Correlation of soil water content determination by neutron backscatter and almond tree stem water potential for microirrigation scheduling in almonds

2010 ◽  
Author(s):  
Blake L Sanden ◽  
Ken A Shackel ◽  
Patrick H Brown
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Stem Water Potential ◽  
Almond Tree ◽  
Content Determination ◽  
Stem Water ◽  
Tree Stem

scholarly journals Estimating Midday Leaf and Stem Water Potentials of Mature Pecan Trees from Soil Water Content and Climatic Parameters

HortScience ◽  
2012 ◽  
Vol 47 (7) ◽  
pp. 907-916 ◽  
Author(s):  
Sanjit K. Deb ◽  
Manoj K. Shukla ◽  
John G. Mexal
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Conditions ◽  
Silty Clay ◽  
Stem Water Potential ◽  
Stem Water ◽  
Two Parameter

Diurnal and temporal patterns of stem water potential (ψstem) and leaf water potential (ψleaf) were determined during June to Sept. 2010 and 2011 at lower (2.5 m tree height), mid- (4.6 m), and upper (7.6 m) canopy positions for two flood-irrigated, mature pecan [Carya illinoinensis (Wangenh.) K. Koch] orchards near Las Cruces, NM. Diurnal measurements of ψstem and ψleaf at three canopy heights were correlated under both dry and wet soil conditions. However, although soil water contents at Site 2 (silty clay loam texture) remained higher compared with Site 1 (sandy loam), ψstem and ψleaf values, particularly under dry soil conditions at Site 2, were consistently lower, showing the effect of clayey soil texture on pecan water stress. Diurnal patterns of ψstem and ψleaf indicated that measurements of ψstem and ψleaf should be made close to early afternoon (between 1400 and 1500 hr Mountain Standard Time) to evaluate mature pecan water stress, which also corresponded to maximum climatic stress conditions. Midday ψstem and ψleaf measured at three canopy heights over several irrigation cycles during the 2010 season were correlated with one another, midday soil water content at different depths, and atmospheric vapor pressure deficit (VPD). Multiple regression analysis [between midday ψstem or ψleaf and midday θavg (soil water content at 0 to 40 cm), air temperature (Tmd), and relative humidity (RHmd)] during the 2010 season revealed that two-parameter regression models [ψstem or ψleaf = f (midday θavg and Tmd)] were the most significant for the interpretation of midday ψstem or ψleaf at both sites. Using the two-parameter model, predictions of ψstem and ψleaf measured on the both shaded and sunlit sides of trees at three canopy heights for 2011 showed good agreement between measured and predicted ψstem and ψleaf (R2 ranged from 0.70 to 0.98). Two-parameter models derived in an earlier study generally underpredicted ψstem both in 2010 and 2011, which further supported the importance of the time of midday ψstem and ψleaf measurements suggested in this study.

scholarly journals How Do Novel M-Rootstock (Vitis Spp.) Genotypes Cope with Drought?

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1385
Author(s):  
Davide Bianchi ◽  
Leila Caramanico ◽  
Daniele Grossi ◽  
Lucio Brancadoro ◽  
Gabriella De Lorenzis
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Growth Cycle ◽  
Arid Environments ◽  
Stem Water Potential ◽  
Abscisic Acid Biosynthesis ◽  
Stem Water ◽  
Vitis Spp

Most of the vineyards around the world are in areas characterized by seasonal drought, where water deficits and high temperatures represent severe constraints on the regular grapevine growth cycle. Although grapevines are well adapted to arid and semi-arid environments, water stress can cause physiological changes, from mild to irreversible. Screening of available Vitis spp. genetic diversity for new rootstock breeding programs has been proposed as a way for which new viticulture challenges may be faced. In 2014, novel genotypes (M-rootstocks) were released from the University of Milan. In this work, the behavior of M1, M3 and M4 in response to decreasing water availabilities (80%, 50% and 20% soil water content, SWC) was investigated at the physiological and gene expression levels, evaluating gas exchange, stem water potential and transcript abundances of key genes related to ABA (abscisic acid) biosynthesis (VvZEP, VvNCED1 and VvNCED2) and signaling (VvPP2C4, VvSnRK2.6 and VvABF2), and comparing them to those of cuttings of nine commercial rootstocks widely used in viticulture. M-rootstocks showed a change at physiological levels in severe water-stressed conditions (20% soil water content, SWC), reducing the stomatal conductance and stem water potential, but maintaining high photosynthetic activity. Water use efficiency was high in water-limiting conditions. The transcriptional changes were observed at 50% SWC, with an increment of transcripts of VvNCED1 and VvNCED2 genes. M-rootstocks showed similar behavior to 1103P and 110R rootstocks, two highly tolerant commercial genotypes. These rootstocks adopted a tolerant strategy to face water-stressed conditions.

scholarly journals The Effect of Irrigation Rate on the Water Relations of Young Citrus Trees in High-Density Planting

2021 ◽  
Vol 13 (4) ◽  
pp. 1759
Author(s):  
Said A. Hamido ◽  
Kelly T. Morgan
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Salinity ◽  
Planting Density ◽  
Stem Water Potential ◽  
Irrigation Rate ◽  
Biological Stress ◽  
Stem Water ◽  
Water Contents ◽  
Soil Water Contents

The availability and proper irrigation scheduling of water are some of the most significant limitations on citrus production in Florida. The proper volume of citrus water demand is vital in evaluating sustainable irrigation approaches. The current study aims to determine the amount of irrigation required to grow citrus trees at higher planting densities without detrimental impacts on trees’ water relation parameters. The study was conducted between November 2017 and September 2020 on young sweet orange (Citrus sinensis) trees budded on the ‘US-897’ (Cleopatra mandarin x Flying Dragon trifoliate orange) citrus rootstock transplanted in sandy soil at the Southwest Florida Research and Education Center (SWFREC) demonstration grove, near Immokalee, Florida. The experiment contained six planting densities, including 447, 598, and 745 trees per ha replicated four times, and 512, 717, and 897 trees per ha replicated six times. Each density treatment was irrigated at 62% or 100% during the first 15 months between 2017 and 2019 or one of the four irrigation rates (26.5, 40.5, 53, or 81%) based on the calculated crop water supplied (ETc) during the last 17 months of 2019–2020. Tree water relations, including soil moisture, stem water potential, and water supplied, were collected periodically. In addition, soil salinity was determined. During the first year (2018), a higher irrigation rate (100% ETc) represented higher soil water contents; however, the soil water content for the lower irrigation rate (62% ETc) did not represent biological stress. One emitter per tree regardless of planting density supported stem water potential (Ψstem) values between −0.80 and −0.79 MPa for lower and full irrigation rates, respectively. However, when treatments were adjusted from April 2019 through September 2020, the results substantially changed. The higher irrigation rate (81% ETc) represented higher soil water contents during the remainder of the study, the lower irrigation rate (26.5% ETc) represents biological stress as a result of stem water potential (Ψstem) values between −1.05 and −0.91 MPa for lower and higher irrigation rates, respectively. Besides this, increasing the irrigation rate from 26.5% to 81%ETc decreased the soil salinity by 33%. Although increasing the planting density from 717 to 897 trees per hectare reduced the water supplied on average by 37% when one irrigation emitter was used to irrigate two trees instead of one, applying an 81% ETc irrigation rate in citrus is more efficient and could be managed in commercial groves.

scholarly journals Unexpected relationships between δ13C and wine grape performance in organic farming

OENO One ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 269 ◽  
Author(s):  
Edoardo Antonio Costantino Costantini ◽  
Alessandro Agnelli ◽  
Pierluigi Bucelli ◽  
Aldo Ciambotti ◽  
Valentina Dell’Oro ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Soil Water ◽  
Organic Farming ◽  
Water Availability ◽  
Stress Conditions ◽  
Soil Water Availability ◽  
Wine Grape ◽  
Stem Water Potential ◽  
Stem Water

<p style="text-align: justify;"><strong>Aim</strong>: To evaluate the relationship between carbon isotope ratio (δ<sup>13</sup>C) and wine grape viticultural and oenological performance in organic farming.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The study was carried out for four years in the Chianti Classico wine production district (Central Italy), on five non irrigated vineyards conducted in organic farming. The reference variety was Sangiovese. Eleven sites were chosen for vine monitoring and grape sampling. The performance parameters were alcohol and must sugar content, sugar accumulation rate, mean berry weight, and extractable polyphenols. δ<sup>13</sup>C, stem water potential, and soil water availability were also monitored. Finally, soil nitrogen as well as yeast available nitrogen in the must were measured. δ<sup>13</sup>C was directly related to stem water potential and soil water deficit, and indicated a range of water stress conditions from none and moderate to strong. However, its relationship with viticultural and oenological results was contrary to expectation, that is, performance linearly increased along with soil moisture. On the other hand, the worst performance was obtained where both water and nitrogen were more limiting.</p><p style="text-align: justify;"><strong>Conclusions</strong>: The unexpected relationship between δ<sup>13</sup>C and Sangiovese performance was caused by low nitrogen availability. The studied sites all had low-fertility soils with poor or very poor nitrogen content. Therefore, in the plots where soil humidity was relatively higher, nitrogen plant uptake was favoured, and Sangiovese performance improved. Macronutrient being the main limiting factor, the performance was not lower in the plots where soil water availability was relatively larger. Therefore, the best viticultural result was obtained with no water stress conditions, at low rather than at intermediate δ<sup>13</sup>C values.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Water nutrition is crucial for wine grape performance. δ<sup>13</sup>C is a method used to assess vine water status during the growing season and to estimate vine performance. A good performance is expected at moderate stress and intermediate δ<sup>13</sup>C values. A better knowledge of the interaction between water and nutrient scarcity is needed, as it can affect the use of δ<sup>13</sup>C to predict vine performance.</p>

scholarly journals The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire

2005 ◽  
Vol 9 (6) ◽  
pp. 596-606 ◽  
Author(s):  
J. Roberts ◽  
P. Rosier
Keyword(s):  
Energy Balance ◽  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Water Potential ◽  
Eddy Correlation ◽  
Seasonal Differences ◽  
Water Potential Measurements ◽  
Shallow Soils

Abstract. The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood) and pasture (Bridgets Farm), growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration) as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.

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