scholarly journals Soil Water Uptake Patterns of Pecan Trees Grown in Coarse Gravelly Soils

1999 ◽  
Vol 9 (3) ◽  
pp. 402-408 ◽  
Author(s):  
Ronald B. Sorensen ◽  
Tim L. Jones
Keyword(s):  
Soil Water ◽  
Water Table ◽  
Water Uptake ◽  
Deep Water ◽  
Root Zone ◽  
Soil Depth ◽  
High Water ◽  
Neutron Probe ◽  
Uptake Pattern ◽  
Gravelly Soils

Soil depth for water uptake in pecan trees [Carya illinoensis (Wangenh.) C. Koch `Western Schley'] is considered to be <100 cm (3.2 ft) for sites that have high water tables. The objective of this research was to determine the water uptake pattern of pecan trees grown on sites with a deep water table [>30 m (100 ft)] and irrigated at 50 kPa (0.5 bar). Trees (15- to 20-year-old trunks) were transplanted into laser-leveled terraces in 1986. Two terraces (T) were selected and irrigated (1994 and 1995) at 50 kPa (T5) and farmer controlled [T6, weekly at ≈30 kPa (0.3 bar)]. Soil water content was measured on a 1.3 by 1.3 m (4 ft by 4 ft) grid for one tree in each terrace using a neutron probe. In 1994, the average soil depth for water uptake was 75 (2.5 ft) and 62 cm (2.0 ft) for T5 and T6 respectively. In 1995, the average soil depth for water uptake was 150 cm (5 ft) on T5 and 130 cm (4 ft) on T6. The total quantity of water removed below 140 cm (4.6 ft) soil depth was minor (<15%) when compared with the total water removed between 0 and 140 cm depth. T5 showed a deeper (260 cm; 8.5 ft) and wider (3.0 to 5.0 m; 10 to 16 ft) water uptake pattern compared with T6. Thus, pecan trees growing on these coarse soils with a deep water table and irrigated at 50 kPa have an effective root zone of ≈140 to 150 cm (4.6 to 5.0 ft).

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.

scholarly journals Water and salt transport in daily irrigated root zone.

1987 ◽  
Vol 35 (3) ◽  
pp. 395-406
Author(s):  
C. Dirksen
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Gamma Ray ◽  
Root Zone ◽  
Root Water Uptake ◽  
Salt Transport ◽  
Soil Water Retention ◽  
Transport Models ◽  
Leaching Fraction ◽  
Water Contents

With closed, high-frequency irrigation systems, the water supply can be tailored to the instant needs of plants. To be able to do this optimally, it is necessary to understand how plants interact with their environment. To study water uptake under a variety of non-uniform conditions in the root zone, lucerne was grown in laboratory soil columns with automated gamma ray attenuation, tensiometer and salinity sensor equipment to measure soil water contents, pressure potentials and osmotic potentials, respectively. The columns were irrigated with water of different salinity at various frequencies and leaching fractions. This paper presents results obtained in a column irrigated daily with water of conductivity 0.33 S/m (h0 = -13.2 m) at a target leaching fraction of 0.08. This includes the drying and wetting patterns under daily irrigations in deficit and excess of evapotranspiration, respectively. After 230 days the salination of the column had still not reached a steady state. Salinity increased rapidly with depth and root water uptake was shallow for the deep-rooting lucerne. Water and salt transport under daily irrigation cannot be described without taking hysteresis of soil water retention into account. The data presented are suitable for testing various water uptake models, once numerical water and salt transport models of the required complexity are operational. (Abstract retrieved from CAB Abstracts by CABI’s permission)

A regionally explicit, global SWI calibration based on ISMN observations

2021 ◽  
Author(s):  
Manolis G. Grillakis
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Large Scale ◽  
Root Zone ◽  
Soil Depth ◽  
European Space Agency ◽  
Soil Layer ◽  
Added Value ◽  
Water Index ◽  
Soil Moisture Data

&lt;p&gt;Remote sensing has proven to be an irreplaceable tool for monitoring soil moisture. The European Space Agency (ESA), through the Climate Change Initiative (CCI), has provided one of the most substantial contributions in the soil water monitoring, with almost 4 decades of global satellite derived and homogenized soil moisture data for the uppermost soil layer. Yet, due to the inherent limitations of many of the remote sensors, only a limited soil depth can be monitored. To enable the assessment of the deeper soil layer moisture from surface remotely sensed products, the Soil Water Index (SWI) has been established as a convolutive transformation of the surface soil moisture estimation, under the assumption of uniform hydraulic conductivity and the absence of transpiration. The SWI uses a single calibration parameter, the T-value, to modify its response over time.&lt;/p&gt;&lt;p&gt;Here the Soil Water Index (SWI) is calibrated using ESA CCI soil moisture against in situ observations from the International Soil Moisture Network and then use Artificial Neural Networks (ANNs) to find the best physical soil, climate, and vegetation descriptors at a global scale to regionalize the calibration of the T-value. The calibration is then used to assess a root zone related soil moisture for the period 2001 &amp;#8211; 2018.&lt;/p&gt;&lt;p&gt;The results are compared against the European Centre for Medium-Range Weather Forecasts, ERA5 Land reanalysis soil moisture dataset, showing a good agreement, mainly over mid-latitudes. The results indicate that there is added value to the results of the machine learning calibration, comparing to the uniform T-value. This work contributes to the exploitation of ESA CCI soil moisture data, while the produced data can support large scale soil moisture related studies.&lt;/p&gt;

Water balance changes in a crop sequence with lucerne

2001 ◽  
Vol 52 (2) ◽  
pp. 247 ◽  
Author(s):  
F. X. Dunin ◽  
C. J. Smith ◽  
S. J. Zegelin ◽  
R. Leuning
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Soil Depth ◽  
Water Storage ◽  
Growing Season ◽  
Soil Water Storage ◽  
Annual Rainfall ◽  
Root Extension ◽  
Annual Crops ◽  
Lower Productivity

In a detailed study of soil water storage and transport in a sequence of 1 year wheat and 4 years of lucerne, we evaluated drainage under the crop and lucerne as well as additional soil water uptake achieved by the subsequent lucerne phase. The study was performed at Wagga Wagga on a gradational clay soil between 1993 and 1998, during which there was both drought and high amounts of drainage (>10% of annual rainfall) from the rotation. Lucerne removed an additional 125 mm from soil water storage compared with wheat (root-zone of ~1 m), leading to an estimated reduction in drainage to 30–50% of that of rotations comprising solely annual crops and/or pasture. This additional soil water uptake by lucerne was achieved through apparent root extension of 2–2.5 m beyond that of annual crops. It was effective in generating a sink for soil water retention that was about double that of annual crops in this soil. Successful establishment of lucerne at 30 plants/m2 in the first growing season of the pasture phase was a requirement for this root extension. Seasonal water use by lucerne tended to be similar to that of crops in the growing season between May and September, because plant water uptake was confined to the top 1 m of soil. Uptake of water from the subsoil was intermittent over a 2-year period following its successful winter establishment. In each of 2 annual periods, uptake below 1 m soil depth began late in the growing season and terminated in the following autumn. Above-ground dry matter production of lucerne was lower than that by crops grown in the region despite an off-season growth component that was absent under fallow conditions following cropping. This apparent lower productivity of lucerne could be traced in part to greater allocation of assimilate to roots and also to late peak growth rates at high temperatures, which incurred a penalty in terms of lower transpiration efficiency. The shortfall in herbage production by lucerne was offset with the provision of timely, high quality fodder during summer and autumn. Lucerne conferred indirect benefits through nitrogen supply and weed control. Benefits and penalties to the agronomy and hydrology of phase farming systems with lucerne are discussed.

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.

What limits deep water uptake by deep-rooted crops?

2020 ◽  
Author(s):  
Camilla Rasmussen ◽  
Eva Rosenqvist ◽  
Fulai Liu ◽  
Dorte Bodin Dresbøll ◽  
Kristian Thorup-Kristensen ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Water Uptake ◽  
Deep Water ◽  
Large Scale ◽  
Root Zone ◽  
Root Length Density ◽  
Yield Losses ◽  
Deep Soil ◽  
Deep Roots ◽  
Water Limitations

&lt;p&gt;Minimizing water limitation during growth of agricultural crops is crucial to unlocking full yield potentials. Crop yield losses vary according to timing and severity of water limitations, but even short-term droughts can be a major cause of yield losses. While the potential influence of deep roots on water uptake has been highlighted numerous times, the actual contribution of deep roots to water uptake is yet to be revealed. The objective of this study is to get an understanding of what limits deep water uptake by deep-rooted crops under topsoil water limitations.&lt;/p&gt;&lt;p&gt;We found that deep-rooted crops experience water limitations despite access to water stored in the deep soil and we hypothesize that deep water uptake by deep-rooted crops is limited by 1) the hydraulic conductivity of the deeper part of the root zone, arising from limited root length density in combination with the hydraulic resistance of the roots or 2) by a hormonal response arising from the plant sensing dry conditions in the shallow soil leading to stomata closure, to conserve water. The two hypotheses can of course not be valid simultaneously, but both might be valid under certain conditions, at certain times or for certain species.&lt;/p&gt;&lt;p&gt;In a large-scale semi-field setup, we grow oil seed rape and by combining measures of root development, root hydraulic conductivity, transpiration, stomatal conductance, ABA concentrations and soil water content from a large scale semi-field setup with a mechanistic 3-D root-soil modelling approach (R-SWMS), we are able to us distinguish various scenarios and to evaluate what limits deep water uptake.&lt;/p&gt;

scholarly journals DRAINAGE OF AN IRRIGATED SALINE SOIL IN ALBERTA

1982 ◽  
Vol 62 (2) ◽  
pp. 387-396
Author(s):  
D. R. BENNETT ◽  
G. R. WEBSTER ◽  
B. A. PATERSON ◽  
D. B. HARKER
Keyword(s):  
Water Table ◽  
Crop Production ◽  
Saline Soil ◽  
Soil Depth ◽  
Drainage System ◽  
High Water ◽  
Coarse Sand ◽  
Irrigation Period ◽  
Dilution Effects ◽  
Sand And Gravel

A shallow subsurface drainage system effectively controlled a high water table and reduced salinity in an irrigated soil near Magrath, Alberta. Plastic corrugated tubing was installed in 1976 at depths of 1.1–1.5 m and spacings of 15 and 30 m in a moderately saline soil. During the irrigation period, the water table rose to within 0.3 m of the surface but was lowered to pre-irrigation levels within 48 h. The water table was maintained at, or below, the depth of the drains between irrigations. The 15- and 30-m spacings of the drain lines were equally effective in providing water table control in this lacustrine soil which was underlain by a coarse sand and gravel layer. Salinity levels were decreased substantially only within the surface 0.3-m soil depth. Quality of the drainage effluent remained constant throughout the growing season with only small dilution effects detected during irrigations. Barley yields increased to 3900 kg/ha in 1978, 2 yr following drainage of this saline soil which had been out of crop production for 20 yr.

scholarly journals Comparing the Deep Root Growth and Water Uptake of Intermediate Wheatgrass (Kernza®) to Alfalfa.

2021 ◽  
Author(s):  
Corentin Clement ◽  
Joost Sleiderink ◽  
Simon Fiil Svane ◽  
Abraham George Smith ◽  
Efstathios Diamantopoulos ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Water Uptake ◽  
Soil Depth ◽  
Deep Soil ◽  
Perennial Crops ◽  
Intermediate Wheatgrass ◽  
Deep Root ◽  
Grain Crop ◽  
Perennial Grain

Abstract AimsWater is the most important yield-limiting factor worldwide and drought is predicted to increase in the future. Perennial crops with more extensive and deep root systems could access deep stored water and build resilience to water shortage. In the context of human nutrition, perennial grain crops are very interesting. However, it is still questionable whether they are effective in using subsoil water. We compared intermediate wheatgrass (Kernza®) Thinopyrum intermedium, a perennial grain crop, to alfalfa Medicago sativa, a perennial forage, for subsoil root growth and water uptake.MethodsUsing TDR sensors, deuterium tracer labelling, minirhizotrons and the Hydrus-1D model we characterised the root distribution and water uptake patterns of these two perennial crops during two cropping seasons under field conditions down to 2.5 m soil depth.ResultsBoth crops grew roots down to 2.0 m depth that were active in water uptake but alfalfa was deeper rooted than intermediate wheatgrass. All experimental methods concluded that alfalfa used more water from below 1.0 m depth than intermediate wheatgrass. However, simulations predicted that intermediate wheatgrass used more than 20 mm of water after anthesis from below 1 m soil depth. Simulations confirmed the advantage of deep roots in accessing deep soil water under drought.ConclusionsIn regions with high groundwater recharge, growing deep-rooted perennial crops have great potential to exploit deep soil water that is often left unused. However, the road to a profitable perennial grain crop is still long and breeding intermediate wheatgrass (Kernza®) cultivars for increased root growth at depth seems to be a worthy investment for the development of more drought tolerant cultivars.

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