Water Table Management for Upland Crops: A Theoretical Modelling Investigation

2012 ◽  
Author(s):  
Ayob Katimon
Keyword(s):  
Water Balance ◽  
Water Table ◽  
Root Zone ◽  
Theoretical Modelling ◽  
Balance Model ◽  
Practical Application ◽  
Local Data ◽  
Rice Farmers ◽  
Water Tables ◽  
Water Table Management

Kertas ini membincangkan beberapa aspek pengurusan paras air tanah untuk kegunaan tanaman ladang di kawasan sawah padi terbiar yang mempunyai paras tanah cetek. Oleh sebab tanaman ladang menjadi lebih penting kepada para petani sebagai sebahagian program mempelbagaikan tanaman, maka sokongan teknikal mengenai bagaimana sumber air ladang dapat dioptimumkan untuk tanaman amat diperlukan. Satu kajian teoriteknikal berdasarkan model imbangan air tanah pada ruang akar tanaman dan kesannya terhadap penyusutan paras air tanah telah dilakukan. Keputusan pemodelan digunakan untuk merancang kawalan paras air tanah yang sesuai kepada tanaman ladang. Aplikasi yang praktikal telah ditunjukkan dengan menggunakan beberapa data tempatan. Kata kunci: Paras air tanah, pengairan, tanaman ladang, imbangan air This study discusses some aspects of water table management for upland crops in the abandoned rice fields of shallow field water tables. As upland crops are gaining importance to rice farmers as part of the crop diversification programme, a technical support on how to manage the water resources optimally for plant growth would be extremely valuable. A theoretical investigation based on soil–water balance model in the root zone and water table draw–down is presented. The result is used to formulate the necessary water table control suitable for upland crops. A practical application is demonstrated by the translation of the concluding formula into a local data. Key words: Water table, irrigation, field crop, water balance

Development and application of long-term root zone salt balance model for predicting soil salinity in arid shallow water table area

2019 ◽  
Vol 213 ◽  
pp. 486-498 ◽  
Author(s):  
Guanfang Sun ◽  
Yan Zhu ◽  
Ming Ye ◽  
Jinzhong Yang ◽  
Zhongyi Qu ◽  
...  
Keyword(s):  
Shallow Water ◽  
Water Table ◽  
Soil Salinity ◽  
Root Zone ◽  
Balance Model ◽  
Salt Balance ◽  
Shallow Water Table

Estimating yield of sorghum using root zone water balance model and spectral characteristics of crop in a dryland Alfisol

2007 ◽  
Vol 87 (3) ◽  
pp. 315-327 ◽  
Author(s):  
Uttam Kumar Mandal ◽  
U.S. Victor ◽  
N.N. Srivastava ◽  
K.L. Sharma ◽  
V. Ramesh ◽  
...  
Keyword(s):  
Water Balance ◽  
Root Zone ◽  
Spectral Characteristics ◽  
Water Balance Model ◽  
Balance Model ◽  
Zone Water

scholarly journals Integration of vegetation indices into a water balance model to estimate evapotranspiration of wheat and corn

2010 ◽  
Vol 7 (5) ◽  
pp. 8631-8659
Author(s):  
F. L. M. Padilla ◽  
M. P. González-Dugo ◽  
P. Gavilán ◽  
J. Domínguez
Keyword(s):  
Water Stress ◽  
Water Balance ◽  
Root Zone ◽  
Vegetation Indices ◽  
Crop Coefficient ◽  
Grain Filling ◽  
Sensor Data ◽  
Balance Model ◽  
Plant Canopies ◽  
Negative Effect

Abstract. Vegetation indices (VIs) have been traditionally used for quantitative monitoring of vegetation. Remotely sensed radiometric measurements of visible and infrared solar energy, which is reflected or emitted by plant canopies, can be used to obtain rapid, non-destructive estimates of certain canopy attributes and parameters. One parameter of special interest for water management applications, is the crop coefficient employed by the FAO-56 model to derive actual crop evapotranspiration (ET). The aim of this study was to evaluate a methodology that combines the basal crop coefficient derived from VIs with a daily soil water balance in the root zone to estimate daily evapotranspiration rates for corn and wheat crops at field scale. The ability of the model to trace water stress in these crops was also assessed. Vegetation indices were first retrieved from field hand-held radiometer measurements and then from Landsat 5 and 7 satellite images. The results of the model were validated using two independent measurement systems for ET and regular soil moisture monitoring, in order to evaluate the behavior of the soil and atmosphere components of the model. ET estimates were compared with latent heat flux measured by an eddy covariance system and with weighing lysimeter measurements. Average overestimates of daily ET of 8 and 11% were obtained for corn and wheat, respectively, with good agreement between the estimated and measured root-zone water deficit for both crops when field radiometry was employed. Satellite remote-sensing inputs overestimated ET by 4 to 9%, showing a non-significant lost of accuracy when the satellite sensor data replaced the field radiometry data. The model was also used to monitor the water stress during the 2009 growing season, detecting several periods of water stress in both crops. Some of these stresses occurred during stages like grain filling, when the water stress is know to have a negative effect on yield. This fact could explain the lower yield reached compared to local yield statistics for wheat and corn. The results showed that the model can be used to calculate the water requirements of these crops in irrigated areas and that its ability to monitor water stress deserves further research.

scholarly journals Integration of vegetation indices into a water balance model to estimate evapotranspiration of wheat and corn

2011 ◽  
Vol 15 (4) ◽  
pp. 1213-1225 ◽  
Author(s):  
F. L. M. Padilla ◽  
M. P. González-Dugo ◽  
P. Gavilán ◽  
J. Domínguez
Keyword(s):  
Water Stress ◽  
Water Balance ◽  
Root Zone ◽  
Vegetation Indices ◽  
Crop Coefficient ◽  
Grain Filling ◽  
Sensor Data ◽  
Balance Model ◽  
Plant Canopies ◽  
Negative Effect

Abstract. Vegetation indices (VIs) have been traditionally used for quantitative monitoring of vegetation. Remotely sensed radiometric measurements of visible and infrared solar energy, which is reflected or emitted by plant canopies, can be used to obtain rapid, non-destructive estimates of certain canopy attributes and parameters. One parameter of special interest for water management applications, is the crop coefficient employed by the FAO-56 model to derive actual crop evapotranspiration (ET). The aim of this study was to evaluate a methodology that combines the basal crop coefficient derived from VIs with a daily soil water balance in the root zone to estimate daily evapotranspiration rates for corn and wheat crops at field scale. The ability of the model to trace water stress in these crops was also assessed. Vegetation indices were first retrieved from field hand-held radiometer measurements and then from Landsat 5 and 7 satellite images. The results of the model were validated using two independent measurement systems for ET and regular soil moisture monitoring, in order to evaluate the behavior of the soil and atmosphere components of the model. ET estimates were compared with latent heat flux measured by an eddy covariance system and with weighing lysimeter measurements. Average overestimates of daily ET of 8 and 11% were obtained for corn and wheat, respectively, with good agreement between the estimated and measured root-zone water deficit for both crops when field radiometry was employed. When the satellite sensor data replaced the field radiometry data the overestimation figures slightly changed to 9 and 6% for the same two crops. The model was also used to monitor the water stress during the 2009 growing season, detecting several periods of water stress in both crops. Some of these stresses occurred during stages like grain filling, when the water stress is know to have a negative effect on yield. This fact could explain the lower yield reached compared to local yield statistics for wheat and corn. The results showed that the model can be used to calculate the water requirements of these crops in irrigated areas and that its ability to monitor water stress deserves further research.

Effects of Temporary Water-tables on Marsh Grapefruit Trees in Sudan

1974 ◽  
Vol 10 (4) ◽  
pp. 247-250
Author(s):  
S. B. Abbadi ◽  
F. A. Minessy ◽  
A. T. Abdelhafeez
Keyword(s):  
Water Table ◽  
Root Zone ◽  
Soil Surface ◽  
Leaf Size ◽  
Size Number ◽  
Water Tables ◽  
Temporary Water ◽  
Moisture Characteristic ◽  
Number Of Leaves ◽  
Different Parts

SUMMARYTwo weeks after irrigation there was a temporary water-table between 30 and 127 cm. below the soil surface in four different parts of a grapefruit orchard. As the temporary water-table rose closer to the soil surface the percentage of soil water in the root zone increased and tree size, number of leaves per branch, and leaf size all decreased. Shallow water-tables also induced more die-back and reduced yields significantly. Analyses of soils at various sites indicated that there was no problem of salinity or alkalinity, but physical soil analyses showed that the percentage of clay increased with increased shallowness of the water-table, in line with the soil moisture characteristic curves.

scholarly journals SOIL-WATERGRIDS, mapping dynamic changes in soil moisture and depth of water table from 1970 to 2014

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Magda Guglielmo ◽  
Fiona H. M. Tang ◽  
Chiara Pasut ◽  
Federico Maggi
Keyword(s):  
Soil Moisture ◽  
Water Table ◽  
Root Zone ◽  
Water Saturation ◽  
Deep Soil ◽  
Dynamic Changes ◽  
Weather Patterns ◽  
Water Tables ◽  
Independent Observations

AbstractWe introduce here SOIL-WATERGRIDS, a new dataset of dynamic changes in soil moisture and depth of water table over 45 years from 1970 to 2014 globally resolved at 0.25 × 0.25 degree resolution (about 30 × 30 km at the equator) along a 56 m deep soil profile. SOIL-WATERGRIDS estimates were obtained using the BRTSim model instructed with globally gridded soil physical and hydraulic properties, land cover and use characteristics, and hydrometeorological variables to account for precipitation, ecosystem-specific evapotranspiration, snowmelt, surface runoff, and irrigation. We validate our estimates against independent observations and re-analyses of the soil moisture, water table depth, wetland occurrence, and runoff. SOIL-WATERGRIDS brings into a single product the monthly mean water saturation at three depths in the root zone and the depth of the highest and lowest water tables throughout the reference period, their long-term monthly averages, and data quality. SOIL-WATERGRIDS can therefore be used to analyse trends in water availability for agricultural abstraction, assess the water balance under historical weather patterns, and identify water stress in sensitive managed and unmanaged ecosystems.

Water balance of three irrigated crops on fine-textured soils of the Riverine Plain

1983 ◽  
Vol 34 (2) ◽  
pp. 183 ◽  
Author(s):  
WK Mason ◽  
WS Meyer ◽  
RCG Smith ◽  
HD Barrs
Keyword(s):  
Water Balance ◽  
Water Use ◽  
Water Table ◽  
Root Length Density ◽  
Capillary Rise ◽  
Water Balance Model ◽  
Balance Model ◽  
Available Water ◽  
Eastern Australia ◽  
Plant Available Water

Three summer crop species, maize, sorghum and sunflower were grown on three different fine-textured soils of the Riverine Plain in south-eastern Australia. At each site, above-ground growth, phenological development, and root length density were measured in two well-watered plots. Water use, plant water status and final crop yield were measured in the well-watered plots and in one plot per site where irrigation was discontinued around the time that complete crop canopies had developed. Plant available water was estimated from these drying-cycle plots. Crop water use calculated from soil water contents did not agree with estimates from a water balance model at two of the sites, suggesting that capillary rise from shallow water tables was supplying considerable quantities of water to the crops. Using the water balance model to predict actual evapotranspiration (Et), we estimated that after complete canopy development, up to 40% of Et was supplied to well-watered crops from a water table at approximately 1.5 m. At the site without a water table, yields from the drying-cycle plots were severely reduced and the estimate of plant available water (PAW) was thought to be realistic. It was concluded that where capillary rise or lateral movement of water into the root zone was significant, the concept of plant available water (PAW) was unsatisfactory.

Characterizing water use by irrigated wheat at Griffith, New South Wales

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 499 ◽  
Author(s):  
WS Meyer ◽  
FX Dunin ◽  
RCG Smith ◽  
GSG Shell ◽  
NS White
Keyword(s):  
Water Use ◽  
Field Experiments ◽  
Root Zone ◽  
Soil Surface ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Wheat Crop ◽  
Water Tables ◽  
Irrigated Wheat ◽  
Upward Flux

Wheat is being grown increasingly in the irrigated areas of south-east Australia. Its profitability depends on high yields, which in turn, are highly dependent on accurate water management. This combination, together with the increasing need for greater water use efficiency to minimize accessions to rising water-tables, calls for effective irrigation scheduling. To achieve this, accurate estimates of crop water use and upward fluxes of water into the root zone from shallow water-tables are required. A weighing lysimeter, installed in 1984, measured hourly evaporation (Ea) from a wheat crop which enabled the accuracy of water use estimates to be assessed. Daily potential evaporation (Ep) was calculated from a combination equation previously calibrated over lucerne, while previously developed crop coefficients for wheat were used to convert Ep to estimated Ea. Daily Ea was the major component in a water balance model for irrigated wheat. The model was quite efficient (r2 = 0.911, but with a bias of -8.8%, which indicated that Ea values were generally underestimated. The underestimate was due primarily to the wind function used in the calculation of Ep, and alternative functions for both daily and hourly calculations were derived. The 1984 lysimeter data also showed that change in soil water content was accurately measured with the field-calibrated neutron probe. Comparisons of measured and estimated water use from field experiments in 1981 and 1982 indicated that upward flux from a water-table between 1 a5 and 2.1 m below the soil surface may be up to 30% of daily Ea. This upward flux will need to be taken into account if irrigation scheduling is to promote efficient use of irrigation water.

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