Effects of water deficits on 13C discrimination and transpiration efficiency of Eucalyptus globulus clones

1998 ◽  
Vol 25 (6) ◽  
pp. 645 ◽  
Author(s):  
Júlio Osório ◽  
M. Leonor Osório ◽  
M. Manuela Chaves ◽  
João S. Pereira
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Eucalyptus Globulus ◽  
Isotope Composition ◽  
Stomatal Closure ◽  
Stable Carbon Isotope ◽  
Leaf Tissue ◽  
Transpiration Efficiency ◽  
Soil Water Deficit ◽  
Water Deficits

Potted cuttings of three Eucalyptus globulus Labill. clones (AR3, CN44, MP11) were grown over 6 months in a greenhouse under three watering regimes: well watered (HW), moderate soil water deficit (MS) and severe soil water deficit (SS). Transpiration efficiency (W = total dry matter/water transpired) and leaf intrinsic gas exchange efficiency (A/gs = carbon assimilation rate/stomatal conductance) increased under water stress and were positively correlated with the stable carbon isotope composition of leaf tissue (δ13C). The clones did not vary significantly with respect to A/gs and W. However, statistically significant differences were detected among clones in δ13C, A and biomass. W did not differ between the MS and SS regimes, probably due to plant acclimation to increasing soil water deficits. The increase in W with soil water deficits relative to the well watered control was primarily associated with stomatal closure, but was also influenced by differences in respiratory carbon losses (?c) and variation in the leaf-to-air water vapour difference (v). Variance in ?c and v may explain partially why the two levels of soil water deficit were different in regard to δ13C but not in terms of W.

scholarly journals Adapting a Cloud-Based Irrigation Scheduler for Sugar Beets in the High Plains

2020 ◽  
Vol 36 (4) ◽  
pp. 479-488
Author(s):  
Allan A. Andales ◽  
Andrew C. Bartlett ◽  
Troy A. Bauder ◽  
Erik M. Wardle
Keyword(s):  
Sugar Beet ◽  
Soil Water ◽  
Water Deficit ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Weather Data ◽  
High Plains ◽  
Soil Water Deficit ◽  
Sugar Beets ◽  
Water Deficits

Highlights An existing sugar beet crop coefficient curve (K cr ) was modified to better represent canopy development in northeast Colorado conditions. The modified K cr curve improved the estimated soil water deficits (net irrigation requirements) calculated by the cloud-based Water Irrigation Scheduler for Efficient Application (WISE App). Feedback from sugar beet growers and agronomists helped expand WISE applicability in the northern High Plains with access to additional weather station networks and functionality to aggregate irrigation data across multiple sugar beet fields or regions. Abstract . The convergence of agrometeorological network, database, and cloud-computing technologies has enabled greater accessibility of irrigation management tools for growers. The goal of this research and outreach project was to adapt an existing cloud-based irrigation scheduler (WISE) for use by sugar beet (Beta vulgaris L.) producers in eastern Colorado and a wider area of a cooperative operating in Colorado, Nebraska, Wyoming, and Montana. Four center pivot sugar beet fields in northeast Colorado were monitored during the 2013 and 2014 growing seasons. Soil water, leaf area index (LAI), and weather data were used to estimate the soil water deficit (net irrigation requirement) and to modify a crop coefficient (Kcr) curve originally reported in the literature based on growing degree days (GDD). The average cumulative GDDs for sugar beets to mature (100% maturity) was 2,944°C·d. The localized Kcr had a peak value (Kcr,mid) occurring between 43% and 69% of maturity, which corresponded to effective full cover (LAI = 3) and start of leaf senescence, respectively. In contrast, the original Kcr curve from literature had a longer duration of Kcr,mid spanning 33% to 83% of maturity. Use of the modified Kcr curve in lieu of the original Kcr curve in WISE reduced the relative error of soil water deficits by 12% to 35%. Feedback and collaborations from representative sugar beet growers and agronomists in the Western Sugar Cooperative led to expansion of WISE weather data access in the High Plains to include sugar beet growing areas in western Nebraska, eastern and northern Wyoming, and southern Montana. Keywords: Crop coefficient, Evapotranspiration, Irrigation scheduling, Soil water balance, Soil water deficit, Sugar beets.

Water content of a red-brown earth subjected to a range of agronomic vegetation options in south-eastern Australia

2001 ◽  
Vol 52 (5) ◽  
pp. 587 ◽  
Author(s):  
D. M. Whitfield
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Deficit ◽  
Soil Water Deficit ◽  
Water Deficits ◽  
South Eastern ◽  
Eastern Australia ◽  
Ground Water Recharge ◽  
South Eastern Australia

The management of ground water recharge in south-eastern Australia relies on the formulation of agricultural practices that utilise rainfall before it moves below the root-zone. Annual cycles of soil water content were therefore measured in a red-brown earth subjected to 5 fallow-free crop sequences, to 2 crop sequences that included fallow, and to 3 pastures. Changes in soil water content induced by wheat, barley, lupin, pea, safflower, canola, and fallow were compared with those of annual pasture and 2 monocultures of the deep-rooted perennials phalaris and lucerne in 3 years of study. Mean minimum soil water content (0–1.6 m) seen in December and May was approximately 355 mm in lucerne and phalaris, 410 mm in annuals (crops and pasture), and 475 mm in fallow. Corresponding soil water deficits appropriate to lucerne, annuals, and fallow were 185, 135, and 65 mm, respectively. Lucerne and annuals both removed approximately 85 mm water from the upper 0.6 m of the soil profile. Differences arose in the subsoil below 0.6 m, where lucerne, annuals, and fallow produced soil water deficits of approximately 100, 50, and 25 mm, respectively. The difference in soil water deficit of deep-rooted perennials and annuals was therefore caused by the extra 50 mm of water extracted by lucerne and phalaris below 0.6 m in the period September–December. The dry subsoil endured through summer to promote the storage, by soil, of rainfall in winter. The data suggest that the spatial utility of an agronomic recharge control option in south-eastern Australia depends on the magnitude of the soil water deficit associated with the vegetation. The soil water deficit, relative to winter (May–August) rainfall, discriminates between areas where annuals suffice for recharge control, where lucerne and phalaris are required for recharge control, and where agronomic annuals and perennials are both conducive to high rates of drainage.

Physiological trade-offs of stomatal closure under high evaporative gradients in field grown soybean

2016 ◽  
Vol 43 (1) ◽  
pp. 40 ◽  
Author(s):  
Viviana Medina ◽  
Matthew E. Gilbert
Keyword(s):  
Stomatal Conductance ◽  
Soil Water ◽  
Water Deficit ◽  
Agricultural Research ◽  
Stomatal Closure ◽  
Photochemical Efficiency ◽  
Vapour Pressure Deficit ◽  
Soil Water Deficit ◽  
Night Time ◽  
Trade Offs

Limited rainfall is the main constraint to agriculture, making agricultural research to understand plant behaviour that leads to avoidance of soil water deficit a matter of priority. One focus has screened for crop varieties that decrease stomatal conductance under high vapour pressure deficit (VPD), a proxy for the leaf evaporative gradient. However, the link between stomatal closure and physiological consequences in field environments is not yet clear. A field experiment on soybeans demonstrated that considerable variation in leaf temperature relative to air temperature occurred, leading to evaporative gradients differing substantially from VPD. Thus, transpiration is decreased by stomatal closure at high VPD, but to compensate, transpiration is somewhat increased due to higher leaf temperatures. Soil water deficit led to lower stomatal conductance, particularly under low evaporative conditions, not just under hot conditions. Non-stomatal photosynthetic limitations were observed due to combined occurrence of stomatal closure and high temperature under high VPD. Although leaves reached temperatures higher than the threshold for a decrease in maximum photochemical efficiency, and displayed non-stomatal photosynthetic limitations, no photoinhibition or damage was observed by night-time. The results demonstrate that more understanding of physiological strategies for achieving altered water use is needed to avoid trade-offs and heat stress.

scholarly journals Varietal responses to soil water deficit: first results from a common-garden vineyard near Bordeaux France

2018 ◽  
Vol 50 ◽  
pp. 01043 ◽  
Author(s):  
Mark Gowdy ◽  
Agnès Destrac-Irvine ◽  
Martina Haines ◽  
Gregory Gambetta ◽  
Philippe Pieri ◽  
...  
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Water Status ◽  
Stomatal Closure ◽  
Common Garden ◽  
Soil Water Deficit ◽  
Water Deficits ◽  
Water Potential Measurements

In wine producing regions around the world, climate change has the potential to decrease the frequency and amount of precipitation and increase average and extreme temperatures. This will both lower soil water availability and increase evaporative demand in vineyards, thereby increasing soil water deficits and associated vine stress. Grapevines control their water status by regulating stomatal closure and other changes to internal plant hydraulics. These responses are complex and have not been clearly characterized across a wide range of different Vitis vinifera varieties. Understanding how vine water status responds to changes in soil water deficits and other variables will help growers modify vineyard design and management practices to meet their quality and yield objectives. Carbon isotope discrimination measurements of certain plant tissues have been shown to provide effective characterization of stomatal closure, while water potential measurements provide a well-proven measure of overall vine water status. Using replicated data collected from an experimental common-garden vineyard at the Institut des Sciences de la Vigne et du Vin (ISVV) near Bordeaux, France, this project will analyze the effects on carbon isotope discrimination across 39 varieties and water potential across eight varieties against estimates of soil water deficits made using a water balance model running on local meteorology and considering the phenology of each variety. Similar to the literature, preliminary analysis finds as soil water deficit increases, carbon isotope data suggests greater stomatal closure and water potential measurements indicate greater vine stress. For both parameters, analysis will be performed to distinguish any difference in these responses between varieties.

Relation of Soil Water Deficit, Involved by Precipitation and Corn Yield on Vinkovci Area (Eastern Croatia)

1998 ◽  
Vol 26 (3) ◽  
pp. 289-296
Author(s):  
M. Jurišić ◽  
Ž. Vidaček ◽  
Ž. Bukvić ◽  
D. Brkić ◽  
R. Emert
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Corn Yield ◽  
Soil Water Deficit

Water use by winter wheat as affected by soil management

1984 ◽  
Vol 103 (1) ◽  
pp. 189-199 ◽  
Author(s):  
M. J. Goss ◽  
K. R. Howse ◽  
Judith M. Vaughan-Williams ◽  
M. A. Ward ◽  
W. Jenkins
Keyword(s):  
Winter Wheat ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Management Practices ◽  
Soil Management ◽  
Maximum Depth ◽  
Water Extraction ◽  
Soil Water Deficit ◽  
Potential Yield

SummaryIn each of the years from September 1977 to July 1982 winter wheat was grown on one or more of three clay soil sites (clay content 35–55%) in Oxfordshire where the climate is close to the average for the area of England growing winter cereals.The effects on crop water use of different soil management practices, including ploughing, direct drilling and subsoil drainage, are compared. Cultivation treatment had little effect on the maximum depth of water extraction, which on average in these clay soils was 1·54 m below the soil surface. Maximum soil water deficit was also little affected by cultivation; the maximum recorded value was 186±7·6 mm. Subsoil drainage increased the maximum depth of water extraction by approximately 15 cm and the maximum soil water deficit by about 17 mm.Generally soil management had little effect on either total water use by the crop which was found to be close to the potential evaporation estimated by the method of Penman, or water use efficiency which for these crops was about 52 kg/ha par mm water used.Results are discussed in relation to limitations to potential yield.

The Effect of Dry Pegging Zone Soil on Pod Formation of Florunner Peanut1

1997 ◽  
Vol 24 (1) ◽  
pp. 19-24 ◽  
Author(s):  
P. J. Sexton ◽  
J. M. Bennett ◽  
K. J. Boote
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Deficit ◽  
Growth Rates ◽  
Root Zone ◽  
Soil Water Deficit ◽  
Seed Growth ◽  
Pod Development

Abstract Peanut (Arachis hypogaea L.) fruit growth is sensitive to surface soil (0-5 cm) conditions due to its subterranean fruiting habit. This study was conducted to determine the effect of soil water content in the pegging zone (0-5 cm) on peanut pod growth rate and development. A pegging-pan-root-tube apparatus was used to separately control soil water content in the pegging and root zone for greenhouse trials. A field study also was conducted using portable rainout shelters to create a soil water deficit. Pod phenology, pod and seed growth rates, and final pod and seed dry weights were determined. In greenhouse studies, dry pegging zone soil delayed pod and seed development. In the field, soil water deficits in the pegging and root zone decreased pod and seed growth rates by approximately 30% and decreased weight per seed from 563 to 428 mg. Pegs initiating growth during drought stress demonstrated an ability to suspend development during the period of soil water deficit and to re-initiate pod development after the drought stress was relieved.

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