Regulated Deficit Irrigation as a Water-Saving Strategy for Onion Cultivation in Mediterranean Conditions

Field experiments were performed for two growing seasons in Spain under Mediterranean conditions to evaluate the response of onion growth, plant water status, bulb yield, irrigation water use efficiency (IWUE), and gross revenue to regulated deficit irrigation strategies (RDI). Seven irrigation treatments were utilized, including the application of 100% irrigation water requirements (IWR) during the entire growing season and the application of 75% or 50% of the IWR during one of the following growth stages: the vegetative growth, bulbing, and bulb ripening stages. The deficit irrigation strategies tested decreased marketable yields to greater or lesser extents; therefore, if water is readily available, full irrigation would be recommended. The RDI with 50% of the IWR during the bulb ripening stage led to important water savings (22%) and to slight decreases in yield (9%), improving IWUE (20%) compared with full irrigation, and this strategy can be recommended under a severe water shortage. A satisfactory bulb yield was obtained with RDI with 75% of the IWR during the bulb ripening stages, resulting in a lower reduction in yield (4%) and in an increased IWUE (9%); this strategy is an advisable strategy for onion production under a mild water shortage in Mediterranean conditions.

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Effect of Regulated Deficit Irrigation on Water Use and Economic Benefit of Processing Tomato (Solanum lycopersicum) in an Arid Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.4234 ◽

2014 ◽

Vol 926-930 ◽

pp. 4234-4237

Author(s):

Heng Jia Zhang ◽

Ai Cun Wen ◽

Ji Dong Zhang

Keyword(s):

Water Use ◽

Irrigation Water ◽

Deficit Irrigation ◽

Economic Benefit ◽

Arid Environment ◽

Full Irrigation ◽

Regulated Deficit Irrigation ◽

Water Deficits ◽

Processing Tomato ◽

Irrigated Crops

An experiment was conducted to determine the effect of regulated deficit irrigation (RDI) on water use and economic benefit of processing tomato in an arid environment. The results indicated that seasonal total irrigation water applied to processing tomato was significantly (p<0.05) saved by 14.3% to 42.9% under RDI compared to full irrigation. The irrigation water use efficiency (IWUE) of processing tomato was significantly improved with 32.4% and 57.2% in RDI plots respectively subjected to high and low water deficits at seedling as well as 26.1% in RDI plots subjected to low deficit at late fruiting compared with full irrigation, but no difference (p>0.05) occurred between fully irrigated crops and RDI plants subjected to water deficits at full fruiting as well as low deficit at late fruiting. However, in comparison with fully irrigated crops IWUE was significantly reduced with 20.5% and 22.2% in RDI plants both subjected to water deficits at flowering. Compared to full irrigation, the net income was significantly reduced with 11.3% to 45.3% in RDI plots except that subjected to low water deficit at seedling. Therefore, low water deficit RDI at seedling while full irrigation during flowering to late fruiting could be used to effectively reduce irrigation water application and improve IWUE of processing tomato without causing economic benefit reduction in arid areas.

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High Nitrogen Fertilization Modulates Morpho-Physiological Responses, Yield, and Water Productivity of Lowland Rice under Deficit Irrigation

Agronomy ◽

10.3390/agronomy11071291 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1291

Author(s):

Nasr M. Abdou ◽

Mohamed A. Abdel-Razek ◽

Shimaa A. Abd El-Mageed ◽

Wael M. Semida ◽

Ahmed A. A. Leilah ◽

...

Keyword(s):

Nitrogen Fertilizer ◽

Irrigation Water ◽

Nitrogen Fertilization ◽

Deficit Irrigation ◽

Physiological Responses ◽

Water Productivity ◽

Water Shortage ◽

Rice Production ◽

Lowland Rice ◽

Nitrogen Fertilizers

Sustainability of rice production under flooding conditions has been challenged by water shortage and food demand. Applying higher nitrogen fertilization could be a practical solution to alleviate the deleterious effects of water stress on lowland rice (Oryza sativa L.) in semi-arid conditions. For this purpose, field experiments were conducted during the summer of 2017 and 2018 seasons. These trials were conducted as split-split based on randomized complete blocks design with soil moisture regimes at three levels (120, 100 and 80% of crop evapotranspiration (ETc), nitrogen fertilizers at two levels (N1—165 and N2—200 kg N ha−1) and three lowland Egyptian rice varieties [V1 (Giza178), V2 (Giza177) and V3 (Sakha104)] using three replications. For all varieties, growth (plant height, tillers No, effective tillers no), water status ((relative water content RWC, and membrane stability index, MSI), physiological responses (chlorophyll fluorescence, Relative chlorophyll content (SPAD), and yield were significantly increased with higher addition of nitrogen fertilizer under all water regimes. Variety V1 produced the highest grain yield compared to other varieties and the increases were 38% and 15% compared with V2 and V3, respectively. Increasing nitrogen up to 200 kg N ha−1 (N2) resulted in an increase in grain and straw yields by 12.7 and 18.2%, respectively, compared with N1. The highest irrigation water productivity (IWP) was recorded under I2 (0.89 kg m−3) compared to (0.83 kg m−3) and (0.82 kg m−3) for I1 and I3, respectively. Therefore, the new applied agro-management practice (deficit irrigation and higher nitrogen fertilizer) effectively saved irrigation water input by 50–60% when compared with the traditional cultivation method (flooding system). Hence, the new proposed innovative method for rice cultivation could be a promising strategy for enhancing the sustainability of rice production under water shortage conditions.

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An Analytical View on Water Use Efficiency of Some Main Crops Grown in the Non-costal Parts of Thrace Region

Journal of Agriculture and Ecology Research International ◽

10.9734/jaeri/2020/v21i730156 ◽

2020 ◽

pp. 47-57

Author(s):

Recep Cakir

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Irrigation Water ◽

Field Experiments ◽

Soil Depth ◽

Growth Stages ◽

Irrigation Water Use ◽

Rainfed Farming ◽

Use Efficiency ◽

Thrace Region

The article contains data obtained from evaluations related to irrigation water use efficiency (IWUE) and water use efficiency (WUE), for the main crops, irrigated at different stages of growth, on the basis of some findings obtained in the Research Institute in Kırklareli. Each of the experimental crops was sown and farmed following procedures applied by the farmers in the region, except of the irrigation applications which were based on the sensitivity of a certain crop to water shortage in the soil, during the specific growth stages. Similar procedures were applied and all the experimental treatments were irrigated at growth stages, as predicted in the research methodology, and water amounts required to fill the 0-90 cm soil depth to field capacity were implied. Evaluation data obtained from the field experiments with three major crops, grown on the non-coastal lands of Thrace Region showed, that the productivity of irrigation water, as well as water use efficiencies of all analysed crops, are growth stage controlled. The highest IWUE and WUE efficiencies of 0.87 and 0.92 kg da-1 m-3; and 1.08 kg da-1 m-3 and 0.81 kg da-1 m-3; were determined for wheat and sunflower crops, irrigated at booting and flowering stages, respectively. Each m3 of irrigation water, applied during the most sensitive fruit formation stage (Ff) of pumpkin crop, provided additionally 8.47 kg da-1 fruit yield, 8.09 fruit numbers and 0.28 kg da-1 seed yields, more than those of rainfed farming (R).

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Yield and Water Use Efficiency of Potato under Alternate Furrows and Deficit Irrigation

International Journal of Agronomy ◽

10.1155/2020/8869098 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Kassu Tadesse Kassaye ◽

Wubengeda Admasu Yilma ◽

Mehiret Hone Fisha ◽

Dawit Habte Haile

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Irrigation Water ◽

Deficit Irrigation ◽

Field Experiments ◽

Potato Production ◽

Furrow Irrigation ◽

Total Biomass ◽

Use Efficiency ◽

Alternate Furrow Irrigation

The benefits of water-saving techniques such as alternate furrow and deficit irrigations need to be explored to ensure food security for the ever-increasing population within the context of declining availability of irrigation water. In this regard, field experiments were conducted for 2 consecutive dry seasons in the semiarid region of southwestern Ethiopia and investigated the influence of alternate furrow irrigation method with different irrigation levels on the yield, yield components, water use efficiency, and profitability of potato production. The experiment comprised of 3 irrigation methods: (i) conventional furrow irrigation (CFI), (ii) alternate furrow irrigation (AFI), and (iii) fixed furrow irrigation (FFI) combined factorially with 3 irrigation regimes: (i) 100%, (ii) 75%, and (iii) 50% of the potato water requirement (ETC). The experiment was laid out in randomized complete block design replicated thrice. Results revealed that seasonal irrigation water applied in alternate furrows was nearly half (170 mm) of the amount supplied in every furrow (331 mm). Despite the half reduction in the total amount of water, tuber (35.68 t ha−1) and total biomass (44.37 t ha−1) yields of potato in AFI did not significantly differ from CFI (34.84 and 45.35 t ha−1, respectively). Thus, AFI improved WUE by 49% compared to CFI. Irrigating potato using 75% of ETC produced tuber yield of 35.01 t ha−1, which was equivalent with 100% of ETC (35.18 t ha−1). Irrigating alternate furrows using 25% less ETC provided the highest net return of US$74.72 for every unit investment on labor for irrigating potato. In conclusion, irrigating alternate furrows using up to 25% less ETC saved water, provided comparable yield, and enhanced WUE and economic benefit. Therefore, farmers and experts are recommended to make change to AFI with 25% deficit irrigation in the study area and other regions with limited water for potato production to improve economic, environmental, and social performance of their irrigated systems.

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Impact of Deficit Irrigation on Shallow Saline Groundwater Contribution and Sunflower Productivity in the Imperial Valley, California

Water ◽

10.3390/w12020571 ◽

2020 ◽

Vol 12 (2) ◽

pp. 571

Author(s):

Mohamed Galal Eltarabily ◽

John M. Burke ◽

Khaled M. Bali

Keyword(s):

Irrigation Water ◽

Deficit Irrigation ◽

Growing Season ◽

Yield Reduction ◽

Growth Stages ◽

Crop Evapotranspiration ◽

Imperial Valley ◽

Saline Groundwater ◽

Irrigation Treatments ◽

Groundwater Contribution

Yield and production functions of sunflower (Helianthus annuus) were evaluated under full and deficit irrigation practices with the presence of shallow saline groundwater in a semi-arid region in the Imperial Valley of southern California, USA. A growing degree day (GDD) model was utilized to estimate the various growth stages and schedule irrigation events throughout the growing season. The crop was germinated and established using overhead irrigation prior to the use of a subsurface drip irrigation (SDI) system for the remainder of the growing season. Four irrigation treatments were implemented: full irrigation (100% full sunflower crop evapotranspiration, ETC), two reduced irrigation scenarios (95% ETC and 80% ETC), and a deficit irrigation scenario (65% ETC). The salinity of the irrigation water (EC) (Colorado River water) was nearly constant at 1.13 dS·m−1 during the growing season. The depth to groundwater and groundwater salinity (ECGW) were continuously monitored in five 3 m deep observation wells. Depth to groundwater fluctuated slightly under the full and reduced irrigation treatments, but drastically increased under deficit irrigation, particularly toward the end of the growing season. Estimates of ECGW ranged from 7.34 to 12.62 dS·m−1. The distribution of soil electrical conductivity (ECS) and soil matric potential were monitored within the active root zone (120 cm) at selected locations in each of the four treatments. By the end of the experiment, soil salinity (ECS) across soil depths ranged from 1.80 to 6.18 dS·m−1. The estimated groundwater contribution to crop evapotranspiration was 9.03 cm or approximately 16.3% of the ETC of the fully irrigated crop. The relative yields were 91.8%, 82.4%, and 83.5% for the reduced (95% and 80% ETC) and deficit (65% ETC) treatments, respectively, while the production function using applied irrigation water (IW) was: yield = 0.0188 × (IW)2 − 15.504 × IW + 4856.8. Yield reduction in response to water stress was attributed to a significant reduction in both seed weight and the number of seed produced resulting in overall average yields of 2048.9, 1879.9, 1688.1, and 1710.3 kg·ha−1 for the full, both reduced, and deficit treatments, respectively. The yield response factor, ky, was 0.63 with R2 = 0.745 and the irrigation water use efficiencies (IWUE) were 3.70, 3.57, 3.81, and 4.75 kg·ha−1·mm−1 for the full, reduced, and deficit treatments, respectively. Our results indicate that sunflowers can sustain the implemented 35% deficit irrigation with root water uptake from shallow groundwater in arid regions with a less than 20% reduction in yield.

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Luxury transpiration of winter wheat and its responses to deficit irrigation in North China Plain

Plant Soil and Environment ◽

10.17221/331/2018-pse ◽

2018 ◽

Vol 64 (No. 8) ◽

pp. 361-366 ◽

Cited By ~ 1

Author(s):

Liang Yueping ◽

Gao Yang ◽

Wang Guangshuai ◽

Si Zhuanyun ◽

Shen Xiaojun ◽

...

Keyword(s):

Winter Wheat ◽

Water Conservation ◽

Deficit Irrigation ◽

North China Plain ◽

North China ◽

Water Productivity ◽

Experimental Period ◽

Water Shortage ◽

Full Irrigation ◽

Daily Transpiration

Reducing crop luxury transpiration is an important step in improving water productivity; water shortage regions are potential hotspots for studying physiological water conservation. This study investigated the amount of luxury transpiration in winter wheat and its responses to different irrigation treatments in North China Plain. The results showed that luxury transpiration existed and increased with growth of winter wheat and after rainfall. In each sampling day, the amount of luxury transpiration under full irrigation was significantly higher than that under deficit irrigation. The average amount of luxury transpiration was 258.87 g/m<sup>2</sup> under full irrigation, and 125.18 g/m<sup>2</sup> under deficit irrigation during the experimental period. Although the amount of luxury transpiration was 2.09-fold higher under full irrigation than that in deficit irrigation, the water loss ratio due to luxury transpiration in deficit irrigation (8.13%) was significantly higher than that in full irrigation (6.75%). Furthermore, the ratio between luxury transpiration amount and crop daily transpiration was revealed in all sampling dates. Therefore, deficit irrigation should be generalized in the water shortage area, because it can save irrigation water and reduce the amount of luxury transpiration. Full irrigation should be carried out in the water abundant region mainly for higher production.

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Actual evapotranspiration and crop coefficients of irrigated lowland rice (Oryza sativa L.) under semiarid climate

Italian Journal of Agronomy ◽

10.4081/ija.2019.1059 ◽

2019 ◽

Vol 14 (1) ◽

pp. 19-25

Author(s):

Koffi Djaman ◽

Daran R. Rudnick ◽

Yonnelle D. Moukoumbi ◽

Abdoulaye Sow ◽

Suat Irmak

Keyword(s):

Irrigation Water ◽

Field Experiments ◽

Dry Season ◽

River Valley ◽

Rice Production ◽

Annual Rainfall ◽

Growth Stages ◽

Research Station ◽

Senegal River ◽

Crop Coefficients

Lowland irrigated rice is the predominant crop produced in the Senegal River Valley characterised by very low annual rainfall, high temperatures, and low relative humidity. The Senegal River is shared by Senegal, Mali, Mauritania, and Guinea, and serves as the main source of irrigation water for the adopted double rice cropping system. Developing appropriate resource management strategies might be the key factor for the sustainability of rice production in the region. This study aims to estimate rice seasonal evapotranspiration (ETa), irrigation water requirement, and to develop rice growth stage specific crop coefficients (Kc) to improve rice water productivity. Field experiments were conducted during the hot and dry seasons in 2014 and 2015 at the AfricaRice research station at Fanaye in Senegal. Irrigation water inputs were monitored and actual crop evapotranspiration was derived using the water balance method. Daily reference evapotranspiration (ETo) was estimated using the Penman-Monteith equation and the weather variables were collected at the site by an automated weather station. The results showed that the ETo during the hot and dry season from February 15th to June 30th varied from 4.5 to 9.9 mm and from 3.7 to 10.8 mm in 2014 and 2015, respectively, and averaged 6.8 mm d–1 in 2014 and 6.6 mm d–1 in 2015. The seasonal irrigation water amount for the transplanted rice was 1110 mm in 2014 and 1095 mm in 2015. Rice daily ETa varied from 4.7 to 10.5 mm in 2014 and from 4.4 to 10.5 mm in 2015 and averaged 8.17 mm in 2014 and 8.14 mm in 2015. Rice seasonal ETa was 841.5 mm in 2014 and 855.4 mm in 2015. The derived rice Kc values varied from 0.77 to 1.51 in 2014 and 0.85 to 1.50 in 2015. Rice Kc values averaged 1.01, 1.31, and 1.12 for the crop development, mid-season and late season growth stages, respectively. The Kc values developed in this study could be used for water management under rice production during the hot and dry season in the Senegal River Valley.

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SENSITIVITY OF CROP PLANTS TO WATER STRESS AT SPECIFIC DEVELOPMENTAL STAGES: REEVALUATION OF EXPERIMENTAL FINDINGS

Israel Journal of Plant Sciences ◽

10.1080/07929978.1995.10676596 ◽

1995 ◽

Vol 43 (2) ◽

pp. 99-111 ◽

Cited By ~ 17

Author(s):

Zvi Plaut

Keyword(s):

Water Stress ◽

Irrigation Water ◽

Field Experiments ◽

Developmental Stages ◽

Growth Period ◽

Soluble Solids ◽

Growth Stages ◽

Mild Stress ◽

Uniform Reduction ◽

Different Growth Stages

It has been suggested that in many crops differences in sensitivity to water stress occur at different growth stages. Since identical amounts of water may be applied, irrespective of whether a crop is exposed to relatively severe and short periods of stress or to extended periods of mild stress, the responses to such differing conditions should be compared. Unfortunately, such a comparison has not been conducted in most studies on sensitivity to water stress at different growth stages. In the present study, based on three field experiments conducted for different purposes, such a comparison was made for three crops: corn, sunflower, and tomato. In corn, distinct responses of ear and kernel yields to the timing of water stress were found. Withdrawal of irrigation water during flowering and cob formation resulted in greater yield losses than during other stages, indicating that this is a critical growth stage. However, slight and uniform reduction of water during the entire growth period resulted in significantly less damage to kernel or ear production, although the total amount of water applied was similar to that under staged withdrawal. In sunflowers, the withdrawal of irrigation water even at noncritical growth stages caused a more marked reduction in grain yield than did a uniform reduction throughout the entire season. In tomatoes, on the other hand, the withdrawal of irrigation water during specific growth stages caused minimal damage to fruit and total soluble solids yield as compared with fully irrigated control; reduction of irrigation water throughout the season brought about a significant decrease in yield. The difference between these crops is interpreted on the basis of the determinance of their floral meristems.

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Modelling Irrigation Water Requirements at Physiological Growth Stages of Okra Life Cycle Using CROPWAT Model for Derived Savannah and Humid Forest Zones of Nigeria

Agricultura tropica et subtropica ◽

10.1515/ats-2016-0003 ◽

2016 ◽

Vol 49 (1-4) ◽

pp. 20-29

Author(s):

OrevaOghene Aliku ◽

Suarau Odutola Oshunsanya

Keyword(s):

Life Cycle ◽

Irrigation Water ◽

Field Experiments ◽

Growth Stages ◽

Irrigation Water Requirement ◽

Flowering Stage ◽

Water Requirements ◽

Humid Forest ◽

Weather Parameters ◽

Accurate Quantification

Abstract Accurate quantification of irrigation water requirement at different physiological growth stages of okra (Abelmoschus esculentus L.) life cycle is important to prevent over or under irrigation. Field experiments were therefore initiated to model okra irrigation water requirements at the four physiological growth stages of okra life cycle using CROPWAT model. Derived savannah 1 (DS1), derived savannah 2 (DS2) and humid forest (HF) occupying 493.36 ha, 69.83 ha and 305.25 ha respectively were used. Some selected soil physical properties coupled with weather parameters were used to develop irrigation water requirements for okra crop. In DS1, the estimated crop co-efficient (Kc) values were 0.30, 0.52, 0.84 and 0.70 for the germination, crop growth, flowering and fruiting stages, respectively. Corresponding Kc values in DS2 were 0.30, 0.54, 0.90 and 0.84 and in the HF were 0.30, 0.56, 0.87 and 0.86 respectively. Daily crop evapo-transpiration values ranged from 1.16 to 3.36, 1.17 to 3.64, and 1.2 to 3.38 mm day-1 for DS1, DS2 and HF respectively with significant (p = 0.05) peak at the flowering stage for the three locations. Sustainable okra cultivation would require maximum daily irrigation water at flowering stage (reproductive phase) to meet the crop physiological needs and evapo-transpiration demand of the atmosphere.

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The effects of drought on the expression of TAO1, NCED and EIL1 genes and ABA content in tomato wild-type and flacca mutant

Archives of Biological Sciences ◽

10.2298/abs1201297m ◽

2012 ◽

Vol 64 (1) ◽

pp. 297-306 ◽

Cited By ~ 2

Author(s):

Ana Milosavljevic ◽

Ljiljana Prokic ◽

Milena Marjanovic ◽

Radmila Stikic ◽

Aneta Sabovljevic

Keyword(s):

Deficit Irrigation ◽

Treatment Duration ◽

Root Zone ◽

Full Irrigation ◽

Aba Signaling ◽

Wild Type ◽

Regulated Deficit Irrigation ◽

Similar Expression Pattern ◽

Effects Of Drought ◽

Aba Content

The effects of drought (partial root-zone drying-PRD and regulated deficit irrigation-RDI) and full irrigation (FI) on the expression of ABA biosynthetic genes (TAO1 and NCED), EIL1 gene and ABA content in the leaves of tomato wild-type (WT) and flacca mutant were investigated. Results confirmed differences in the expression of the investigated genes under the investigated treatments, during treatment duration as well as between investigated WT and flacca plants. The most significant differences between WT and flacca were found under PRD treatment. The similar expression pattern of all genes in the WT plants could indicate synergistic signaling pathways for ABA and ethylene. In flacca, reduced NCED and significant EIL1 expression might reflect the increase in ethylene production, which could influence the ABA signaling and production that occurred under PRD. Drought also induced an increase in ABA content that is most expressed in flacca under RDI.

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