Water-use efficiency of dryland canola in an equi-seasonal rainfall environment

2005 ◽  
Vol 56 (12) ◽  
pp. 1373 ◽  
Author(s):  
Michael J. Robertson ◽  
John A. Kirkegaard
Keyword(s):  
Water Supply ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Seasonal Rainfall ◽  
Annual Rainfall ◽  
Maximum Efficiency ◽  
Rainfall Distribution ◽  
Potential Yield ◽  
Use Efficiency

The French and Shultz approach that relates seasonal rainfall to potential yield in wheat has yet to be applied to dryland canola. Relationships were derived between grain yield of 42 experimental crops (yield range 0.5–5.4 t/ha) free of weeds, pests, diseases, and nutrient deficiencies in southern New South Wales, and various measures of observed (rainfall, available soil water) and simulated (evapotranspiration) seasonal water supply. April to October rainfall and in-crop rainfall were the poorest predictors of yield (R2 < 0.5). By adjusting in-crop rainfall to account for stored soil water at sowing and that remaining at harvest (termed ‘seasonal water supply’), 68% of the variance in yield could be explained. Estimates derived using the APSIM-Canola simulation model or simulated totals of evapotranspiration or transpiration explained 73–82% of the variance. The slope of the regression line between yield of the 42 crops, which simulation indicated had all yielded to their water-limited potential, and seasonal water supply (termed here the water-use efficiency for grain production, WUE) was 11 kg/ha.mm above an intercept of 120 mm. WUE varied from 4 to 18 kg/ha.mm and the upper boundary for WUE in those seasons where rainfall distribution facilitated maximum efficiency was 15 kg/ha.mm. Long-term simulations, conducted at locations with mean annual rainfall of 430–660 mm, confirmed the variability of WUE due to rainfall distribution and also that WUE would be expected to decline, on average, by one-third between sowings in early April and early July. This necessitates caution in accepting a single WUE value as an indicator of agronomic constraints to yield. For the purposes of practical application by farmers and advisors, water-limited potential yield can be calculated in the region as a function of seasonal water supply minus 120 mm up to a limit of 450 mm, beyond which potential yield is not limited by water. Available soil water at sowing can be estimated from summer fallow rainfall above a threshold of 80 mm, and water remaining at harvest can be estimated from post-anthesis rainfall above a threshold of 50 mm. This improved method for estimating water-limited potential yield in canola retains the ease of use of the French and Shultz approach, so that other constraints to yield can be more accurately diagnosed in dryland environments by farmers and advisors.

Water demand and water use efficiency of winter barley in Hungary

2011 ◽  
Vol 59 (1) ◽  
pp. 13-22
Author(s):  
Z. Varga-Haszonits ◽  
E. Enzsölné Gerencsér ◽  
Z. Lantos ◽  
Z. Varga
Keyword(s):  
Soil Moisture ◽  
Water Supply ◽  
Water Use Efficiency ◽  
Water Use ◽  
Potential Evapotranspiration ◽  
Growth Period ◽  
Winter Barley ◽  
Potential Yield ◽  
Yield Data ◽  
Use Efficiency

The temporal and spatial variability of soil moisture, evapotranspiration and water use were investigated for winter barley. Evaluations were carried out on a database containing meteorological and yield data from 15 stations. The spatial distribution of soil moisture, evapotranspiration and water use efficiency (WUE) was evaluated from 1951 to 2000 and the moisture conditions during the growth period of winter barley were investigated. The water supply was found to be favourable, since the average values of soil moisture remained above the lower limit of favourable water content throughout the growth period, except for September–December and May–June. The actual evapotranspiration tended to be close to the potential evapotranspiration, so the water supplies were favourable throughout the vegetation period. The calculated values of WUE showed an increasing trend from 1960 to 1990, but the lower level of agricultural inputs caused a decline after 1990. The average values of WUE varied between 0.87 and 1.09 g/kg in different counties, with higher values in the northern part of the Great Hungarian Plain. The potential yield of winter barley can be calculated from the maximum value of WUE. Except in the cooler northern and western parts of the country, the potential yield of winter barley, based on the water supply, could exceed 10 t/ha.

scholarly journals Water Use Efficiency Current Status Assessment in the Context of WATenERgy CYCLE Project

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 602
Author(s):  
Stavroula Tsitsifli ◽  
Anastasia Papadopoulou ◽  
Vasilis Kanakoudis ◽  
Konstantinos Gonelas
Keyword(s):  
Water Supply ◽  
Water Use Efficiency ◽  
Water Use ◽  
Methodological Approach ◽  
National Level ◽  
Water Utilities ◽  
Current Status ◽  
Water Supply Systems ◽  
Use Efficiency ◽  
Supply Systems

Water use efficiency is a crucial issue in drinking water utilities as it is connected to environmental and economic consequences. WATenERgy CYCLE project aims at developing a methodological approach towards efficient and effective transnational water and energy resources management in the Balkan–Mediterranean area. The paper presents the results of performance evaluation of the water supply systems of the water utilities involved in the project, both at local and national level. The methodology used in the water balance and performance indicators as well as data on the operational status of the water supply systems. The results showed that Non-Revenue Water is one of the major problems addressed.

Potential yield and water-use efficiency benefits in sorghum from limited maximum transpiration rate

2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Simulation Analysis ◽  
Stomatal Closure ◽  
Risk Attitude ◽  
Potential Yield ◽  
Yield Increase ◽  
Use Efficiency ◽  
Yield Responses

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.

scholarly journals Yield, water use efficiency, and yield response factor in carrot crop under different irrigation depths

2016 ◽  
Vol 46 (7) ◽  
pp. 1145-1150 ◽  
Author(s):  
Daniel Fonseca de Carvalho ◽  
Dionizio Honório de Oliveira Neto ◽  
Luiz Fernando Felix ◽  
José Guilherme Marinho Guerra ◽  
Conan Ayade Salvador
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Block Design ◽  
Time Domain Reflectometry ◽  
Yield Response ◽  
Response Factor ◽  
Use Efficiency ◽  
The Mean ◽  
Yield Response Factor

ABSTRACT: The aim of the present study was to evaluate the effect of different irrigation depths on the yield, water use efficiency (WUE), and yield response factor (Ky) of carrot (cv. 'Brasília') in the edaphoclimatic conditions of Baixada Fluminense, RJ, Brazil. Field trials were conducted in a Red-Yellow Argisol in the 2010-2011period. A randomized block design was used, with 5 treatments (depths) and 4 replicates. Depths were applied by drippers with different flow rates, and the irrigation was managed by time domain reflectometry (TDR) technique. The reference (ETo) and crop (ETc) evapotranspiration depths reached 286.3 and 264.1mm in 2010, and 336.0 and 329.9mm in 2011, respectively. The root yield varied from 30.4 to 68.9t ha-1 as a response to treatments without irrigation and 100% replacement of the soil water depth, respectively. Values for WUE in the carrot crop varied from 15 to 31kg m-3 and the mean Ky value was 0.82. The mean values for Kc were obtained in the initial (0.76), intermediate (1.02), and final (0.96) stages. Carrot crop was influenced by different water depths (treatments) applied, and the highest value for WUE was obtained for 63.4% of soil water replacement.

scholarly journals Water Deficit Modulates the CO2 Fertilization Effect on Plant Gas Exchange and Leaf-Level Water Use Efficiency: A Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Li ◽  
Dagang Guo ◽  
Xiaodong Gao ◽  
Xining Zhao
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Future Climate Change ◽  
Leaf Level ◽  
Fertilization Effect ◽  
Use Efficiency ◽  
Stimulation Of

Elevated atmospheric CO2 concentrations ([eCO2]) and soil water deficits significantly influence gas exchange in plant leaves, affecting the carbon-water cycle in terrestrial ecosystems. However, it remains unclear how the soil water deficit modulates the plant CO2 fertilization effect, especially for gas exchange and leaf-level water use efficiency (WUE). Here, we synthesized a comprehensive dataset including 554 observations from 54 individual studies and quantified the responses for leaf gas exchange induced by e[CO2] under water deficit. Moreover, we investigated the contribution of plant net photosynthesis rate (Pn) and transpiration rates (Tr) toward WUE in water deficit conditions and e[CO2] using graphical vector analysis (GVA). In summary, e[CO2] significantly increased Pn and WUE by 11.9 and 29.3% under well-watered conditions, respectively, whereas the interaction of water deficit and e[CO2] slightly decreased Pn by 8.3%. Plants grown under light in an open environment were stimulated to a greater degree compared with plants grown under a lamp in a closed environment. Meanwhile, water deficit reduced Pn by 40.5 and 37.8%, while increasing WUE by 24.5 and 21.5% under ambient CO2 concentration (a[CO2]) and e[CO2], respectively. The e[CO2]-induced stimulation of WUE was attributed to the common effect of Pn and Tr, whereas a water deficit induced increase in WUE was linked to the decrease in Tr. These results suggested that water deficit lowered the stimulation of e[CO2] induced in plants. Therefore, fumigation conditions that closely mimic field conditions and multi-factorial experiments such as water availability are needed to predict the response of plants to future climate change.

Water use efficiency of wheat in a Mediterranean-type environment. II. some limitations to efficiency

1984 ◽  
Vol 35 (6) ◽  
pp. 765 ◽  
Author(s):  
RJ French ◽  
JE Schultz
Keyword(s):  
Water Use Efficiency ◽  
Leaf Area ◽  
Water Use ◽  
Harvest Index ◽  
Field Experiments ◽  
Field Trials ◽  
Growth Yields ◽  
Potential Yield ◽  
Use Efficiency ◽  
Factorial Treatments

Evidence is presented that water use efficiency and yield of wheat are reduced by insufficient leaf area and by inadequate content of nutrients in the top growth. Yields from field trials are compared with the potential yield, and a review is made of the limitations caused by weeds, the incidence of diseases and the harvest index. The data highlight the need for field experiments to define the evaporation and transpiration components of water use in each environment. They also indicate the need for multi-factorial treatments to overcome all yield limitations and thereby attain the potential yield.

scholarly journals Interannual and Seasonal Variations in Ecosystem Transpiration and Water Use Efficiency in a Tropical Rainforest

Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Maricar Aguilos ◽  
Clément Stahl ◽  
Benoit Burban ◽  
Bruno Hérault ◽  
Elodie Courtois ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Seasonal Variations ◽  
Radiation Effects ◽  
Global Radiation ◽  
Climate Conditions ◽  
Carbon Cycles ◽  
Use Efficiency ◽  
The Impact

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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