Optimal Water Supply Research Articles

Designing a high-yielding maize ideotype for a changing climate in Lombardy plain (northern Italy)

The expected climate change will affect the maize yields in view of air temperature increase and scarce water availability. The application of biophysical models offers the chance to design a drought-resistant ideotype and to assist plant breeders and agronomists in the assessment of its suitability in future scenarios. The aim of the present work was to perform a model-based estimation of the yields of two hybrids, current vs ideotype, under future climate scenarios (2030–2060 and 2070–2100) in Lombardy (northern Italy), testing two options of irrigation (small amount at fixed dates vs optimal water supply), nitrogen (N) fertilization (300 vs 400kgNha−1), and crop cycle durations (current vs extended). For the designing of the ideotype we set several parameters of the ARMOSA process-based crop model: the root elongation rate and maximum depth, stomatal resistance, four stage-specific crop coefficients for the actual transpiration estimation, and drought tolerance factor.The work findings indicated that the current hybrid ensures good production only with high irrigation amount (245–565mmy−1). With respect to the current hybrid, the ideotype will require less irrigation water (−13%, p<0.01) and it resulted in significantly higher yield under water stress condition (+15%, p<0.01) and optimal water supply (+2%, p<0.05). The elongated cycle has a positive effect on yield under any combination of options. Moreover, higher yields projected for the ideotype implicate more crop residues to be incorporated into the soil, which are positively correlated with the SOC sequestration and negatively with N leaching. The crop N uptake is expected to be adequate in view of higher rate of soil mineralization; the N fertilization rate of 400kgNha−1 will involve significant increasing of grain yield, and it is expected to involve a higher rate of SOC sequestration.

Climate change and Mediterranean agriculture: Impacts on winter wheat and tomato crop evapotranspiration, irrigation requirements and yield

High resolution climate data, derived from the ENSEMBLES Regional Climate Models outputs, were used to assess the impacts of climate change on crop water and irrigation requirements and yield of winter wheat and tomato in the Mediterranean region. Data, based on the A1B emission scenario, were arranged purposefully to represent the years 2000 and 2050. Over this 50-years span, an overall reduction of annual precipitation of 39.1±55.1mm and an increase of air temperature of 1.57±0.27°C (from 0.84 to 2.31°C) are predicted. The consequent increase of annual reference evapotranspiration is 92.3±42.1mm (6.7%). The potentially cultivable areas of winter wheat and tomato may increase by 7 and 24%, respectively, and might be extended prevalently in the Northern Mediterranean countries. The average length of growing season was estimated to be shorter in 2050 by 15 and 12 days for wheat and tomato, respectively. Due to anticipation and shortening of growing season, the crop evapotranspiration is foreseen to be reduced by 6 and 5% for wheat and tomato, respectively. The net irrigation requirements (NIR) under optimal water supply may decrease by 11% for wheat and 5% for tomato. Under moderate deficit irrigation, NIR are foreseen to decrease by 14 and 7% respectively for wheat and tomato. As a whole, a slight increase of relative yield losses (RYL) is expected for rainfed wheat, particularly in the Northern Mediterranean. Overall, tomato RYL are not expected to change in the future. The foreseen impact of precipitation decrease is more relevant for winter-spring crops. Hence, the adoption of supplemental irrigation for winter wheat could become more widespread also in the northern Mediterranean countries. Differently, for tomato, cropped in most areas out of the rainy season, the irrigation strategies are expected to remain similar as today.

Épilation difficile et épilation à problème

The expected climate change will affect the maize yields in view of air temperature increase and scarce water availability. The application of biophysical models offers the chance to design a drought-resistant ideotype and to assist plant breeders and agronomists in the assessment of its suitability in future scenarios. The aim of the present work was to perform a model-based estimation of the yields of two hybrids, current vs ideotype, under future climate scenarios (2030–2060 and 2070–2100) in Lombardy (northern Italy), testing two options of irrigation (small amount at fixed dates vs optimal water supply), nitrogen (N) fertilization (300 vs 400 kg N ha− 1), and crop cycle durations (current vs extended). For the designing of the ideotype we set several parameters of the ARMOSA process-based crop model: the root elongation rate and maximum depth, stomatal resistance, four stage-specific crop coefficients for the actual transpiration estimation, and drought tolerance factor.The work findings indicated that the current hybrid ensures good production only with high irrigation amount (245–565 mm y− 1). With respect to the current hybrid, the ideotype will require less irrigation water (− 13%, p < 0.01) and it resulted in significantly higher yield under water stress condition (+ 15%, p < 0.01) and optimal water supply (+ 2%, p < 0.05). The elongated cycle has a positive effect on yield under any combination of options. Moreover, higher yields projected for the ideotype implicate more crop residues to be incorporated into the soil, which are positively correlated with the SOC sequestration and negatively with N leaching. The crop N uptake is expected to be adequate in view of higher rate of soil mineralization; the N fertilization rate of 400 kg N ha− 1 will involve significant increasing of grain yield, and it is expected to involve a higher rate of SOC sequestration.

Comparison of methods for estimating reference evapotranspiration in two locations of Espirito Santo

The determination or estimate of reference evapotranspiration (ETo) is of great importance to determine the optimal supply of water to a culture. The Penman-Monteith (FAO 56) is recommended as the standard for estimating ETo, when the absence of weighing lysimeter. In the present study it was compared five methods for estimating the ETo, with the Penman-Monteith method in the dry and humid season of the year 2012, in two localities of the state of Espirito Santo, in the north (Nova Venecia) and the mountainous region (Santa Teresa). To assess the adjustment of the methods for estimating the ETo with the Penman-Monteith (FAO-56) it was used the values of the coefficients of determination (R 2 ) and correlation (r), the Standard Error of Estimate (SEE), Standard Error of Estimate Adjusted (SEEa), Standard Error of Estimate Adjusted by Origin (SEEao) for methods that showed better assessment, and the agreement indexes (d) and performance (c). The methods Priestley-Taylor, Hargreaves &amp; Samani and Blaney &amp; Criddle, showed better assessment when compared with the Penman-Monteith method to Santa Teresa-ES, for the two seasons studied, the first two overestimated and the Blaney &amp; Criddle underestimated the ETo values. The methods of Camargo and Makkink, obtained lower classification of estimate of ETo. To Nova Venecia-ES in the rainy season the methods Priestley-Taylor, Hargreaves &amp; Samani and Blaney &amp; Criddle, obtained the best results, but the first two overestimated and the last underestimated, for the dry season only the methods Priestley-Taylor, Hargreaves &amp; Samani showed better assessment, overestimating the values of ETo. In both seasons the methods of Camargo and Makkink obtained lower classification, as well Blaney &amp; Criddle for the dry season. Hargreaves &amp; Samani and Priestley-Taylor are indicated for both locations, and Blaney &amp; Criddle, except in the dry season of Nova Venecia-ES.

Optimizing the dammed: Water supply losses and fish habitat gains from dam removal in California

Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate removing rim dams in California's Central Valley to highlight promising habitat and unpromising economic use tradeoffs for water supply and hydropower. CALVIN, an economic-engineering optimization model, is used to evaluate water storage and scarcity from removing dams. A warm and dry climate model for a 30-year period centered at 2085, and a population growth scenario for year 2050 water demands represent future conditions. Tradeoffs between hydropower generation and water scarcity to urban, agricultural, and instream flow requirements were compared with additional river kilometers of habitat accessible to anadromous fish species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Removing individual dams decreases statewide delivered water by 0–2282 million cubic meters and provides access to 0 to 3200 km of salmonid habitat upstream of dams. The method described here can help prioritize dam removal, although more detailed, project-specific studies also are needed. Similarly, improving environmental protection can come at substantially lower economic cost, when evaluated and operated as a system.

Design of dual column water purification system for industrial gamma irradiator based of PUROLITE® resins

When gamma irradiators are not in use, they have to be stored in nuclear grade water pool. This water serves as shielding and the medium for the removal of generated heat. To prevent corrosion damage to the gamma source and other equipment a purification system controls the water quality. Also, this system serves as the make-up water system for supplies and maintains the de-ionized water level in the gamma source storage pool. In this paper, the design of the dual system for purification and make-up water for optimal water supply and its chemical parameters in the gamma source storage pool is presented. For this purpose, the characteristics of activated carbon purifier, anionic and cationic demineralizers have been determined. “Aerb Safety Standard”, “Purolite Ion Exchange Design Code” and “Canadian Water Refining Company Manual” have been used to design IR-136 gamma irradiator storage pool purification and make-up water system. The main objective of the design is to maintain water purity throughout the storage time.

The Altered Output of Aloe vera (L.) Burm. f. Crop under Differential Water Stress Conditions

Experiments were conducted the xerophytic Aloe vera (L.) Burm. f . plant samples of three age group viz . 20 days, 40 days and 60 days old plants in order to estimate the change in productivity (total yield) and protein content under differential water stress conditions. The plantlets were subjected to different water stress conditions under excess, optimum and deficient water supply under water-logging, daily-watering, alternate-day, bi-weekly, once-a-week water supply conditions. It was found that the total productivity and protein content was maximum in once-a-week watered plants and minimum in daily-watered plants indicating that the cultivation practice adopted for best production of the crop should be based on intermittent weekly rather than continuous water supply to the plants. Water-logged conditions were detrimental for their survival.

Optimal Water Supply System Management by Leakage Reduction and Energy Recovery

Abstract In WDS characterized by significant variation in elevation, the necessity of pumping water to higher levels is conflicted by a requirement to reduce excess pressure. A multi-objective optimization methodology is presented to minimize leakage and to minimize the difference between operational pumping costs and income generated through energy recovery by strategically locating in the network Pumps operating As Turbines (PATs), which can act in an analogous fashion to conventional PRVs. The approach is demonstrated on a case study resulting in a clear economic benefit from installing PATs for energy recovery in conjunction with a combined pump-scheduling and pressure management regime.

Effect of irrigation on yield parameters and antioxidant profiles of processing cherry tomato

AbstractA two-year (2010 and 2011) open field experiment was conducted to study the effect of drip irrigation and seasonal variation on the yield parameters and main bioactive components, carotenoids (mainly all trans, cis lycopene, and β-carotene), polyphenols (chlorogenic acid, caffeic acid, gallic acid, quercetin, rutin, naringin, etc.), and tocopherols of processing Strombolino F1 cherry tomatoes. The irrigated plants (STI) gave a higher marketable yield (61% and 101% respectively), and rain fed plants showed a yield loss. Water supply had a strong positive (R2=0.98) effect on marketable yield in 2011, but weak (R2=0.69) in 2010. In both years, the antioxidant concentration (all carotenoids, total polyphenols, tocopherols) showed a decrease with irrigation. Water supply affected the composition of carotenoids to a considerable extent. The optimum water supply treatment gave a lower proportion of lycopene than the rain fed control (STC) treatment. We observed significant negative correlation between rutin concentration and irrigation. The α-tocopherol concentration was significantly higher in STC treatments. Irrigation negatively influenced antioxidant concentrations of cherry tomato fruits, but higher yield could account for the concentration loss of individual fruits by higher antioxidant production per unit area.

Research on minimizing electric power usage in water distribution system

The purpose of this study is to propose the optimal water supply control and management plan for minimizing power usage by water distribution pumps. The key topic of this study is to determine from which treatment plants water should be supplied, and through which supply stations it should be distributed. This study devised an optimal model of the ‘route/flow decision problem’ for minimizing power use in the water distribution system while meeting demand in the distributing areas, and formulated the model by means of mixed integer linear programming (MILP). Then to validate the MILP model we attempted a case study in an actual water distribution system. The research demonstrated the effectiveness of the proposed optimization when applied to minimizing power usage in water operation.

Effect of drought stress and Glomus inoculation on selected physiological processes of sweet pepper (Capsicum annuum L. cv. 'Slávy')

Sweet pepper (Capsicum annuumL. ‘Slávy‘ F1) plants were colonized by the vesicular-arbuscular mycorrhizal fungusGlomusand grown in two irrigational levels: 1. optimal water supply (the irrigation activation by available water capacity (AWC) &lt; 65 %); 2. drought stress (irrigation activation by AWC &lt; 45 %). In the field experiment selected physiological parameters, such as photosynthetic rate, transpiration rate, stomatal conductance and water use efficiency were observed. The highest photosynthetic activity was observed in the first measuring date in both experimental years (2010: 7.5–8.1 μmol . m−2. s−12011: 6.1–8.6 μmol . m−2. s−1). In the next measuring dates, when the temperature decreased and the plants were older stage, the activity of leaves decreased. The inoculation byGlomusspecies had not clear effect. The inoculation did not increased the activity of plants (photosynthesis, transpiration) under optimal water supply conditions. However, based on results from 2011, under drought stress the inoculation had slightly positive effect on the photosynthetic rate. Under drought stress conditions, the water use efficiency (WUE) of plants increased slightly by theGlomusinoculation (from 4.7 to 5.1 μmol CO2. mmol H2O−1).

Conservation tillage and optimal water supply enhance microbial enzyme (glucosidase, urease and phosphatase) activities in fields under wheat cultivation during various nitrogen management practices

Field experiments were conducted on sandy clay loam soil at New Delhi, during the winter season of 2007 and 2008 to investigate the effect of tillage, irrigation regimes, i.e. sub-optimal, optimal and supra-optimal water supply, and integrated nutrient management practices (INM) on soil enzymatic activities after cultivation of wheat (Triticum aestivum). Soil glucosidase (54.5%), urease (88.8%), acid phosphatase (97.4%) and alkaline phosphatase (85.3%) activities increased significantly under conservation tillage compared with conventional tillage fields. An optimal water supply (i.e. three irrigations) led to a significant increase in soil enzymatic activity over sub-optimal (i.e. two) and supra-optimal (five) irrigation. Urease activity was slightly lower in the sub-optimal irrigations, but higher in supra-optimal irrigations by 15.5% than in optimal irrigation in conventional tillage. This study suggests that inorganic and organic nutrient combinations with conservation tillage and optimal water supply significantly improved soil enzymatic activities.

Long term researches regarding the irrigation influence on sugarbeet crop inthe Crisurilor Plain

The paper is based on the researches carried out in the long term trial placed on the preluvosoil from Agricultural Research and Development Station Oradea, Crisurilor Plain in during 1976–2012.&#x0D; The soil water reserve in 0–75 cm depth decreased bellow easily available water content every year and in 32% of years the soil water reserve decreased bellow wilting point. For optimum water supply an irrigation rate of 2665 m3 ha-1 (variation interval 500–5090 m3 ha-1) was needed.&#x0D; The irrigation determined improving of water/temperature + light report (Domuta climate index) with 47.4% in average in the period May–September. A statistically very significant connection was quantified between this indicator and the yield.&#x0D; Daily water consumption increased in the irrigated variant, the biggest difference in comparison with unirrigated variant was registered in August, 86% in comparison with unirrigated variant. As consequence, the value of the total water consumption increased with 50%, variation interval was 11–154%. The irrigation covered 37.8% of total water consumption, the variation interval was 8.3%–67.9%.&#x0D; The yield level of the sugarbeet increased in average with 61%, the variation interval was 9–227%. Standard deviation was lower in the irrigated variant and this emphasizes an improve of the yield stability with 25.1%. The sugar content of the sugarbeet roots from irrigated variant increased statistically very significantly in the droughty years and differs significantly in the rainy years.&#x0D; Water use efficiency increased in the irrigated variant with 7% and irrigation water use efficiency was between 7.9 kg yield gain 1 m-3 irrigation water and 17.4 kg yield gain 1 m-3 irrigation water.&#x0D; The positive influence of the irrigation on microclimate, water consumption, yield level, stability and quality and on water use efficiency sustain the need of the irrigation in sugarbeet from Crisurilor Plain.

Effect of drought stress and mycorrhizal inoculation on the growth, photosynthetic activity and water use efficiency of leek (Allium porrum L. 'Gigante Suizo')

During the experiments it was examined two irrigation levels: 1. optimal water supply – the irrigation activation by available water capacity (AWC) &lt; 65 %; 2. drought stress – irrigation activation by AWC &lt; 45 %) and inoculation of plants by the vesicular-arbuscular mycorrhizal fungusGlomusin leek culture. The effect of treatments on the photosynthetic rate (A), transpiration rate (E), water use efficiency (WUE), biomass production (weight, dry matter content of different plant part), size of pseudostem, leaf area and specific leaf area (SLA) was observed. The drought stress had effect on all observed parameters: it decreased the photosynthetic and transpiration rate (A: from 5.04–5.37 to 3.33–3.43 µmol CO2.m−2. s−1, E: from 1.78–1.91 to 0.99–1.03 mmol H2O. m−2. s−1in the average of 5 measuring date), the weight total fresh weight of plants: from 355–453 g to 152–255 g), and the leaf area, the length and diameter of pseudostem, too. The WUE, the dry matter content and the thickness of leaves increased under stress. In the most parameters, the water supply had stronger effect than the inoculation. The inoculation had positive effect mainly under drought stress: it improved the WUE at 3 measuring time (from 3.45 to 3.50 μmol CO2.mmol H2O−1, in the average of 5 measuring date), increased the weight (total fresh weight of plants: from 152 g to 255 g) and the leaf area (from 0.16 to 0.12 m2).

Field partition by proximal and remote sensing data fusion

There is a growing interest in the application of remote and proximal sensing technologies to precision agriculture for the estimation of soil and crop variability. The objective of this research was to jointly analyse data from proximal and remote sensors through geostatistics and a non-parametric clustering approach to delineate homogenous zones. The study was carried out on tomato crop in an experimental field in southern Italy. The field was split into two blocks in order to differentiate the two irrigation treatments: Optimal water supply conditions (OP), Deficit irrigation conditions. The collected multi-sensor data were: 1) bulk electrical conductivity from electromagnetic induction (EMI) sensor, 2) vegetation indices (normalised difference vegetation index, RNIR/RGreen index and normalised difference red edge) calculated from two remote sensing images of WorldView-2 satellite; 3) radiance data from one GeoEye satellite image. Multivariate geostatistics and a clustering approach were applied to the overall multi-sensor dataset reported in the above points 1 and 2, whereas the data of the point 3 were clustered to validate the field delineation. The approach allowed us to integrate the data of the different sensors and to identify three homogenous sub-field areas related to the intrinsic properties of soil and the crop response. The comparison between the previous delineation and the one obtained with GeoEye data, after water treatment differentiation, showed that the plant response was more affected by water management than soil properties. The approach has the potential to define prescription maps in precision agriculture.

A large-scale conjunctive management model of water resources for an arid irrigation district in China

The quantity of available water resources has been recognized as the key limiting factor for development of most of the arid regions. This paper focuses on the simulation–optimization for conjunctive use of surface water and groundwater on a large scale. In this study, Hetao Irrigation District in China, one of the largest irrigation districts in the Yellow River basin, is selected as a representative study area. The conjunctive management model of water resources is developed by means of dynamically coupling a large-scale hydrological model with an optimal allocation model. A groundwater level is adopted in the coupled model as the constraint condition and the optimal conjunctive utilization quantity of surface water and groundwater is set as the objective function. Finally, the coupled model is applied to calculate the optimal water supply quantity of surface water and groundwater and sustainable utilization scheme of water resources for 2020 and 2030 in Hetao Irrigation District. The modeling results demonstrate the conjunctive management model of water resources is an effective tool for appraising water resources in large-scale arid regions.

Optimized operation of water distribution system using multipurpose fuzzy LP model

This research is aimed at multiple-objective optimization of water operations in a water supply and distribution system. These objectives include reducing energy use while at the same time meeting water quality needs. The first objective is to propose water operations aimed at minimizing energy consumption. The second is to optimize water supply and distribution from the standpoint of water quality based on total organic carbon and the third is to attempt optimization that satisfies the first two objectives through multipurpose fuzzy linear programming (LP). This study mathematically formulates water operation planning issues focusing on reducing energy consumption and improving water quality in a water distribution system. Estimates show that a reduction in energy use of around 10% can be expected. Fuzzy LP is applied to achieve a balance among multiple objectives. The research demonstrates the effectiveness of the proposed multipurpose optimization when applied to trade-offs in water operation.

Nitrogen accumulation in lucerne (Medicago sativa L.) under water deficit stress

In order to study nitrogen accumulation in aboveground and root dry mass in lucerne (Medicago sativa L.) under water deficit stress, a pot experiment was carried out at the Institute of Forage Crops, Pleven, Bulgaria. The plants were grown under optimum water supply (75-80% FC) and 10-days water deficit stress was simulated at the stage of budding by interrupting the irrigation until soil moisture was reduced to 37-40% FC. Mineral nitrogen fertilization (ammonium nitrate) at the doses of 40, 80, 120 and 160 mg N kg-1 soil was applied. It was found that nitrogen accumulation in dry aboveground mass was reduced to 18.0%, and in dry root mass to 26.5% under water deficit stress. Mineral nitrogen fertilization contributed to easily overcome the stress conditions of water deficit stress in lucerne.

The interaction of mineral nutrition and water supply in the process of winter wheat production

In pot experiments performed in 1972-1976 with winter wheat variety 'Ilyichovka' grown at three levels of increasing mineral nutrition and at different levels of water supply (70% and 40% of maximal water capacity) an interaction was observed between mineral nutrition and water availability on the yield and some physiological characteristics of the plants. Water stress during heading stage reduced nearly by one half the grain yield per plant, mostly by decreasing the number of completely filled grains. The quicker leaf senescence and grain number reduction as well as the total grain yield due to water stress differed between the nutritional levels. The relations between leaf surface area and grain yields were nearly linear in treatments with optimal water supply, but were markedly changed by water stress.

Competition between spring barley (Hordeum vulgare L.) and italian ryegrass (Lolium multiflorum Lam.) under different water supply conditions

A pot experiment with an additive design and three series was conducted to test competition between spring barley and Italian ryegrass under different soil moisture conditions. The experimental factors were as follows: 1. type of sowing – mixed sowing and pure sowing; 2. water supply – plants supplied with water to meet their full requirements and 50% water supply reduction. The study covered five phenological development stages (BBCH) of spring barley: emergence (10–13), tillering (22–25), stem elongation (33–37), heading (52–55), and ripening (87–91). The competitive effects were evaluated based on relative yield (RY), relative yield total (RYT), competitive balance (CB), and relative efficiency index (REI). Spring barley and Italian ryegrass competed for resources throughout the growing season. Competition intensity was found to increase until the heading stage, and it decreased towards the end of the growth cycle. More intense competition was observed under reduced water supply. Spring barley dominated over Italian ryegrass from the tillering stage to the ripening stage. In mixed populations, Italian ryegrass captured the available resources more effectively than spring barley from the stem elongation stage until the end of the growing season, particularly in the treatment with optimal water supply.