scholarly journals Assessment of Different Water Use Efficiency Calculations for Dominant Forage Crops in the Great Lakes Basin

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 739
Author(s):  
Kevin De Haan ◽  
Myroslava Khomik ◽  
Adam Green ◽  
Warren Helgason ◽  
Merrin L. Macrae ◽  
...  
Keyword(s):  
Plant Physiology ◽  
Water Use Efficiency ◽  
Water Use ◽  
Carbon Assimilation ◽  
Farming Practices ◽  
Great Lakes Basin ◽  
Forage Crops ◽  
C3 Plant ◽  
Use Efficiency ◽  
Input Variables

Water use efficiency (WUE) can be calculated using a range of methods differing in carbon uptake and water use variable selection. Consequently, inconsistencies arise between WUE calculations due to complex physical and physiological interactions. The purpose of this study was to quantify and compare WUE estimates (harvest or flux-based) for alfalfa (C3 plant) and maize (C4 plant) and determine effects of input variables, plant physiology and farming practices on estimates. Four WUE calculations were investigated: two “harvest-based” methods, using above ground carbon content and either precipitation or evapotranspiration (ET), and two “flux-based” methods, using gross primary productivity (GPP) and either ET or transpiration. WUE estimates differed based on method used at both half-hourly and seasonal scales. Input variables used in calculations affected WUE estimates, and plant physiology led to different responses in carbon assimilation and water use variables. WUE estimates were also impacted by different plant physiological responses and processing methods, even when the same carbon assimilation and water use variables were considered. This study highlights a need to develop a metric of measuring cropland carbon-water coupling that accounts for all water use components, plant carbon responses, and biomass production.

scholarly journals Carbon–water flux coupling under progressive drought

2019 ◽  
Vol 16 (13) ◽  
pp. 2557-2572 ◽  
Author(s):  
Sven Boese ◽  
Martin Jung ◽  
Nuno Carvalhais ◽  
Adriaan J. Teuling ◽  
Markus Reichstein
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Availability ◽  
Carbon Assimilation ◽  
Soil Water Availability ◽  
Natural Experiments ◽  
Water Limitation ◽  
Dry Down ◽  
Use Efficiency

Abstract. Water-use efficiency (WUE), defined as the ratio of carbon assimilation over evapotranspiration (ET), is a key metric to assess ecosystem functioning in response to environmental conditions. It remains unclear which factors control this ratio during periods of extended water limitation. Here, we used dry-down events occurring at eddy-covariance flux tower sites in the FLUXNET database as natural experiments to assess if and how decreasing soil-water availability modifies WUE at ecosystem scale. WUE models were evaluated by their performance to predict ET from both the gross primary productivity (GPP), which characterizes carbon assimilation at ecosystem scale, and environmental variables. We first compared two water-use efficiency models: the first was based on the concept of a constant underlying water-use efficiency, and the second augmented the first with a previously detected direct influence of radiation on transpiration. Both models predicting ET strictly from atmospheric covariates failed to reproduce observed ET dynamics for these periods, as they did not explicitly account for the effect of soil-water limitation. We demonstrate that an ET-attenuating soil-water-availability factor in junction with the additional radiation term was necessary to accurately predict ET flux magnitudes and dry-down lengths of these water-limited periods. In an analysis of the attenuation of ET for the 31 included FLUXNET sites, up to 50 % of the observed decline in ET was due to the soil-water-availability effect we identified in this study. We conclude by noting that the rates of ET decline differ significantly between sites with different vegetation and climate types and discuss the dependency of this rate on the variability of seasonal dryness.

scholarly journals Water-Use Efficiency of Forage Crops in the Southeastern United States

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1377
Author(s):  
Christine H. Gelley ◽  
Amanda J. Ashworth ◽  
Patrick D. Keyser ◽  
Renata L. G. Nave ◽  
Justin D. Rhinehart
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Production Efficiency ◽  
Growth Parameters ◽  
Standardized Precipitation Index ◽  
Big Bluestem ◽  
Forage Crops ◽  
Eastern Gamagrass ◽  
Use Efficiency ◽  
Sorghum Sudangrass

Preparing agricultural producers to cope with volatile weather changes, specifically drought, requires a better understanding of forage water-use efficiency (WUE) potentials. Options to improve farm resiliency to drought may include the use of C4 annual and perennial forages, which have greater production efficiency during drought than commonly used C3 forages. Our objective was to measure WUE through real-time gas exchange measurements of photosynthesis and transpiration in (1) a greenhouse study and (2) under field-grazing conditions. Growth parameters, instantaneous water use efficiency (iWUE), and mass-based WUE (mWUE) data were collected under greenhouse conditions in Study 1 for the following species: crabgrass (Digitaria sanguinalis cv. ‘Red River’), switchgrass (Panicum virgatum cv. ‘Alamo’), big bluestem (Andropogon gerardii cv. ‘OZ-70’), indiangrass (Sorghastum nutans cv. ‘Rumsey’), eastern gamagrass (Tripsacum dactyloides cv. ‘Pete’), bermudagrass (Cynodon dactylon cv. ‘Vaughn’s #1’), sorghum-sudangrass (Sorghum bicolor (L.) × Sorghum sudanese (P.) cv. ‘Greengrazer’), and tall fescue (Schedonorus arundinaceus (Schreb.) Dumort). Study 2 occurred from 2014 to 2016, and evaluated iWUE of crabgrass, switchgrass, bermudagrass, eastern gamagrass, and a big bluestem/indiangrass mix under field conditions. Overall, in situ iWUE of crabgrass, switchgrass, eastern gamagrass, and bermudagrass did not differ, while iWUE of the big bluestem/indiangrass was less than switchgrass and crabgrass, an advantage for these species if the standardized precipitation index drops below zero. Bermudagrass, switchgrass, sorghum-sudangrass, pearl millet, and indiangrass had comparable mWUE values under greenhouse-simulated drought. These results will aid in the development of forage species recommendations for mitigating drought and improving resiliency.

Comparative forage yield, water use, and water use efficiency of alfalfa, crested wheatgrass and spring wheat in a semiarid climate in southern Saskatchewan

2005 ◽  
Vol 85 (4) ◽  
pp. 877-888 ◽  
Author(s):  
Paul G. Jefferson ◽  
Herb W. Cutforth
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Soil Water ◽  
Water Use ◽  
Spring Wheat ◽  
Forage Yield ◽  
Forage Crops ◽  
Crested Wheatgrass ◽  
Use Efficiency

Crested wheatgrass (Agropyron cristatum L. Gaertn.) and alfalfa (Medicago sativa L.) are introduced forage species used for hay and grazing by cattle across western Canada. These species are well adapted to the semiarid region but their long-term responses to water stress have not been previously compared. Two alfalfa cultivars with contrasting root morphology (tap-rooted vs. creeping-rooted) and two crested wheatgrass (CWG) cultivars with different ploidy level (diploid vs. tetraploid) were compared with continuously cropped spring wheat (Triticum aestivum L.) for 6 yr at a semiarid location in western Canada. Soil water depletion, forage yield, water use efficiency, leaf water potential, osmotic potential and turgor were compared. There were no consistent differences between cultivars within alfalfa or CWG for variables measured. However, these two species exhibit different water stress response strategies. Leaf water potential of CWG was lower during midday stress period than that of alfalfa or wheat. Alfalfa apparently had greater capacity to osmotically adjust to avoid midday water stress and maintain higher turgor. Soil water use patterns changed as the stands aged. In the initial years of the trial, forage crops used soil water from upper layers of the profile. In later years, soil water was depleted down to 3 m by alfalfa and to 2 m by crested wheatgrass. Alfalfa was able to deplete soil water to lower concentrations than crested wheatgrass or wheat. Soil water depletion by wheat during the non-active growth season (after harvest to fall freeze-up) was much less than for CWG or alfalfa as expected for annual vs. perennial crops. As a result, more soil water was available to wheat during its active growth period. In the last 3 yr, the three species depleted all available soil water. Forage yield responses also changed over time. In the initial 3 yr, crested wheatgrass yielded as much as or more than alfalfa. For the last 3 yr of the experiment, alfalfa yielded more forage than crested wheatgrass. Forage crops deplete much more soil water during periods of aboveground growth dormancy than wheat. Water use efficiency of crested wheatgrass declined with stand age compared with fertilized continuous spring wheat. Alfalfa exhibited deep soil water extraction and apparent osmotic adjustment in response to water stress while CWG exhibited tolerance of low water potential during stress. Key words: forage yield, soil water, water potential, water use, water use efficiency, drought

scholarly journals Particle Films Affect Carbon Assimilation and Yield in `Empire' Apple

2003 ◽  
Vol 128 (3) ◽  
pp. 356-362 ◽  
Author(s):  
D. Michael Glenn ◽  
Amnon Erez ◽  
Gary J. Puterka ◽  
Patricia Gundrum
Keyword(s):  
Calcium Carbonate ◽  
Water Use Efficiency ◽  
Water Use ◽  
Carbon Assimilation ◽  
Canopy Temperature ◽  
Fruit Weight ◽  
Mineral Particle ◽  
Horticultural Crops ◽  
Positive Effects ◽  
Use Efficiency

Processed-kaolin particle films (PKPFs) are used commercially in large quantities on horticultural crops to repel insects, and reduce heat stress and solar injury of fruit. Our studies determined the effect of two processed-mineral particle film materials (kaolin and calcium carbonate), on whole plant carbon assimilation, water use efficiency, yield, mean fruit weight and quality in `Empire' apple [(Malus ×sylvestris (L.) Mill var. domestica (Borkh Mansf.))] over a four-year period. The application of a PKPF reduced canopy temperature, and probably reduced environmental stress, resulting in increased mean fruit weight and red color in two of the four years of the study. Whole canopy carbon assimilation studies indicated increased carbon assimilation only under conditions of high air temperature. The PKPF sprayed leaves also had reduced water use efficiency; likely due to increased stomatal conductance associated with reduced leaf temperature. Calcium carbonate had none of the positive effects of PKPF and reflected more photosynthetically active radiation (PAR) than the PKPF.

scholarly journals Influence of Mulching on Yield and Water Use Efficiency of Perennial Forage Crops

2017 ◽  
Vol 6 (11) ◽  
pp. 792-800
Author(s):  
Himangshu Das ◽  
Champak Kumar Kundu ◽  
Asis Mukherjee ◽  
Ratneswar Poddar ◽  
Pintoo Bandopadhyay
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Forage Crops ◽  
Use Efficiency

scholarly journals Water Use, Leaf Cooling and Carbon Assimilation Efficiency of Heat Resistant Common Beans Evaluated in Western Amazonia

2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Carlos Suárez ◽  
Milan O. Urban ◽  
Amara Tatiana Contreras ◽  
Jhon Eduar Noriega ◽  
Chetan Deva ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Acid Soil ◽  
Crop Improvement ◽  
Assimilation Efficiency ◽  
Carbon Assimilation ◽  
Acid Soils ◽  
Soil Conditions ◽  
Heat Resistant ◽  
Use Efficiency

In our study, we analyzed 30years of climatological data revealing the bean production risks for Western Amazonia. Climatological profiling showed high daytime and nighttime temperatures combined with high relative humidity and low vapor pressure deficit. Our understanding of the target environment allows us to select trait combinations for reaching higher yields in Amazonian acid soils. Our research was conducted using 64 bean lines with different genetic backgrounds. In high temperatures, we identified three water use efficiency typologies in beans based on detailed data analysis on gasometric exchange. Profligate water spenders and not water conservative accessions showed leaf cooling, and effective photosynthate partitioning to seeds, and these attributes were found to be related to higher photosynthetic efficiency. Thus, water spenders and not savers were recognized as heat resistant in acid soil conditions in Western Amazonia. Genotypes such as BFS 10, SEN 52, SER 323, different SEFs (SEF 73, SEF 10, SEF 40, SEF 70), SCR 56, SMR 173, and SMN 99 presented less negative effects of heat stress on yield. These genotypes could be suitable as parental lines for improving dry seed production. The improved knowledge on water-use efficiency typologies can be used for bean crop improvement efforts as well as further studies aimed at a better understanding of the intrinsic mechanisms of heat resistance in legumes.

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