Differences in soil water content between perennial and annual forages and crops grown under deficit irrigation and used by the dairy industry

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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Simulation of Canopy Cover, Soil Water Content and Yield Using FAO-AquaCrop Model under Deficit Irrigation Strategies

Russian Agricultural Sciences ◽

10.3103/s106836742003012x ◽

2020 ◽

Vol 46 (3) ◽

pp. 279-288

Author(s):

Mohmed A. M. Abdalhi ◽

Zhonghua Jia ◽

Wan Luo ◽

Osama O. Ali ◽

Cheng Chen

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Canopy Cover ◽

Cover Soil ◽

Aquacrop Model

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Estimating Soil Water Content and Evapotranspiration of Winter Wheat under Deficit Irrigation Based on SWAP Model

Sustainability ◽

10.3390/su12229451 ◽

2020 ◽

Vol 12 (22) ◽

pp. 9451

Author(s):

Xiaowen Wang ◽

Huanjie Cai ◽

Liang Li ◽

Xiaoyun Wang

Keyword(s):

Winter Wheat ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Irrigation Treatment ◽

Water Dynamics ◽

Growth Stages ◽

Irrigation Amount ◽

Swap Model

Deficit irrigation strategy is essential for sustainable agricultural development in arid regions. A two−year deficit irrigation field experiment was conducted to study the water dynamics of winter wheat under deficit irrigation in Guanzhong Plain in Northwest China. Three irrigation levels were implemented during four growth stages of winter wheat: 100%, 80% and 60% of actual evapotranspiration (ET) measured by the lysimeter with sufficient irrigation treatment (CK). The agro−hydrological model soil−water−atmosphere−plant (SWAP) was used to simulate the components of the farmland water budget. Sensitivity analysis for parameters of SWAP indicated that the saturated water content and water content shape factor n were more sensitive than the other parameters. The verification results showed that the SWAP model accurately simulated soil water content (average relative error (MRE) < 21.66%, root mean square error (RMSE) < 0.07 cm3 cm−3) and ET (R2 = 0.975, p < 0.01). Irrigation had an important impact on actual plant transpiration, but the actual soil evaporation had little change among different treatments. The average deep percolation was 14.54 mm and positively correlated with the total irrigation amount. The model established using path analysis and regression methods for estimating ET performed well (R2 = 0.727, p < 0.01). This study provided effective guidance for SWAP model parameter calibration and a convenient way to accurately estimate ET with fewer variables.

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Water Use, Growth, and Fruit Yield of `Hosui' Asian Pears under Deficit Irrigation

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.119.3.383 ◽

1994 ◽

Vol 119 (3) ◽

pp. 383-388 ◽

Cited By ~ 46

Author(s):

Horst W. Caspari ◽

M. Hossein Behboudian ◽

David J. Chalmers

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Use ◽

Deficit Irrigation ◽

Fruit Size ◽

Fruit Growth ◽

Volume Measurements ◽

Pyrus Serotina ◽

Return Bloom

Five-year old `Hosui' Asian pear (Pyrus serotina Rehder) trees growing in drainage lysimeters and trained onto a Tatura trellis were subjected to three different irrigation regimes. Weekly water use (WU) was calculated using the mass-balance approach. Soil-water content of control lysimeters was kept at pot capacity, while deficit irrigation was applied before [regulated deficit irrigation (RDI)] and during the period of rapid fruit growth [late deficit irrigation (LDI)]. Soil-water content was maintained at ≈50% and 75% of pot capacity for RDI and LDI, respectively. Deficit irrigation reduced mean WU during RDI and LDI by 20%. The reduced WU was caused by lower stomatal conductance (gs) on deficit-irrigated trees. RDI trees had more-negative diurnal leaf water potentials (ψl). The ψl, gs, and WU remained lower for 2 weeks after RDI was discontinued. RDI reduced shoot extension and summer pruning weights, whereas winter pruning weights were not different between treatments. Except for the final week of RDI, fruit growth was not reduced, and fruit from RDI grew faster than the control during the first week after RDI. In contrast, fruit volume measurements showed that fruit growth was clearly inhibited by LDI. Final fruit size and yield, however, were not different between treatments. Return bloom was reduced by RDI but was not affected by LDI.

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Tall Fescue Rooting as Affected by Deficit Irrigation

HortScience ◽

10.21273/hortsci.42.3.688 ◽

2007 ◽

Vol 42 (3) ◽

pp. 688-691 ◽

Cited By ~ 8

Author(s):

Jinmin Fu ◽

Jack Fry ◽

Bingru Huang

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Tall Fescue ◽

Water Conservation ◽

Deficit Irrigation ◽

Imaging System ◽

Conservation Strategy ◽

Growth Enhancement ◽

Root Characteristics

Deficit irrigation is increasingly used to conserve water, but its impact on turfgrass rooting has not been well documented. The objective of this study was to examine the effects of deficit irrigation on ‘Falcon II’ tall fescue (Festuca arundinacea Schreb.) root characteristics in the field using a minirhizotron imaging system. The experiment was conducted on a silt loam soil from the first week of June to mid-Sept. 2001 and 2002 using a mobile rainout shelter under which turf received applications of 20%, 60%, or 100% of actual evapotranspiration (ET) twice weekly. Neither soil water content (0 to 25 cm) nor tall fescue rooting between 4.1- and 50.1-cm depths was affected by irrigation at 60% compared with 100% ET. Despite consistently lower soil water content, tall fescue irrigated at 20% ET exhibited an increase in root parameters beginning in July or August. Tall fescue subjected to 20% ET irrigation had greater total root length and surface area on two of five monitoring dates in 2002 compared with that receiving 100% ET. Evaluation of tall fescue rooting by depth indicated that root proliferation at 20% ET was occurring between 8.7- and 36.3-cm depths. As evaluated under the conditions of this experiment, turfgrass managers using deficit irrigation as a water conservation strategy on tall fescue should not be concerned about a reduction in rooting deep in the soil profile, and irrigation at 20% ET may result in root growth enhancement.

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Soil moisture heterogeneity during deficit irrigation alters root-to-shoot signalling of abscisic acid

Functional Plant Biology ◽

10.1071/fp07009 ◽

2007 ◽

Vol 34 (5) ◽

pp. 439 ◽

Cited By ~ 60

Author(s):

Ian C. Dodd

Keyword(s):

Water Content ◽

Root System ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Plant Root ◽

Arithmetic Mean ◽

Similar Amount ◽

Graft Union ◽

Plant Root System

The effects of different irrigation techniques on leaf xylem ABA concentration ([X-ABA]leaf) were compared in tomato (Lycopersicon esculentum Mill.). During partial rootzone drying (PRD), water was distributed unevenly to the root system such that part was irrigated while the remainder was allowed to dry the soil. During conventional deficit irrigation (DI), plants received the same volume of water as PRD plants, but water was distributed evenly to the entire root system. When the plant root system was allowed to explore two separate soil compartments, DI plants had a higher [X-ABA]leaf than PRD plants with moderate soil drying, but PRD plants had a higher [X-ABA]leaf than DI plants as the soil dried further. The difference in [X-ABA]leaf between the two sets of plants was not because of differences in either whole pot soil water content (θpot) or leaf water potential (Ψleaf). To investigate the contribution of different parts of the root system to [X-ABA]leaf, individual shoots were grafted onto the root systems of two plants grown in two separate pots, so that the graft union had the appearance of an inverted ‘Y’. After sap collection from detached leaves, removal of the shoot below the graft union allowed sap collection from each root system. Again, DI plants had a higher [X-ABA]leaf than PRD plants when the soil was relatively wet, but the opposite occurred as the soil dried. Root xylem ABA concentration ([X-ABA]root) increased exponentially as soil water content (θ) declined. In DI plants, [X-ABA]root from either pot (or the arithmetic mean of [X-ABA]root) accounted for a similar amount of the variation in [X-ABA]leaf. In PRD plants, [X-ABA]root from the watered side underestimated [X-ABA]leaf, whereas [X-ABA]root from the dry side overestimated [X-ABA]leaf. The arithmetic mean of [X-ABA]root best explained the variation in [X-ABA]leaf, implying continued sap flow from the dry part of the root system (Jdry) at soil water potentials (Ψsoil) at which Jdry had ceased in previous studies of PRD plants (Yao et al. 2001). Evaluating the relationship between Jdry and Ψsoil may assist in maintaining export of ABA (and other growth regulators) from the drying part of the root system, to achieve desirable horticultural outcomes during PRD.

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Sensitivity of Continuous and Discrete Plant and Soil Water Status Monitoring in Peach Trees Subjected to Deficit Irrigation

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.124.4.437 ◽

1999 ◽

Vol 124 (4) ◽

pp. 437-444 ◽

Cited By ~ 107

Author(s):

David A. Goldhamer ◽

Elias Fereres ◽

Merce Mata ◽

Joan Girona ◽

Moshe Cohen

Keyword(s):

Water Potential ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Root Zone ◽

Water Status ◽

Full Irrigation ◽

Trunk Diameter ◽

Peach Trees

To characterize tree responses to water deficits in shallow and deep rooted conditions, parameters developed using daily oscillations from continuously measured soil water content and trunk diameter were compared with traditional discrete monitoring of soil and plant water status in lysimeter and field-grown peach trees [Prunus persica (L.) Batsch `O'Henry']. Evaluation occurred during the imposition of deficit irrigation for 21 days followed by full irrigation for 17 days. The maximum daily available soil water content fluctuations (MXAWCF) taken at any of the four monitored root zone depths responded most rapidly to the deficit irrigation. The depth of the MXAWCF increased with time during the deficit irrigation. Differences relative to a fully irrigated control were greater in the lysimeter than the field-grown trees. Minimum daily trunk diameter (MNTD) and maximum daily trunk shrinkage (MDS) responded sooner than midday stem water potential (stem Ψ), predawn or midday leaf water potential (predawn leaf Ψ and leaf Ψ), or photosynthesis (A). Parameters based on trunk diameter monitoring, including maximum daily trunk diameter (MXTD), correlated well with established physiological parameters of tree water status. Statistical analysis of the differences in the measured parameters relative to fully irrigated trees during the first 10 days of deficit irrigation ranked the sensitivity of the parameters in the lysimeter as MXAWCF > MNTD > MDS > MXTD > stem Ψ = A = predawn leaf Ψ = leaf Ψ. Equivalent analysis with the field-grown trees ranked the sensitivity of the parameters as MXAWCF > MNTD > MDS > stem Ψ = leaf Ψ = MXTD = predawn leaf Ψ > A. Following a return to full irrigation in the lysimeter, MDS and all the discrete measurements except A quickly returned to predeficit irrigation levels. Tree recovery in the field-grown trees was slower and incomplete due to inadequate filling of the root zone. Fruit size was significantly reduced in the lysimeter while being minimally affected in the field-grown trees. Parameters only available from continuous monitoring hold promise for improving the precision of irrigation decision-making over the use of discrete measurements.

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Patterns of Soil and Tree Water Status and Leaf Functioning during Regulated Deficit Irrigation Scheduling in Peach

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.5.580 ◽

1993 ◽

Vol 118 (5) ◽

pp. 580-586 ◽

Cited By ~ 51

Author(s):

J. Girona ◽

M. Mata ◽

D.A. Goldhamer ◽

R.S. Johnson ◽

T.M. DeJong

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deficit Irrigation ◽

Prunus Persica ◽

Irrigation Treatment ◽

Irrigation Scheduling ◽

Water Infiltration ◽

Control Treatment ◽

Regulated Deficit Irrigation

Seasonal patterns of soil water content and diurnal leaf water potential (LWP), stomatal conductance(gs), and net CO2 assimilation (A) were determined in a high-density peach [Prunus persica(L) Batsch cv. Cal Red] subjected to regulated deficit irrigation scheduling. The regulated deficit irrigation treatment caused clear differences in soil water content and predawn LWP relative to control irrigation treatments. Treatment differences in midday LWP, gs, and A were also significant, but not as distinct as differences in predawn LWP. Leaves on trees subject of the deficit irrigation treatment were photosynthetically more water-use-efficient during the latter part of the stress period than were the nonstressed trees. Midday LWP and gs, on trees that received the regulated deficit irrigation treatment did not recover to control treatment values until more than 3 weeks after full irrigation was resumed at the beginning of state III of fruit growth, because of water infiltration problems in the dry soil caused by the deficit irrigation. The regulated deficit irrigation treatment caused only a 8% reduction in trunk growth relative to the control, but resulted in a 40% savings in irrigation requirements.

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