Assessing the Impact of Management Strategies on Water Use Efficiency Using Soil-Plant-Atmosphere Models

Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO2 and H2O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO2 and H2O flux control should help researchers understand and simulate future functional adjustments in these ecosystems.

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Effects of Temperature and Grafting on Yield, Nutrient Uptake, and Water Use Efficiency of a Hydroponic Sweet Pepper Crop

Agronomy ◽

10.3390/agronomy9020110 ◽

2019 ◽

Vol 9 (2) ◽

pp. 110 ◽

Cited By ~ 6

Author(s):

Andreas Ropokis ◽

Georgia Ntatsi ◽

Constantinos Kittas ◽

Nikolaos Katsoulas ◽

Dimitrios Savvas

Keyword(s):

Water Use Efficiency ◽

Nutrient Uptake ◽

Water Use ◽

Total Yield ◽

Sweet Pepper ◽

Winter Climate ◽

Mild Winter ◽

Yield Increase ◽

Use Efficiency ◽

The Impact

In areas characterized by mild winter climate, pepper is frequently cultivated in unheated greenhouses in which the temperature during the winter may drop to suboptimal levels. Under low temperature (LT) conditions, the uptake of nutrients may be altered in a different manner than that of the water and thus their uptake ratio, known as uptake concentration, may be different than in greenhouses with standard temperature (ST) conditions. In the present study, pepper plants of the cultivars “Sammy” and “Orangery”, self-grafted or grafted onto two commercial rootstocks (“Robusto” and “Terrano”), were cultivated in a greenhouse under either ST or LT temperature conditions. The aim of the study was to test the impact of grafting and greenhouse temperature on total yield, water use efficiency, and nutrient uptake. The LT regime reduced the yield by about 50% in “Sammy” and 33% in “Orangery”, irrespective of the grafting combination. Grafting of “Sammy” onto both “Robusto” and “Terrano” increased the total fruit yield by 39% and 34% compared with the self-grafted control, while grafting of “Orangery” increased the yield only when the rootstock was “Terrano”. The yield increase resulted exclusively from enhancement of the fruit number per plant. Both the water consumption and the water use efficiency were negatively affected by the LT regime, however the temperature effect interacted with the rootstock/scion combination. The LT increased the uptake concentrations (UC) of K, Ca, Mg, N, and Mn, while it decreased strongly that of P and slightly the UC of Fe and Zn. The UC of K and Mg were influenced by the rootstock/scion combination, however this effect interacted with the temperature regime. In contrast, the Ca, N, and P concentrations were not influenced by the grafting combination. The results of the present study show that the impact of grafting on yield and nutrient uptake in pepper depend not merely on the rootstock genotype, however on the rootstock/scion combination.

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Using market research to understand the adoption of irrigation management strategies in the stone and pome fruit industry

Australian Journal of Experimental Agriculture ◽

10.1071/ea01183 ◽

2005 ◽

Vol 45 (9) ◽

pp. 1181 ◽

Cited By ~ 14

Author(s):

G. Kaine ◽

D. Bewsell ◽

A. Boland ◽

C. Linehan

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Market Research ◽

Management Practices ◽

Irrigation Management ◽

Management Strategies ◽

Pome Fruit ◽

Managerial Flexibility ◽

Use Efficiency ◽

Extension Program

Market research was conducted to develop an extension program targeting the specific irrigation management needs of growers in the stone and pome fruit industry within the Goulburn Valley, Victoria. The process of integrating market research with extension practice proved challenging, as it required the development of an extension program that was fundamentally different from what was originally envisaged. However, it was essential to achieve this integration in order to meet the original objectives for the extension program as set by the funding body. We found, in most cases, that the motivation for stone and pome fruit growers in the Goulburn Valley to change orchard irrigation management practices was not because they needed to save water, or to increase water use efficiency. Instead, growers were changing practices in order to save time irrigating, improve the scope for managerial flexibility in the orchard, or when redeveloping their orchard to a closer planting design. These findings suggest that growers in the Goulburn Valley are more likely to respond to an extension program consistent with these motivations rather than a program promoting water use efficiency.

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Daily dynamics of photosynthetic parameters in beech population under periodical drought conditions

Open Life Sciences ◽

10.1515/biol-2015-0022 ◽

2015 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Milan Borišev ◽

Rita Horak ◽

Slobodanka Pajević ◽

Saša Orlović ◽

Nataša Nikolić ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Soil Drought ◽

Physiological Status ◽

Photosynthetic Parameters ◽

Soil Layers ◽

Photosynthetic Productivity ◽

Early Afternoon ◽

Use Efficiency ◽

The Impact

AbstractThe paper presents the impact of periodic soil drought on physiological parameters important for bioproductivity of mountain beech populations. The investigated forest population was located near Fruška gora mountain peak, where water runs off quickly, and consequently lack of soil humidity develops very often. Decreasing trends of photosynthesis, transpiration, water use efficiency and stomatal conductance (gs) during the growing season were evident, in correlation with a shortage of precipitation. Diurnally, photosynthesis of beech leaves showed rhythmical changes. It was the most intensive in the morning, then decreased between noon and 1 pm, and increased again during early afternoon. High leaf temperature and water deficit in the deeper soil layers caused a decreasing trend in photosynthesis and daily rhythmic changes of the transpiration rate and water use efficiency. Although surface soil water capacity did not show a significant decreasing trend from July to September, a lack of precipitation was observed, which probably caused a lack of moisture in deeper soil layers, resulting in a decline in photosynthesis and transpiration. Physiological status, linked to primary photosynthetic productivity of forests, could be a significant indicator of environmental conditions and trends in climate changes.

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Modeling Irrigation Management Strategies to Maximize Cotton Lint Yield and Water Use Efficiency

Agronomy Journal ◽

10.2134/agronj2008.0041xs ◽

2009 ◽

Vol 101 (3) ◽

pp. 460-468 ◽

Cited By ~ 26

Author(s):

R. L. Baumhardt ◽

S. A. Staggenborg ◽

P. H. Gowda ◽

P. D. Colaizzi ◽

T. A. Howell

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Irrigation Management ◽

Management Strategies ◽

Lint Yield ◽

Cotton Lint ◽

Cotton Lint Yield ◽

Use Efficiency

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Fertigation Strategies for Improving Water Use Efficiency and Limiting Nutrient Loss in Soilless Hippeastrum Production

HortScience ◽

10.21273/hortsci.51.6.684 ◽

2016 ◽

Vol 51 (6) ◽

pp. 684-689 ◽

Cited By ~ 6

Author(s):

Youssef Rouphael ◽

Giampaolo Raimondi ◽

Rosanna Caputo ◽

Stefania De Pascale

Keyword(s):

Plant Growth ◽

Water Use Efficiency ◽

Water Use ◽

Water Relations ◽

Nutrient Solution ◽

Nutrient Management ◽

Growth Parameters ◽

Management Strategies ◽

Nutrient Loss ◽

Use Efficiency

Implementing nutrient management strategies in soilless culture, which improve water use efficiency (WUE) and limit the loss of eutrophying elements without affecting crop performance, is a priority for the floriculture industry. The aim of the current research was to assess the effect of two nutrient management strategies, based on electrical conductivity (EC) or nitrate-nitrogen (N-NO3−) concentration control on plant growth, ornamental quality, plant–water relations, mineral composition, and WUE of greenhouse Hippeastrum grown in semiclosed soilless system. The recirculating nutrient solution was discharged whenever a threshold EC value of 3.0 dS·m−1 was reached (EC-based strategy), or when N-NO3− concentration decreased below the limit of 1.0 mol·m−3 (nitrate-based strategy). There were no significant differences in terms of plant growth parameters, stomatal resistance, leaf water relations, and macronutrient composition in plant tissues between the two nutrient management strategies. In the EC- and the nitrate-based strategies, the recirculating nutrient solution was flushed 10 and 5 times, respectively. The water loss (WL) and the total water use (Wuse) in the EC-based strategy were significantly higher by 261.1% and 61.5%, respectively, compared with the N-NO3−-based strategy. In contrast with the EC-based strategy, the adoption of the N-NO3−-based strategy significantly minimized the nitrate, phosphate, and potassium emissions to the environment. The effective WUE of the system (WUES) recorded in the N-NO3−-based strategy was higher by 55.9% compared with the one recorded with the EC-based strategy.

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Evaluation of Water Use Efficiency of 31 Provinces and Municipalities in China Using Multi-Level Entropy Weight Method Synthesized Indexes and Data Envelopment Analysis

Sustainability ◽

10.3390/su11174556 ◽

2019 ◽

Vol 11 (17) ◽

pp. 4556 ◽

Cited By ~ 5

Author(s):

Boyang Sun ◽

Xiaohua Yang ◽

Yipeng Zhang ◽

Xiaojuan Chen

Keyword(s):

Data Envelopment Analysis ◽

Water Use Efficiency ◽

Water Use ◽

Water Shortage ◽

Data Envelopment ◽

Entropy Weight ◽

Entropy Weight Method ◽

Weight Method ◽

Use Efficiency ◽

The Impact

China’s water shortage problem is becoming increasingly severe. Improving water use efficiency is crucial to alleviating China’s water crisis. This paper evaluates the water use efficiency of 31 provinces and municipalities in China by using the data envelopment analysis (DEA) method. When the usual DEA model has too many indexes selected, it will cause the majority of the decision making units (DMUs) efficiency values be one, which leads to invalid evaluation results. Therefore, by using the entropy weight method, a new synthetic set of indexes is constructed based on the original indexes. The new synthetic set of indexes retains the full information of the original indexes, and the goal of simplifying the number of indexes is achieved. Simultaneously, by empowering the original indexes, the evaluation using synthetic indexes can also avoid the impact of industrial structure and labor division on water use efficiency. The results show that in China’s northeastern grain producing areas, water use efficiency is higher due to the high level of agricultural modernization. The provinces in the middle reaches of the Yangtze River have the lowest water use efficiency due to water pollution and water waste. In general, China’s overall water use efficiency is low, and there is still much room for improvement.

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Foliar application of triacontanol ameliorates heat stress through regulation of the antioxidant defense system and improves yield of eggplant

Brazilian Journal of Biology ◽

10.1590/1519-6984.253696 ◽

2024 ◽

Vol 84 ◽

Author(s):

H. Faiz ◽

O. Khan ◽

I. Ali ◽

T. Hussain ◽

S. T. Haider ◽

...

Keyword(s):

Heat Stress ◽

Water Use Efficiency ◽

Water Use ◽

Foliar Application ◽

Block Design ◽

Solanum Melongena ◽

Control Treatment ◽

Yield And Quality ◽

Use Efficiency ◽

The Impact

Abstract Transplanting time and genotype contribute to improving crop yield and quality of eggplant (Solanum melongena L.). A field experiment was conducted to investigate the impact of foliar applied of triacontanol (TRIA) and eggplant genotypes 25919, Nirala, 28389 and Pak-10927,transplanted on 1 March,15 March, and 1 April on exposure to high air temperature conditions. The experiment was performed according to Randomized Complete Block Design and the data was analyzed by using Tuckey,s test . The TRIA was applied at 10µM at flowering stage; distilled water was used as the control. Rate of photosynthesis and transpiration, stomatal conductance, water use efficiency, and effects on antioxidative enzymes (superoxide dismutase, catalase and peroxidase) were evaluated. The 10µM TRIA increased photosynthesis rate and water use efficiency and yield was improved in all genotypes transplanted at the different dates. Foliar application of 10µM TRIA increased antioxidative enzyme activities (SOD, POD & CAT) and improved physiological as well as biochemical attributes of eggplant genotypes exposed to high heat conditions. Highest activity of dismutase enzyme 5.41mg/1g FW was recorded in Nirala genotype in second transplantation. Whereas, lowest was noted in PAK-10927 (2.30mg/g FW). Maximum fruit yield was found in accession 25919 (1.725kg per plant) at 1st transplantation with Triacontanol, whereas accession PAK-10927 gave the lowest yield (0.285 kg per plant) at control treatment on 3rd transplantation. Genotype, transplanting date and application of TRIA improved growth, yield and quality attributes under of heat stress in eggplant.

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Potassium application to alleviate drought stress in cassava production: A growth chamber based carbon-13 pulse labelling experiment

10.5194/egusphere-egu2020-4839 ◽

2020 ◽

Author(s):

Jonas Van Laere ◽

Annemie Willemen ◽

Yang Ding ◽

Hami Said ◽

Christian Resch ◽

...

Keyword(s):

Drought Stress ◽

Water Use Efficiency ◽

Water Use ◽

Critical Role ◽

Starch Synthesis ◽

Growth Chamber ◽

Pulse Labelling ◽

Use Efficiency ◽

The Impact ◽

Translocation Speed

It is predicted that climate change will cause an increase in frequency and duration of dry spells in Central Africa. This will lower yields of cassava (Manihot esculenta Crantz), a starchy root crop consumed daily by almost 800 million people in the tropics. Potassium has been considered as an important plant nutrient in mitigating the impact of drought stress because of its critical role in stomatal regulation, as an osmolyte, as well as in starch synthesis and assimilate translocation. This study aims to quantify the effects of potassium fertilizer on water use efficiency and translocation speed of new assimilates in water-stressed cassava plants at early bulking stage.Cassava cuttings (Bailo variety), originating from the Eastern Democratic Republic of Congo, were grown in pots filled with 5 kg of calcium carbonate free sand substrate and fertilized with a complete nutrient solution either high (+K; 1.437 mM K+) or low (-K; 0.359 mM K+) in potassium. All pots were weighed every other to each day to monitor water use and were watered to field capacity. A drought treatment was imposed on half of the plants two months after planting by reducing irrigation amounts by half. Plants were put in an airtight walk-in growth chamber enriched with 13C-CO2 (for 8 h) to trace the translocation of new assimilates. One, nine and twenty-four days after labelling, plants were harvested and &#948;13C values for different plant organs were analysed.Plant water use was higher in plants under low potassium nutrition (-K) in the period prior to imposition of drought. Data on biomass production and &#948;13C and &#948;18O values of these plants will further help understand whether the observed difference in water use also leads to a difference in water use efficiency. Further, a 13C mass balance will be composed. These data, to be presented at EGU 2020, will provide information on the translocation speed of new assimilates from shoot to root and confirm whether potassium positively affects this process under dry conditions.

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