High crop productivity with high water use in winter and summer on the Liverpool Plains, eastern Australia

2008 ◽  
Vol 59 (4) ◽  
pp. 303 ◽  
Author(s):  
R. R. Young ◽  
P.-J. Derham ◽  
F. X. Dunin ◽  
A. L. Bernardi ◽  
S. Harden

We report exceptional productivity and associated water-use efficiency across seasons for commercial crops of rainfed spring wheat and grain sorghum growing on stored soil water in Vertosols on the Liverpool Plains, central-eastern Australia. Agreement between the independently measured terms of evapotranspiration (ET) and the soil water balance (in-crop rainfall + δsoil water) was achieved within acceptable uncertainty across almost all measurement intervals, to provide a reliable dataset for the analysis of growth and water-use relationships without the confounding influence of water outflow either overland or within the soil. Post-anthesis intrinsic transpiration efficiency (kc ) values of 4.7 and 7.2 Pa for wheat and sorghum, respectively, and grain yields of 8 and 7 t/ha from ET of 450 and 442 mm (1.8 and 1.6 g/m2.mm), clearly demonstrate the levels of productivity and water-use efficiency possible for well-managed crops within an intensive and productive response cropping sequence. The Vertosols in which the crops were grown enabled rapid and apparently unconstrained delivery of significant quantities of subsoil water (34% and 51% of total available) after anthesis, which enabled a doubling of pre-anthesis standing biomass and harvest indices of almost 50%. Durum wheat planted into only 0.30 m of moist soil and enduring lower than average seasonal rainfall, yielded less biomass and grain (2.3 t/ha) with lower water-use efficiency (0.95 g/m2.mm) but larger transpiration efficiency, probably due to reduced stomatal conductance. We argue that crop planting in response to stored soil water and management for high water-use efficiency to achieve high levels of average productivity of crop sequences over time can have a significant effect on both increased productivity and enhanced hydrological stability across alluvial landscapes.

1986 ◽  
Vol 13 (4) ◽  
pp. 523 ◽  
Author(s):  
JM Morgan ◽  
AG Condon

Genotypic differences in turgor maintenance in wheat were shown to be associated with differences in grain yield in the field at both high and Low water deficits. High water deficits were produced by growing plants in field plots using water stored in the soil at sowing, and excluding rain with a rain cover. At low water deficits plants received rainfall, and irrigation was supplied before and immediately after sowing, at tillering, at jointing, at ear emergence, and during grain filling. Yield differences were analysed in terms of harvest index, water use, and water use efficiency. Water use was calculated from changes in soil water contents. At high water deficits all three factors were associated with differences in turgor maintenance. However, only the variations in water use and harvest index could be logically associated with differences in turgor maintenance. Analysis of the soil water extraction data showed that the differences in water use efficiency were due solely to differences in water use at depth while surface water losses were the same, i.e. the ratio of transpiration to soil evaporation would have been higher in low-osmoregulating genotypes. At low water deficits, no differences were observed in harvest index, though there were non-significant correlations between turgor maintenance and total water use efficiency or total water use. A similar result was obtained when the water use and yield data were related to osmoregulation measurements made in the glasshouse. It is therefore concluded that effects of turgor maintenance or osmoregulation on grain yield were primarily associated with differences in water use which were, in turn, due to differences in water extraction at soil depths between 25 and 150 cm.


1993 ◽  
Vol 44 (8) ◽  
pp. 1693 ◽  
Author(s):  
AG Condon ◽  
RA Richards ◽  
GD Farquhar

Carbon isotope discrimination (-) has been shown to be negatively correlated with water use efficiency for wheat cultivars grown in the glasshouse. In the field this negative correlation has been confirmed for peanut but it has yet to be confirmed for wheat. Indeed, several field studies on wheat have shown positive (rather than negative) relationships between dry matter production and -. The aim of this study was to determine the relationship between - and water use efficiency for wheat grown in a dryland environment characterized by winterlspring-dominant rainfall and terminal drought. Eight genotypes chosen to give a range in - of c. 2.0x10-3 were grown on a red earth at Moombooldool in the Riverina region of New South Wales. Water use and above-ground dry matter (DM) were measured over the course of the season. Water use was partitioned into transpiration and soil evaporation and values of crop water use efficiency (WET) and transpiration efficiency ( WT) calculated. To account for the effect on WT of seasonal changes in the vapour pressure deficit of the air (D), crop coefficients (k) were derived by multiplying WT by the transpiration-weighted average daytime value of D for each genotype. During the preanthesis period, when there was little limitation of soil water supply on growth, there was a positive relationship between DM and -, as observed previously. The relationship between WET and - also had a positive (though non-significant) trend, but the relationship between k and - was negative, i.e. once the effects of variation in the ratio T/ET and seasonal changes in D were accounted for, the negative correlation between water use efficiency and - re-emerged. This apparent conflict between WET and k arose because genotypes with high - values developed their leaf area faster, with two important consequences. First, high - genotypes transpired more of their water supply during the winter when D was low and the exchange of water for CO2 more efficient. Second, transpiration made up a greater proportion of total water use by high - genotypes. The relationship between water use efficiency and - was further complicated as the crops depleted the soil water store after anthesis. During this period DM production tended to be greater in low - genotypes that had conserved soil water in the preanthesis period. However, DM production also remained high for two high - genotypes. The cause of this variation in post-anthesis growth among high - genotypes was not established.


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

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.


2021 ◽  
Author(s):  
Pablo Affortit ◽  
Branly Effa Effa ◽  
Mame Sokhatil Ndoye ◽  
Daniel Moukouanga ◽  
Nathalie Luchaire ◽  
...  

Because water availability is the most important environmental factor limiting crop production, improving water use efficiency, the amount of carbon fixed per water used, is a major target for crop improvement. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative component trait transpiration restriction under high evaporative demand, remain unknown. These traits were measured in a panel of 147 African rice Oryza glaberrima genotypes, known as potential sources of tolerance genes to biotic and abiotic stresses. Our results reveal that higher transpiration efficiency is associated with transpiration restriction in African rice. Detailed measurements in a subset of highly differentiated genotypes confirmed these associations and suggested that the root to shoot ratio played an important role in transpiration restriction. Genome wide association studies identified marker-trait associations for transpiration response to evaporative demand, transpiration efficiency and its residuals, that links to genes involved in water transport and cell wall patterning. Our data suggest that root shoot partitioning is an important component of transpiration restriction that has a positive effect on transpiration efficiency in African rice. Both traits are heritable and define targets for breeding rice with improved water use strategies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Li ◽  
Dagang Guo ◽  
Xiaodong Gao ◽  
Xining Zhao

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.


Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Maricar Aguilos ◽  
Clément Stahl ◽  
Benoit Burban ◽  
Bruno Hérault ◽  
Elodie Courtois ◽  
...  

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.


2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20–60 cm, increased water recharge by 16–21 mm, and decreased ASWS by 89–133 mm in 0–300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246–1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was < 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.


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