vegetation Period ◽  
Plant Production ◽  
Potential Transpiration

The analysis of drought as a phenomenon and the proposal of how to define and quantify the deficiency of water in soil for plants, so called physiological drought, are described. The presented approach is based on the theoretical considerations supported by empirically estimated relationships between the biomass production of a particular plant and the transpiration total of this plant during its vegetation period. This relationship is linear and is valid for particular plant and environmental conditions (nutrition, agrotechnics). Optimal plant production can be reached for maximum seasonal transpiration total, therefore the potential transpiration total corresponds to the maximum possible yield. The transpiration rate lower than the potential one leads to a biomass production decrease. This phenomenon can be used to define the physiological drought, under which the soil water content in the root zone decreases below the so called critical soil water content of limited availability for plants, under which the transpiration rate drops below its potential transpiration rate. Methodology is illustrated on the basis of the results of mathematical modelling of soil water movement in Soil – Plant – Atmosphere system, with loamy soil and maize canopy.

scholarly journals Soil moisture monitoring in the Toce valley (Italy)

2003 ◽  
Vol 7 (6) ◽  
pp. 890-902 ◽  
Author(s):  
M. Menziani ◽  
S. Pugnaghi ◽  
S. Vincenzi ◽  
R. Santangelo
Keyword(s):  
Mass Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Time Domain ◽  
Heavy Precipitation ◽  
Time Domain Reflectometry ◽  
Balance Method ◽  
Richards Equation ◽  
Mass Balance Method

Abstract. In the framework of the Mesoscale Alpine Programme (MAP), soil water content profiles were collected at a point station in the Toce Valley (Lago Maggiore MAP Target Area). The data are for the first 70 cm depth of soil for the period April–November, 1999. All measurements were made by a Time Domain Reflectometry device. The time variation of the water stored in a column of soil was estimated by a mass balance method. Evaporation was estimated from the data collected in the summer period. Likewise, by applying the mass balance method to the data collected during and after heavy precipitation events, the water infiltrated into the soil was also estimated. A qualitative evaluation of ponding and/or runoff as the difference between the precipitated and the drained water was obtained under suitable assumptions. Furthermore, the time evolution of the soil water content profile was studied by solving the Richards equation both analytically and numerically for two particular cases: the driest period and a period following a heavy precipitation event. Finally, during the MAP Special Observing Period, two intensive campaigns were performed, together with measurements using an airborne passive microwave radiometer, to assess the spatial distribution of the surface (0–30 cm depth) soil water content in fields with different physical and agricultural characteristics. Keywords: soil water content, Time Domain Reflectometry, TDR temperature-dependence, evaporation, infiltration, runoff, linearised Richards equation.

scholarly journals Soil hydraulic material properties and layered architecture from time-lapse GPR

2018 ◽  
Vol 22 (4) ◽  
pp. 2551-2573 ◽  
Author(s):  
Stefan Jaumann ◽  
Kurt Roth
Keyword(s):  
Soil Water ◽  
Material Properties ◽  
Simulated Annealing Algorithm ◽  
Water Movement ◽  
Time Domain Reflectometry ◽  
Groundwater Table ◽  
Richards Equation ◽  
Ground Truth Data ◽  
Marquardt Algorithm ◽  
Soil Hydraulic

Abstract. Quantitative knowledge of the subsurface material distribution and its effective soil hydraulic material properties is essential to predict soil water movement. Ground-penetrating radar (GPR) is a noninvasive and nondestructive geophysical measurement method that is suitable to monitor hydraulic processes. Previous studies showed that the GPR signal from a fluctuating groundwater table is sensitive to the soil water characteristic and the hydraulic conductivity function. In this work, we show that the GPR signal originating from both the subsurface architecture and the fluctuating groundwater table is suitable to estimate the position of layers within the subsurface architecture together with the associated effective soil hydraulic material properties with inversion methods. To that end, we parameterize the subsurface architecture, solve the Richards equation, convert the resulting water content to relative permittivity with the complex refractive index model (CRIM), and solve Maxwell's equations numerically. In order to analyze the GPR signal, we implemented a new heuristic algorithm that detects relevant signals in the radargram (events) and extracts the corresponding signal travel time and amplitude. This algorithm is applied to simulated as well as measured radargrams and the detected events are associated automatically. Using events instead of the full wave regularizes the inversion focussing on the relevant measurement signal. For optimization, we use a global–local approach with preconditioning. Starting from an ensemble of initial parameter sets drawn with a Latin hypercube algorithm, we sequentially couple a simulated annealing algorithm with a Levenberg–Marquardt algorithm. The method is applied to synthetic as well as measured data from the ASSESS test site. We show that the method yields reasonable estimates for the position of the layers as well as for the soil hydraulic material properties by comparing the results to references derived from ground truth data as well as from time domain reflectometry (TDR).

scholarly journals Drip Irrigation Management by TDR Monitoring of Soil Water and Solute Distribution

1993 ◽  
Author(s):  
Shmuel Dasberg ◽  
Jan W. Hopmans ◽  
Larry J. Schwankl ◽  
Dani Or
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Drip Irrigation ◽  
Water Distribution ◽  
Irrigation Management ◽  
Small Diameter ◽  
High Water ◽  
Time Domain Reflectometry ◽  
Parametric Modelling

Drip irrigation has the potential of high water use efficiency, but actual water measurement is difficult because of the limited wetted volume. Two long-term experiments in orchards in Israel and in California and several field crop studies supported by this project have demonstrated the feasibility of precise monitoring of soil water distribution for drip irrigation in spite of the limited soil wetting. Time Domain Reflectometry (TDR) enables in situ measurement of soil water content of well defined small volumes. Several approaches were tried in monitoring the soil water balance in the field during drip irrigation. These also facilitated the estimation of water uptake: 1. The use of multilevel moisture probe TDR system. This approach proved to be of limited value because of the extremely small diameter of measurement. 2. The placement of 20 cm long TDR probes at predetermined distances from the drippers in citrus orchards. 3. Heavy instrumentation with neutron scattering access tubes and tensiometers of a single drip irrigated almond tree. 4. High resolution spatial and temporal measurements (0.1m x 0.1m grid) of water content by TDR in corn irrigated by surface and subsurface drip. The latter approach was accompanied by parametric modelling of water uptake intensity patterns by corn roots and superimposed with analytical solutions for water flow from point and line sources. All this lead to general and physically based suggestions for the placement of soil water sensors for scheduling drip irrigation.

scholarly journals Soil hydraulic material properties and subsurface architecture from time-lapse GPR

2017 ◽  
Author(s):  
Stefan Jaumann ◽  
Kurt Roth
Keyword(s):  
Soil Water ◽  
Material Properties ◽  
Simulated Annealing Algorithm ◽  
Water Movement ◽  
Ground Truth ◽  
Time Domain Reflectometry ◽  
Richards Equation ◽  
Ground Truth Data ◽  
Marquardt Algorithm ◽  
Soil Hydraulic

Abstract. Quantitative knowledge of effective soil hydraulic material properties is essential to predict soil water movement. Ground-penetrating radar (GPR) is a non-invasive and non-destructive geophysical measurement method to monitor the hydraulic processes precisely. Previous studies showed that the GPR signal from a fluctuating groundwater table is sensitive to the soil water characteristic and the hydraulic conductivity function. In this work, we show that this signal is suitable to accurately estimate the subsurface architecture and the associated effective soil hydraulic material properties with inversion methods. Therefore, we parameterize the subsurface architecture, solve the Richards equation, convert the resulting water content to relative permittivity with the complex reflective index model (CRIM), and solve Maxwell's equations numerically. In order to analyze the GPR signal, we implemented a new heuristic event detection and association algorithm. Using events instead of the full wave regularizes the inversion as it allows to focus on the relevant measurement signal. Starting from an ensemble of Latin hypercube drawn initial parameter sets, we sequentially couple the simulated annealing algorithm with the Levenberg–Marquardt algorithm. We apply the method to synthetic as well as measured data from the ASSESS test site and show that the method yields accurate estimates for the soil hydraulic material properties as well as for the subsurface architecture by comparing the results to references derived from time domain reflectometry (TDR) and subsurface architecture ground truth data.

scholarly journals Simulation of palm oil root water uptake by using 2D numerical soil-water flow model.

2021 ◽  
Vol 9 (1) ◽  
pp. 31-40
Author(s):  
Lisma Safitri ◽  
Andiko Putro Suryotomo ◽  
Satyanto Krido Saptomo
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Flow ◽  
Water Uptake ◽  
Palm Oil ◽  
Oil Palm ◽  
Root Zone ◽  
Root Water Uptake ◽  
Palm Tree ◽  
Soil Water Flow

The lack of water resource in these past decades encourages the implementation of the precision agriculture system towards the sustainability in palm oil plantation. Therefore, it requires a specific information about the palm oil performance regarding the water balance system that affect the water consumption through the plant root water uptake. However, the prediction of root water uptake distribution is still a challenge. Another method to investigate the soil water dynamics under the plant root system is through the numerical simulations that are widely use to assess the soil water flow of the plant. In alignment with the idea of promoting the sustainable palm oil plantation, the investigation of root water uptake and water content under oil palm tree is highly demanding. As an introduction, through this study, it is find of interest to simulate the root water uptake and water content pattern of oil palm tree using the 2D simulation soil-water flow.  The study was performed by applying the 2D simulation soil-water flow model to 17th year old oil palm tree located in Siak, Riau with the loam soil type. The climate data was used as primary data to predict the rate of evapotranspiration. The soil properties and root dimension and distribution of oil palm was taken by the literature study. The simulation over 30 days illustrated the root water uptake distribution, water content change, pressure head and flow velocity. The most intensive root water uptake occurred in the upper root zone of oil palm tree as an impact of the higher root density. The significant root water uptake in the upper root zone lead to the decreasing of water content and increasing of pressure head in the soil.  Consequently, there was a change of water flow direction from the wet area in the downward and sideward do dry root zone as the water supply to the oil palm tree.  

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