Impact Of Water Availability Research Articles

Impact of Water Availability and Conservation Trends on Livestock and Community Mobilization: In Case of Yabello, Southern, Ethiopia

Impact of Water Availability and Conservation Trends on Livestock and Community Mobilization: In Case of Yabello, Southern, Ethiopia

Influence of water regime on yield components, must composition and wine volatile compounds ofVitis viniferacv. Verdejo

Background and Aims Available soil water is an important factor determining grapevine yield and grape composition. The aim of this study was to determine the impact of water availability on the yield components and the composition of must and wine of Vitis vinifera L. cv. Verdejo. Methods and Results The irrigation strategies [rainfed (R0), drip irrigated at 25% ETo (R25) and 50% ETo (R50) applied weekly from the end of the vegetative main shoot growth until harvest] were imposed on white Verdejo grapevines over three consecutive seasons (2012–2014). The 50% ETo treatment resulted in the highest yield. Increasing water availability also reduced the concentration of volatile phenols in all seasons, and of the C6 compounds in 2014 alone. The highest concentration of five individual volatile compounds was associated with the lowest water availability (R0). Conclusions High water availability increased yield and its components, mainly in the wettest season. Volatile compounds in wine were modified by water regime, with their concentration increased by the most severe deficit irrigation regime (R0). The effect of the year on must and wine composition was greater than the in-season effects of water availability treatment. Significance of the Study This study has described the effect of soil water availability on yield and its components and the composition of must and wine of Verdejo.

Shallow soils negatively affect water relations and photosynthesis in two semi-arid Eucalyptus species

Water relations of saplings of two Eucalyptus species (E. leptopoda Benth. and E. loxophleba Benth.) were investigated on engineered cover systems (soil spread over mine waste rock) with soil depths of 0.3, 0.5 and 0.7 m in a semi-arid climate during summer. Objectives were (1) to assess the influence of soil depth on plant water availability; and (2) to better understand the impact of water availability and diurnal environmental fluctuations on key physiological parameters such as transpiration (E), stomatal conductance (gs), net photosynthesis (A), intercellular CO2 concentration (Ci), and mid-day leaf water potential (ΨMD) as they relate to regulation of plant water status. Physiological responses of plants to environmental factors differed between plants in shallow versus deep soils and species. Plants on deeper soils were less affected by high vapour pressure deficit (VPD), temperature, and irradiance due to increased plant available water, partly provided by their less confined roots, resulting in higher overall gs, E, A, and ΨMD. Stomatal closure reduced A but not Ci, indicating that high temperature and radiation were also significantly contributing to the diurnal decline in A through reversible photoinhibition. Greater soil depth in natural (semi-) arid ecosystems and on constructed or restored substrates may minimise plant sensitivity to higher temperature, VPD and irradiance through plant available moisture, especially in areas most vulnerable to climate warming and drying.

Reducing Water Availability Impacts the Development of the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis MUCL 41833 and Its Ability to Take Up and Transport Phosphorus Under in Vitro Conditions.

Climate change scenarios predict a higher variability in rainfall and an increased risk of water deficits during summers for the coming decades. For this reason, arbuscular mycorrhizal fungi (AMF) and their mitigating effects on drought stress in plants are increasingly considered in crop management. However, the impact of a decrease in water availability on the development of AMF and their ability to take up and transport inorganic phosphorus (Pi) to their hosts remain poorly explored. Here, Medicago truncatula plantlets were grown in association with Rhizophagus irregularis MUCL 41833 in bi-compartmented Petri plates. The system consisted in associating the plant and AMF in a root compartment (RC), allowing only the hyphae to extend in a root-free hyphal compartment (HC). Water availability in the HC was then lowered by increasing the concentration of polyethylene glycol-8000 (PEG-8000) from 0 to 10, 25, and 50 g L-1 (corresponding to a slight decrease in water potential of -0.024, -0.025, -0.030, and -0.056 Mpa, respectively). Hyphal growth, spore production and germination were severely impaired at the lowest water availability. The dynamics of Pi uptake by the AMF was also impacted, although total Pi uptake evaluated after 24 h stayed unchanged. The percentage of metabolically active extraradical hyphae remained above 70%. Finally, at the lowest water availability, a higher P concentration was observed in the shoots of M. truncatula. At reduced water availability, the extraradical mycelium (ERM) development was impacted, potentially limiting its capacity to explore a higher volume of soil. Pi uptake was slowed down but not prevented. The sensitivity of R. irregularis MUCL 41833 to a, even small, decrease in water availability contrasted with several studies reporting tolerance of AMF to drought. This suggests a species or strain-dependent effect and support the necessity to compare the impact of water availability on morpho-anatomy, nutrient uptake and transport capacities of other, potentially more drought-tolerant (e.g., isolated from dry environments) AMF.

Some like it hot: from individual to population responses of an arboreal arid‐zone gecko to local and distant climate

AbstractAccumulating evidence has demonstrated considerable impact of climate change on biodiversity, with terrestrial ectotherms being particularly vulnerable. While climate‐induced range shifts are often addressed in the literature, little is known about the underlying ecological responses at individual and population levels. Using a 30‐yr monitoring study of the long‐living nocturnal geckoGehyra variegatain arid Australia, we determined the relative contribution of climatic factors acting locally (temperature, rainfall) or distantly (La Niña induced flooding) on ecological processes ranging from traits at the individual level (body condition, body growth) to the demography at population level (survival, sexual maturity, population sizes). We also investigated whether thermoregulatory activity during both active (night) and resting (daytime) periods of the day can explain these responses.Gehyra variegataresponded to local and distant climatic effects. Both high temperatures and high water availability enhanced individual and demographic parameters. Moreover, the impact of water availability was scale independent as local rainfall and La Niña induced flooding compensated each other. When water availability was low, however, extremely high temperatures delayed body growth and sexual maturity while survival of individuals and population sizes remained stable. This suggests a trade‐off with traits at the individual level that may potentially buffer the consequences of adverse climatic conditions at the population level. Moreover, hot temperatures did not impact nocturnal nor diurnal behavior. Instead, only cool temperatures induced diurnal thermoregulatory behavior with individuals moving to exposed hollow branches and even outside tree hollows for sun‐basking during the day. Since diurnal behavioral thermoregulation likely induced costs on fitness, this could decrease performance at both individual and population level under cool temperatures. Our findings show that water availability rather than high temperature is the limiting factor in our focal population ofG. variegata. In contrast to previous studies, we stress that drier rather than warmer conditions are expected to be detrimental for nocturnal desert reptiles. Identifying the actual limiting climatic factors at different scales and their functional interactions at different ecological levels is critical to be able to predict reliably future population dynamics and support conservation planning in arid ecosystems.

Potato aphid Macrosiphum euphorbiae performance is determined by aphid genotype and not mycorrhizal fungi or water availability.

Intra- and interspecific variation in plant and insect traits can alter the strength and direction of insect-plant interactions, with outcomes modified by soil biotic and abiotic conditions. We used the potato aphid (Macrosiphum euphorbiae Thomas) feeding on cultivated Solanum tuberosum and wild Solanum berthaulti to study the impact of water availability and plant mutualistic arbuscular mycorrhizal (AM) fungi on aphid performance and susceptibility to a parasitoid wasp (Aphidius ervi Haliday). Plants were grown under glass with live or sterile AM fungal spores and supplied with sufficient or reduced water supply. Plants were infested with 1 of 3 genotypes of M. euphorbiae or maintained as aphid-free controls; aphid abundance was scored after 1 week, after which aphid susceptibility to A. ervi was assayed ex planta. Solanum tuberosum accumulated c. 20% more dry mass than S. berthaultii, and root mass of S. berthaultii was smallest under reduced water supply in the presence of AM fungi. Aphid abundance was lowest on S. berthaultii and highest for genotype "2" aphids; genotype "1" aphid density was particularly reduced on S. berthaultii. Aphid genotype "1" exhibited low susceptibility to parasitism and was attacked less frequently than the other two more susceptible aphid genotypes. Neither AM fungi nor water availability affected insect performance. Our study suggests a fitness trade-off in M. euphorbiae between parasitism resistance and aphid performance on poor quality Solanum hosts that warrants further exploration, and indicates the importance of accounting for genotype identity in determining the outcome of multitrophic interactions.

Carbohydrate distribution during berry ripening of potted grapevines: Impact of water availability and leaf-to-fruit ratio

Insufficient leaf photoassimilation could allow mobilized carbohydrate reserves to contribute to berry sugar accumulation. However, the extent of this contribution during rapid and slow berry sugar accumulation is undefined. The potential effect of leaf-to-fruit ratio and water availability on carbohydrate reserve distribution in potted Tempranillo grapevines was examined during berry maturation. Within each leaf-to-fruit ratio treatment (full and 50% leaves), vines were grown under full or 50% reduced irrigation regimes. Dry biomass development, and the starch and soluble sugar concentrations were determined in the roots, trunks, stems and leaves. Berry sugar and anthocyanin accumulation were also assessed. Under full irrigation, no starch remobilization from roots was observed, regardless of the leaf-to-fruit ratio. Under reduced water supply, starch remobilization from roots was concurrent with rapid berry sugar accumulation, especially in grapevines with low leaf-to-fruit ratio. Soluble sugar accumulation coincided with starch depletion in the roots of grapevines under reduced water availability. When berry sugar accumulation slowed, an increase in carbohydrates was observed in the roots. Sustained water constraints during rapid berry sugar accumulation resulted in a forced reliance on stored carbohydrates to support berry sugar accumulation, but did not significantly alter the tempo of berry sugar and anthocyanin accumulation. A reduced leaf-to-fruit ratio intensified the reliance of fruit sugar accumulation on stored carbohydrates. Besides the importance of post-harvest carbohydrate reserve replenishment when root carbohydrate reserves are depleted during berry maturation, the reserves are also refilled during maturation when berry sugar accumulation slows. This study showed distinctly that root carbohydrate replenishment could already start a few weeks before harvest, and this replenishment could be important when the post-harvest carbon assimilation period is ineffective.

Essential Oil Responses to Water Stress in Greek Oregano Populations

Origanum vulgare subsp. hirtum, known as Greek oregano, has an excellent quality and good adaptability to scarcity of water, growing in several habitats of Greece and its genetic variability could be used for the production of new products. The current study aims to investigate the response of Greek oregano genotypes, originated from different mountain districts, under different water availability. The results showed that the genotypes were differentiated for dry matter production for both years. The populations “Pelion” and “Kissavos” showed superiority over the population “Olympus” by 27.2% and 18.5% respectively, for the years of experimentation. The highest essential oil yield was recorded in “Kissavos” population which showed 12.8% and 14.5% superiority over the two other populations for 2011 and 2012, respectively. The results showed the impact of water availability to the produced dry matter and essential oil yield and the interaction with the genotypes. The population “Olympus”, accumulated the highest dry matter at the irrigation level 60%, while for the populations “Pelion” and “Kissavos” the highest value was recorded at irrigation level 80%. The additional irrigation level didn’t contribute to a further production of dry matter. In conclusion, genotype and water supply can affect the dry matter, the essential oil content and yield of oregano. Oregano plants required an optimum level of irrigation to maximize the economic results, depending on the population used in this study.

Water use efficiency of fodder beet crops

Abstract In New Zealand, summer rainfall is unpredictable and usually insufficient to meet crop water requirements. The impact of water availability on yield potential of fodder beet (Beta vulgaris L.) is unknown. A single year, single site replicated field experiment investigating biomass production, water use (WU) and water use efficiency (WUE) was carried out on a deep Templeton silt loam soil at Lincoln in 2013. The experiment had four water treatments: 1: Rain fed control, 2: Full potential evapotranspiration (ETo) replaced weekly, 3: 50% of ETo replaced every 3 weeks and 4: 50% of ETo replaced weekly. Final dry matter (DM) yield differed with treatments, increasing from an average of 24 t/ha for the rain fed crops and those receiving 50% of ETo weekly to 28 t/ha for the full ETo replacement crops and those receiving 50% of ETo once every 3 weeks. Water use more than doubled with full irrigation compared with the rain fed crops (774 vs 316 mm). The WU for the intermediate crops was 483 mm. However, DM yield was higher for the treatment with 50% of ETo replaced every 3 weeks rather than weekly. Water use was related to DM yield and accounted for the observed variation (R2=0.75) in final yield. The WUE decreased with water supply, from 80 kg DM/ha/mm for the rain fed crops to 46 kg DM/ha/mm for the full ETo replacement treatments, and 64 and 57 kg DM/ha/mm for the 50% of ETo replaced weekly and every 3 weeks, respectively. Similar DM yield and marginal WUE for the full ETo treatments and those receiving 50% of ETo replaced every 3 weeks, meant that the most economic WUE was 57 kg DM/ha/mm. Although these results are from a single and site, they suggest that full ETo replacement was uneconomic in this type of soil and therefore partial irrigation to 50% of ETo replaced every 3 weeks may be the optimum for this type of soil. It is recommended to investigate similar treatments on shallow and stony soils. Keywords: Beta vulgaris L., evapotranspiration, water use, water use efficiency, water extraction pattern, water extraction depth.

Water and growth in an agricultural economy

AbstractWe present a model of economic growth of an agricultural household that is faced with an exogenous water availability constraint. We examine the long‐run investment and consumption choices under two scenarios: (i) when the water availability constraint is binding and (ii) when it is not binding. We then compare the two scenarios to derive conditional convergence hypotheses regarding the impact of water availability on long‐run agricultural growth. Panel data from Wyoming are used to test these conditional convergence hypotheses. We find that Wyoming counties exhibit strong conditional convergence in agricultural growth. Our theoretical and empirical results demonstrate that water availability is not a determinant but can be a constraint on long‐run agricultural growth. Higher water use leads to higher growth in agricultural yield per capita but when water rights constrain water use in a county, as we found in southeastern Wyoming, there are significant losses in agricultural growth.

Soil water potential does not affect leaf morphology or cuticular characters important for palaeo-environmental reconstructions in southern beech, Nothofagus cunninghamii (Nothofagaceae)

Leaf form is closely related to local prevailing abiotic conditions and thus the morphology of fossil and sub-fossil leaves is often used to reconstruct both historical and palaeo-environmental conditions. However, palaeo-environmental reconstruction is difficult because leaf form is controlled potentially by many interacting environmental factors such as temperature, CO2 concentration, light and water availability. We used a glasshouse trial to investigate the impact of water availability on the leaf and cuticle morphology of a species important for palaeo-environmental reconstruction, the southern beech, Nothofagus cunninghamii. We found that reducing soil water potential to –0.2 or –0.5 MPa had no impact on leaf form or cuticular characters, despite reducing leaf carbon assimilation and severely restricting plant growth. Although plant accession affected many leaf characters, there were few significant impacts of altitude of origin and no substantial interactions between altitude of origin and soil water potential. Thus, both cuticular and gross leaf morphology seem to be stable across a range of soil water potentials in this species, meaning that palaeo-environmental signals from this species are unlikely to be affected by changes in water availability.

Exploring the Water-Thermoelectric Power Nexus

AbstractIn 2005, thermoelectric power accounted for 41% of all freshwater withdrawals and roughly 3% of all consumptive use in the United States. With the demand for electricity projected to increase by 24% by 2035 concerns have been raised as to the availability of water for this growing industry; particularly, as the siting of several new thermoelectric facilities have been challenged on the basis of water supply. To address this concern we estimate the potential impact of water availability on future expansion of the thermoelectric power industry. Specifically, both the extent and location of thermoelectric developments at risk due to limited fresh water supply is estimated for a variety of alternative energy futures that differ according to the assumed mix of fuels utilized in new plant construction. According to the analyzed scenarios water consumption for thermoelectric power generation is projected to increase by 36–43% between 1995 and 2035, with much of this development expected to occur in basin...

Impact of Water Availability on Land and Water Productivity: A Temporal and Spatial Analysis of the Case Study Region Khorezm, Uzbekistan

Since irrigation water is assumedly the predominant factor determining crop yield, the difference in irrigation water availability across the administrative sub-districts of the Khorezm region, Central Asia, also inflicts an unequal distribution of agricultural revenues. Considering the national aim of a fair distribution and efficient use of resources, here we analyze the relationships between irrigation water access and rural welfare from 2000 to 2007 by descriptive statistics. Analyses revealed not only the general dependency of agricultural revenue on irrigation water availability, but also occurrence of low land productivity during water scarce years and, irrespective of the annual water availability, in some tail end regions each year. Furthermore, apart from irrigation water availability, land productivity was also impacted by soil quality, cropping structure, and type of land ownership. Fair distribution of water and land resources should also take into consideration population density. It is argued that an anticipated equal and efficient water allocation necessitates improved irrigation water conveyance, distribution, and application efficiency via best water management practices. Liberalization of markets, development of a market infrastructure and improvement in yields also contribute to increased land and water productivity.

Impact of water availability on winter wheat ( Triticum aestivum L.) yield characteristics

Water supply of crop plants is the most essential physiological condition influencing quality and quantity performance of grain yield. In a 12-year experimental series of winter wheat agronomic trials run at the Nagygombos experimental site (Hungary) the effect of water availability has been studied. The location represents the typical average lowland conditions of the country, the annual precipitation of the experimental site belonging to the 550–600 mm belt of the Northern edges of the Great Hungarian Plain, while the average depth of groundwater varies between 2 to 3 metres. Crop years with various precipitation patterns have had different impacts on crop yield quality and quantity. Yield figures were in positive correlation with annual precipitation in general. Water availability had diverse influence on quality manifestation. Good water supply has often resulted in poorer grain quality, especially wet gluten and Hagberg values have been affected by that. Drought reduced the amount of yield in general, but contributed to a better quality manifestation in some of the crop years.

Climate change and EU legal initiatives regarding water availability

AbstractDiscussions on climate change legislation concentrate on measures relating to the emission of greenhouse gases. The present contribution tries to have a look at the impact of water availability within the European Union and to examine the need for EU legislation in this area, starting from the fact that the EU has, until now, not considered water availability to be a topic which deserves specific attention by the Union. The articles points at the serious impact which water scarcity is likely to have in particular, though not exclusively, in Southern European countries and passes in review a number of possible options for EU wide legislation.

Culturable Escherichia coli in Soil Mixed with Two Types of Manure

We evaluated the impact of the manure type used in soil–manure mixtures on the detection of culturable E. coli as tested in water quality monitoring. A series of incubation experiments, lasting up to 200 d, allowed evaluation of the potential impact of manure × soil interactions on the augmentation of culturable E. coli Two soil types (sandy loam and a silt loam), two manure types (liquid swine manure and solid beef cattle manure), and three temperature levels (4, 12, and 20°C) were investigated. The significance of the presence of competing microorganisms was estimated by comparing results from manure mixtures with sterile and nonsterile soils. Water content in the soil–manure mixtures was maintained close to field capacity to eliminate the specific impact of water availability. We found that culturability of the indicator organism, E. coli, changed with time and was dependent on the type of manure used and its interaction with soil. Escherichia coli could be cultured for a longer time from soils with liquid manure additions. Whereas E. coli numbers were initially higher from soils treated with solid beef cattle manure, their numbers decreased more rapidly and the duration of their apparent survival was shorter. Resilience of culturable E. coli was independent of their initial numbers in manure.

Management of environmental crop conditions to produce useful sunflower oil components

AbstractThe objective of this study was to investigate the impact of water availability and temperature after flowering on oil, major fatty acid and sterol contents in seeds of standard and oleic sunflower genotypes, under managed and controlled field conditions. When water deficit was effective from the beginning to the end of anthesis, it modified the fatty acid composition of standard hybrids. When water was supplied, a major enhancement of oleic acid content was associated with a concomitant reduction of linoleic acid content and a decrease in saturated fatty acid contents. Higher temperatures increased the oleic acid content in seeds of standard hybrids. Oil content was enhanced under colder temperature and irrigation. The content of minor oil components, phytosterols, was also enhanced when seed development occurred under high temperature and severe water stress. As a whole, the data showed that combining water management, sowing date and choice of genotype may orientate the biosynthesis of seed components and thus generate seed composition variability suitable for industrial purposes.

δ13C variation of C3 and C4 plants across an Asian monsoon rainfall gradient in arid northwestern China

AbstractWe have investigated carbon isotopic compositions of four plant genus/species, Bothriochloa ischaemum (C4), Stipa bungeana (C3), Lespedeza sp. (C3) and Heteropappus less (C3), along a precipitation gradient in northwest China in order to assess the impact of water availability on the carbon isotopic discrimination against 13C during carbon assimilation in this area. This information is necessary for reconstruction of paleovegetation, particularly paleo‐C3/C4 plant ratios using δ13C value of organic matter in loess and paleosols in the Chinese Loess Plateau. The δ13C of C3 plants, as a group, exhibits a negative correlation with the annual precipitation amount with a total change and sensitivity of 5‰ and −1.1‰/100 mm, respectively, for the precipitation range from 200 to 700 mm. The C4 grass, B. ischaemum responds to aridity by decreasing 1.7‰ for over the precipitation range from 350 to 700 mm; the plant δ13C is significantly correlated with annual precipitation with a slope −0.61‰/100 mm. This result implies that without considering the effect of water availability on the plant δ13C values, reconstruction of percent C4 vegetation during the last glaciation can be overestimated by about a factor of two.

Competition among three dune species: the impact of water availability on below–ground processes

We studied competitive interactions among three species (Corynephorus canescens, Hieracium pilosella and Carex arenaria) of different early successional stages on sand dunes. Our study focused on the influence of competition and water availability on biomass allocation patterns and the plasticity of root responses. Plants were grown for one growing season in a simple additive (target–neighbour) design under low or ambient water supply. Overall competition intensity (e.g., above–and below–ground), as well as root competition alone, were compared using control plants grown without competitors. Our results show high competition intensity leading to an average target plant biomass reduction of 56 relative to controls. Competition was mostly below–ground. With increasing water availability, the competitive effect of H. pilosella on both of the other species decreased significantly. All other tested species combinations were not influenced by water availability. Soil moisture seemed to be a key factor determining the plasticity of root responses. Under limited water availability, strong competitors caused a significant decrease of response ratio (lnRR) based on root: shoot ratios for H. pilosella and C. arenaria and a decrease in lnRR based on specific root length (SRL) for C. arenaria. Under sufficient water supply, however, there was no significant effect of competition on root: shoot ratios for any of the species and only C. arenaria in competition with C. canescens showed a lower lnRR based on SRL. These water–related, species–specific changes of root morphology and allocation patterns may point to an adaptive response to competition.

Irrigation scheduling of confectionery groundnut (Arachis hypogeaea L.) in Senegal using a simple water balance model

The sustainability of the groundnut production in North of Senegal hydro-agricultural systems depends on the development of irrigation methods which guarantee yield, quality and meet best water management practices. To achieve this goal, a water balance model taking into account plant development and soil water status was developed. The proposed model expresses evapotranspiration as a function of the observed leaf area index (LAI) and simulated soil water status. Compared to classical tools, mostly based on crop coefficients, the conceptual advantage of the developed model is to take into account not only the impact of water availability on leaf development of the crop but also their incidence on transpiration. Irrigation scheduling consists of determining net irrigation levels by adjusting the fraction of transpirable soil water (FTSW). The model was first calibrated and validated using experiments carried out in 1994, 1996 and 2000, on two groundnut varieties, Fleur 11 and GH 119-20, at the experimental station of Bambey in Senegal, using sprinkler irrigation methods. The model was then applied in 2000 during the dry season to the Senegal river valley under drip irrigation conditions so as to schedule irrigation according to diverse situations of water resource availability. Evidence was made of the model capacity to devise a sustainable irrigation method which guarantees yield, quality and appropriate water management practices.