Soil water dynamics, herbage production and water use efficiency of three tropical grasses: Implications for use in a variable summer-dominant rainfall environment, Australia

2018 ◽  
Vol 74 (1) ◽  
pp. 141-159 ◽  
Author(s):  
Sean R. Murphy ◽  
Suzanne P. Boschma ◽  
Steven Harden
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Tropical Grasses ◽  
Use Efficiency

Soil water regimes of rotationally grazed perennial and annual forages

1999 ◽  
Vol 79 (4) ◽  
pp. 627-637 ◽  
Author(s):  
D. A. Twerdoff ◽  
D. S. Chanasyk ◽  
M. A. Naeth ◽  
V. S. Baron ◽  
E. Mapfumo
Keyword(s):  
Plant Growth ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Management Practices ◽  
Grazing Intensity ◽  
Water Dynamics ◽  
Research Station ◽  
Grazing Intensities ◽  
Use Efficiency

To maintain a sustainable agricultural system, management practices such as grazing must ensure adequate soil water for plant growth, yet minimize the risk of soil erosion. The objective of this study was to characterize the soil water regime of perennial and annual forages under three grazing intensities (heavy, medium and light). The study was conducted at the Lacombe Research Station, Alberta, on an Orthic Black Chernozem of loam to silt loam texture. The forages used were smooth bromegrass (Bromus inermis L. 'Carlton'), meadow bromegrass (Bromus riparius L. 'Paddock'), a mixture of triticale (X Triticosecale Wittmack 'Pika') and barley (Hordeum vulgare L. 'AC Lacombe') and triticale. Soil water measurements were conducted between April and October of 1994 and 1995 using a neutron scattering hydroprobe to a depth of 90 cm. Surface (0–7.5 cm) soil water was more responsive to grazing intensity than soil water accumulated to various depths. For all grazing treatments and forages, both surface soil water and accumulated soil water generally fluctuated between field capacity and wilting point during the growing season. Although plant water status was not determined, no visual permanent wilting of forages was observed during the study. Differences in evapotranspiration (ET), as determined by differences in soil water were evident among forage species but not grazing intensities, with perennials having high ET in spring and annuals having high ET in summer. Estimated values of water-use efficiency (WUE) were greater for perennials than for annuals and grazing effects on WUE were minimal. From a management perspective, grazing of annuals and perennials altered soil water dynamics but still maintained adequate soil water for plant growth. Key words: Evapotranspiration, forages, grazing intensity, water-use efficiency

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.

Modelling soil water dynamics and crop water use in a soybean-wheat rotation under chisel tillage in a sandy clay loam soil

Geoderma ◽  
2018 ◽  
Vol 327 ◽  
pp. 13-24 ◽  
Author(s):  
Mukhtar Ahmad ◽  
Debashis Chakraborty ◽  
Pramila Aggarwal ◽  
Ranjan Bhattacharyya ◽  
Ravender Singh
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Dynamics ◽  
Clay Loam ◽  
Crop Water ◽  
Soil Water Dynamics ◽  
Clay Loam Soil ◽  
Sandy Clay Loam ◽  
Crop Water Use ◽  
Loam Soil

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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