Use of limited soil property data and modeling to estimate root zone soil water content

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.

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A MODEL FOR ESTIMATING ACTUAL EVAPOTRANSPIRATION FROM POTENTIAL EVAPOTRANSPIRATION

Hydrology Research ◽

10.2166/nh.1975.0012 ◽

1975 ◽

Vol 6 (3) ◽

pp. 170-188 ◽

Cited By ~ 212

Author(s):

K. J. KRISTENSEN ◽

S. E. JENSEN

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Root Zone ◽

Potential Evapotranspiration ◽

Actual Evapotranspiration ◽

Vegetation Density ◽

Rainfall Distribution ◽

Sugar Beets

A model for calculating the daily actual evapotranspiration based on the potential one is presented. The potential evapotranspiration is reduced according to vegetation density, water content in the root zone, and the rainfall distribution. The model is tested by comparing measured (EAm) and calculated (EAc) evapotranspirations from barley, fodder sugar beets, and grass over a four year period. The measured and calculated values agree within 10 %. The model also yields information on soil water content and runoff from the root zone.

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The Effect of Dry Pegging Zone Soil on Pod Formation of Florunner Peanut1

Peanut Science ◽

10.3146/i0095-3679-24-1-6 ◽

1997 ◽

Vol 24 (1) ◽

pp. 19-24 ◽

Cited By ~ 6

Author(s):

P. J. Sexton ◽

J. M. Bennett ◽

K. J. Boote

Keyword(s):

Drought Stress ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Deficit ◽

Growth Rates ◽

Root Zone ◽

Soil Water Deficit ◽

Seed Growth ◽

Pod Development

Abstract Peanut (Arachis hypogaea L.) fruit growth is sensitive to surface soil (0-5 cm) conditions due to its subterranean fruiting habit. This study was conducted to determine the effect of soil water content in the pegging zone (0-5 cm) on peanut pod growth rate and development. A pegging-pan-root-tube apparatus was used to separately control soil water content in the pegging and root zone for greenhouse trials. A field study also was conducted using portable rainout shelters to create a soil water deficit. Pod phenology, pod and seed growth rates, and final pod and seed dry weights were determined. In greenhouse studies, dry pegging zone soil delayed pod and seed development. In the field, soil water deficits in the pegging and root zone decreased pod and seed growth rates by approximately 30% and decreased weight per seed from 563 to 428 mg. Pegs initiating growth during drought stress demonstrated an ability to suspend development during the period of soil water deficit and to re-initiate pod development after the drought stress was relieved.

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Effects of Typical Chemical Agents on Preventing Pollution and Controlling Drought in a Cherry Orchard

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.1340 ◽

2012 ◽

Vol 550-553 ◽

pp. 1340-1344

Author(s):

Ren Kuan Liao ◽

Pei Ling Yang ◽

Shu Mei Ren ◽

Hang Yi ◽

Long Wang ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

North China Plain ◽

North China ◽

Root Zone ◽

Soil Layer ◽

The North ◽

The North China Plain ◽

Chemical Agents

In the North China plain, serious Non-point-source (NPS) pollution and drought are two great concerns in agricultural production. In our studies, two typical chemical agents ( SAP and FA ) were selected to control drought and pollution in a cheery orchard. Soil water content, nutrient transport in soil profile have been researched. The results showed that the soil water content of treatments with chemical agents increased maximally by 19.4% relative to treatment without chemical agents, and increased by 35.2% for Ammonium-N in 20-60 cm soil layer ( main root zone ). However, in 60-120 cm deeper soil layer, the water leakage of treatments with chemical agents decreased averagely by 15.1% relative to treatment without chemical agents, and increased by 43.8% for Nitrate-N. The chemical agents hold water and nutrient in root zone and thus reducing the risk of pollutant leaching into the underground water. It can be found that treatment ( 150kg/h㎡ SAP + 300 times FA ) is the optimal combination group in all treatments. The chemical prevention technology provided a new guide for controlling drought and reducing NPS pollution in cherry planting in the North China plain.

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

Soil Research ◽

10.1071/sr07116 ◽

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.

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Using monitoring data of surface soil to predict whole crop-root zone soil water content with PSO-LSSVM, GRNN and WNN

Earth Science Informatics ◽

10.1007/s12145-013-0130-6 ◽

2013 ◽

Vol 7 (1) ◽

pp. 59-68 ◽

Cited By ~ 1

Author(s):

Zhao Lixi ◽

Shui Pengbo ◽

Jiang Fang ◽

Qiu Hengqing ◽

Ren Shumei ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Surface Soil ◽

Root Zone ◽

Monitoring Data ◽

Crop Root

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Evaluating Soil Water Content in a WRF-Noah Downscaling Experiment

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-12-0239.1 ◽

2013 ◽

Vol 52 (10) ◽

pp. 2312-2327 ◽

Cited By ~ 22

Author(s):

Peter Greve ◽

Kirsten Warrach-Sagi ◽

Volker Wulfmeyer

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Land Surface ◽

Root Zone ◽

Regional Scale ◽

Land Surface Model ◽

Surface Model ◽

Flux Partitioning

AbstractSoil water content (SWC) depends on and affects the energy flux partitioning at the land–atmosphere interface. Above all, the latent heat flux is limited by the SWC of the root zone on one hand and radiation on the other. Therefore, SWC is a key variable in the climate system. In this study, the performance of the Weather Research and Forecasting model coupled with the Noah land surface model (WRF-Noah) system in a climate hindcast simulation from 1990 to 2008 is evaluated with respect to SWC versus two reanalysis datasets for Europe during 2007 and 2008 with in situ soil moisture observations from southern France. When compared with the in situ observations, WRF-Noah generally reproduces the SWC annual cycle while the reanalysis SWCs do not. The biases in areal mean WRF-Noah SWCs relate to biases in precipitation and evapotranspiration in a cropland environment. The spatial patterns and temporal variability of the seasonal mean SWCs from the WRF-Noah simulations and from the two reanalyses correspond well, while absolute values differ significantly, especially at the regional scale.

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Spatial Root Zone Soil Water Content Estimation in Agricultural Lands Using Bayesian-Based Artificial Neural Networks and High- Resolution Visual, NIR, and Thermal Imagery

Irrigation and Drainage ◽

10.1002/ird.2098 ◽

2017 ◽

Vol 66 (2) ◽

pp. 273-288 ◽

Cited By ~ 11

Author(s):

Leila Hassan-Esfahani ◽

Alfonso Torres-Rua ◽

Austin Jensen ◽

Mac Mckee

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

High Resolution ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Root Zone ◽

Agricultural Lands ◽

Thermal Imagery ◽

Artificial Neural

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Simulation of soil water content on a small reclaimed watershed in northern Alberta using the Root Zone Water Quality Model (RZQWM)

Canadian Journal of Soil Science ◽

10.4141/s05-056 ◽

2006 ◽

Vol 86 (4) ◽

pp. 675-690 ◽

Cited By ~ 4

Author(s):

E. Mapfumo ◽

D S Chanasyk ◽

C. L.A. Chaikowsky

Keyword(s):

Water Quality ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Model Evaluation ◽

Root Zone ◽

Weather Data ◽

Quality Model ◽

D Values ◽

Zone Water

A study was conducted at Syncrude Canada Ltd., Alberta, to evaluate the simulation of soil volumetric water content from the reclaimed slopes of the Southwest Sand Storage Facility using the Root Zone Water Quality Model (RZWQM). Soil water content measurements were conducted every 2 wk using a neutron moisture meter in 2001 (dry year) and 2002 (wet year). Two types of calibration and evaluation were performed: first, calibration using 2001 weather data (dry year) and evaluation using 2002 weather data (wet year) (herein referred to as method 1); second, calibration using 2002 weather data (wet year) and evaluation using 2001 weather data (dry year) herein referred to as (method 2). Results from the method 1 calibration for each tube indicated modeling efficiencies (EF) between −0.27 and 0.90, coefficients of determination (r2) between 0.13 and 0.97, and deviation (D, as %) of simulated from measured values of less than 5%. The model evaluation by tube location following method 1 calibration indicated EF values between −3.80 and 0.56, whereas r2 values ranged between 0.08 and 0.82. Although five out of eight tubes had D values > 5%, all except for one tube had D values < 20%. Method 2 calibration results for each tube indicated EF values of −0.34 to 0.85, r2 values of 0.07 to 0.85 and all D values < 5%. Results of the method 2 model evaluation by tube location indicated EF values of −10.15 to 0.75 (overall EF = −0.84), r2 values of 0.04 to 0.96 (overall r2 = 0.39) and D values of 2.6 to 48.6% (overall D = 19.8). Method 2 model evaluation results indicated EF values of −1.69, −3.85 and −0.01, for depths of 15, 25 and 35 cm, respectively. The D values were 27, 20 and 13%, respectively. Graphical displays indicated that during the evaluation process, the model generally tended to slightly under-estimate the wetter moisture conditions, regardless of whether data for a wet year or a dry year were used during the calibration process. Key words: Modeling, calibration method, soil water, land reclamation

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

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2760 ◽

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.

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