Variation Characteristics of Water Content in Two Typical Eremophytes under Drought Stress in the Drift Desert Hinterland

To reveal the relationship between chlorophyll fluorescence characteristics of desert plants and soil moisture in the hinterland of the Taklimakan Desert in south Xinjiang of China, Haloxylon ammodendron and Nitraria sibirica were selected and the chlorophyll fluorescence parameters under drought stress was determined. The results were shown that: (1) The maximum light quantum yield Fv/Fm value decreased with the decline of soil moisture content. (2) Fv/Fm values of Haloxylon ammodendron and Nitraria sibirica had changed significantly; when the Fv/Fm value was significantly lower than the control value, the degree of water stress would intensify. (3) The lower limits of soil moisture contents were suitable for the growth of Haloxylon ammodendron and Nitraria sibirica were 2.50% and 3.00%, respectively.

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Growth and physiological response of two biomass sorghum (Sorghum bicolor (L.) Moench) genotypes bred for different environments, to contrasting levels of soil moisture

Italian Journal of Agronomy ◽

10.4081/ija.2015.673 ◽

2015 ◽

Vol 10 (4) ◽

pp. 208 ◽

Cited By ~ 2

Author(s):

Lorenzo Barbanti ◽

Ahmad Sher ◽

Giuseppe Di Girolamo ◽

Elio Cirillo ◽

Muhammad Ansar

Keyword(s):

Soil Moisture ◽

Stomatal Conductance ◽

Water Potential ◽

Water Content ◽

Aboveground Biomass ◽

Relative Water Content ◽

Physiological Response ◽

Field Capacity ◽

Biomass Sorghum ◽

Relative Water

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (Sorghum bicolor (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, i.e., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.

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Soil water retention curves for the major soil types of the Kruger National Park

Koedoe ◽

10.4102/koedoe.v56i1.1228 ◽

2014 ◽

Vol 56 (1) ◽

Cited By ~ 6

Author(s):

Robert Buitenwerf ◽

Andrew Kulmatiski ◽

Steven I. Higgins

Keyword(s):

Soil Moisture ◽

Water Potential ◽

Water Content ◽

Carbon Cycling ◽

Soil Water ◽

National Park ◽

Soil Water Potential ◽

Kruger National Park ◽

Soil Types ◽

Soil Moisture Retention

Soil water potential is crucial to plant transpiration and thus to carbon cycling and biosphere–atmosphere interactions, yet it is difficult to measure in the field. Volumetric and gravimetric water contents are easy and cheap to measure in the field, but can be a poor proxy of plant-available water. Soil water content can be transformed to water potential using soil moisture retention curves. We provide empirically derived soil moisture retention curves for seven soil types in the Kruger National Park, South Africa. Site-specific curves produced excellent estimates of soil water potential from soil water content values. Curves from soils derived from the same geological substrate were similar, potentially allowing for the use of one curve for basalt soils and another for granite soils. It is anticipated that this dataset will help hydrologists and ecophysiologists understand water dynamics, carbon cycling and biosphere–atmosphere interactions under current and changing climatic conditions in the region.

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Soil Moisture Sensor Test with Mississippi Delta Soils

Transactions of the ASABE ◽

10.13031/trans.12886 ◽

2019 ◽

Vol 62 (2) ◽

pp. 363-370

Author(s):

Ruixiu Sui ◽

Horace C. Pringle ◽

Edward M. Barnes

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Water Potential ◽

Water Content ◽

Soil Water ◽

Measurement Accuracy ◽

Mississippi Delta ◽

Soil Water Potential ◽

Gravimetric Method ◽

Irrigation Scheduling

Abstract. One of the methods for irrigation scheduling is to use sensors to measure the soil moisture level in the plant root zone and apply water if there is a water shortage for the plants. The measurement accuracy and reliability of the soil moisture sensors are critical for sensor-based irrigation management. This study evaluated the measurement accuracy and repeatability of the EC-5 and 5TM soil volumetric water content (SVWC) sensors, the MPS-2 and 200SS soil water potential (SWP) sensors, and the 200TS soil temperature sensor. Six 183 cm × 183 cm × 71 cm wooden compartments were built inside a greenhouse, and each compartment was filled with one type of soil from the Mississippi Delta. A total of 66 sensors with 18 data loggers were installed in the soil compartments to measure SVWC, SWP, and soil temperature. Soil samples were periodically collected from the compartments to determine SVWC using the gravimetric method. SVWC measured by the sensors was compared with that determined by the gravimetric method. The SVWC readings from the sensors had a linear regression relationship with the gravimetric SVWC (r2 = 0.82). This relationship was used to calibrate the sensor readings. The SVWC and SWP sensors could detect the general trend of soil moisture changes. However, their measurements varied significantly among the sensors. To obtain accurate absolute soil moisture measurements, the sensors require individual and soil-specific calibration. The 5TM, MPS-2, and 200TS sensors performed well in soil temperature measurement tests. Individual temperature readings from these sensors were very close to the mean of all sensor readings. Keywords: Irrigation, Sensors, Soil types, Soil water content, Soil water potential.

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Online appendix 2:Soil water retention curves for the major soil types of the Kruger National Park

Koedoe ◽

10.4102/koedoe.v56i1.1228-2 ◽

2014 ◽

Vol 56 (1) ◽

Author(s):

Robert Buitenwerf ◽

Andrew Kulmatiski ◽

Steven I. Higgins

Keyword(s):

Soil Moisture ◽

Water Potential ◽

Water Content ◽

Carbon Cycling ◽

Soil Water ◽

National Park ◽

Soil Water Potential ◽

Kruger National Park ◽

Soil Types ◽

Soil Moisture Retention

Soil water potential is crucial to plant transpiration and thus to carbon cycling and biosphere–atmosphere interactions, yet it is difficult to measure in the field. Volumetric and gravimetric water contents are easy and cheap to measure in the field, but can be a poor proxy of plant-available water. Soil water content can be transformed to water potential using soil moisture retention curves. We provide empirically derived soil moisture retention curves for seven soil types in the Kruger National Park, South Africa. Site-specific curves produced excellent estimates of soil water potential from soil water content values. Curves from soils derived from the same geological substrate were similar, potentially allowing for the use of one curve for basalt soils and another for granite soils. It is anticipated that this dataset will help hydrologists and ecophysiologists understand water dynamics, carbon cycling and biosphere–atmosphere interactions under current and changing climatic conditions in the region.

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Online appendix 1: Soil water retention curves for the major soil types of the Kruger National Park

Koedoe ◽

10.4102/koedoe.v56i1.1228-1 ◽

2014 ◽

Vol 56 (1) ◽

Author(s):

Robert Buitenwerf ◽

Andrew Kulmatiski ◽

Steven I. Higgins

Keyword(s):

Soil Moisture ◽

Water Potential ◽

Water Content ◽

Carbon Cycling ◽

Soil Water ◽

National Park ◽

Soil Water Potential ◽

Kruger National Park ◽

Soil Types ◽

Soil Moisture Retention

Soil water potential is crucial to plant transpiration and thus to carbon cycling and biosphere–atmosphere interactions, yet it is difficult to measure in the field. Volumetric and gravimetric water contents are easy and cheap to measure in the field, but can be a poor proxy of plant-available water. Soil water content can be transformed to water potential using soil moisture retention curves. We provide empirically derived soil moisture retention curves for seven soil types in the Kruger National Park, South Africa. Site-specific curves produced excellent estimates of soil water potential from soil water content values. Curves from soils derived from the same geological substrate were similar, potentially allowing for the use of one curve for basalt soils and another for granite soils. It is anticipated that this dataset will help hydrologists and ecophysiologists understand water dynamics, carbon cycling and biosphere–atmosphere interactions under current and changing climatic conditions in the region.

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Drought stress tolerance of two wheat genotypes

Soil and Water Research ◽

10.17221/10/2008-swr ◽

2008 ◽

Vol 3 (Special Issue No. 1) ◽

pp. S95-S104 ◽

Cited By ~ 3

Author(s):

A. Lukács ◽

G. Pártay ◽

T. Németh ◽

S. Csorba ◽

C. Farkas

Keyword(s):

Soil Moisture ◽

Drought Stress ◽

Water Balance ◽

Water Content ◽

Stress Tolerance ◽

Soil Water ◽

Soil Water Content ◽

Soil Columns ◽

Undisturbed Soil ◽

Wheat Genotypes

Biotic and abiotic stress effects can limit the productivity of plants to great extent. In Hungary, drought is one of the most important constrains of biomass production, even at the present climatic conditions. The climate change scenarios, developed for the Carpathian basin for the nearest future predict further decrease in surface water resources. Consequently, it is essential to develop drought stress tolerant wheat genotypes to ensure sustainable and productive wheat production under changed climate conditions. The aim of the present study was to compare the stress tolerance of two winter wheat genotypes at two different scales. Soil water regime and development of plants, grown in a pot experiment and in large undisturbed soil columns were evaluated. The pot experiments were carried out in a climatic room in three replicates. GK Élet wheat genotype was planted in six, and Mv Emese in other six pots. Two pots were left without plant for evaporation studies. Based on the mass of the soil columns without plant the evaporation from the bare soil surface was calculated in order to distinguish the evaporation and the transpiration with appropriate precision. A complex stress diagnosis system was developed to monitor the water balance elements. ECH2O type capacitive soil moisture probes were installed in each of the pots to perform soil water content measurements four times a day. The irrigation demand was determined according to the hydrolimits, derived from soil hydrophysical properties. In case of both genotypes three plants were provided with the optimum water supply, while the other three ones were drought-stressed. In the undisturbed soil columns, the same wheat genotypes were sawn in one replicate. Similar watering strategy was applied. TDR soil moisture probes were installed in the soil at various depths to monitor changes in soil water content. In order to study the drought stress reaction of the wheat plants, microsensors of 1.6 mm diameter were implanted into the stems and connected to a quadrupole mass spectrometer for gas analysis. The stress status was indicated in the plants grown on partly non-irrigated soil columns by the lower CO2 level at both genotypes. It was concluded that the developed stress diagnosis system could be used for soil water balance elements calculations. This enables more precise estimation of plant water consumption in order to evaluate the drought sensitivity of different wheat genotypes.

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Quantifying how plants with different species-specific water-use strategies cope with the same drought-prone hydro-ecological conditions

10.5194/egusphere-egu2020-9364 ◽

2020 ◽

Author(s):

Deepanshu Khare ◽

Gernot Bodner ◽

Mathieu Javaux ◽

Jan Vanderborght ◽

Daniel Leitner ◽

...

Keyword(s):

Soil Moisture ◽

Drought Stress ◽

Water Potential ◽

Water Uptake ◽

Hydraulic Properties ◽

Root Water Uptake ◽

Leaf Water ◽

Plant Water ◽

Soil Hydraulic Properties ◽

Stomatal Control

Plant transpiration and root water uptake are dependent on multiple traits that interact with site soil characteristics and environmental factors such as radiation, atmospheric temperature, relative humidity, and soil-moisture content. Models of root architecture and functions are increasingly employed to simulate root-soil interactions. Root water uptake is thereby affected by the root hydraulic architecture, soil moisture conditions, soil hydraulic properties, and the transpiration demand as controlled by atmospheric conditions. Stomatal conductance plays a vital role in regulating transpiration in plants. We performed simulations of plant water uptake for plants having different mechanisms to control transpiration, spanned by isohydric/anisohydric spectrum. Isohydric plants follow the strategy to close their stomata in order to maintain the leaf water potential at a constant level, while anisohydric plants leave their stomata open when leaf water potentials fall due to drought stress. Modelling the stomatal regulation effectively will result in a more reliable model that will regulate the excessive loss of water. We implemented hydraulic and chemical stomatal control of root water uptake following the current approach where stomatal control is regulated by simulated water potential and/or chemical signal concentration. In order to maintain water uptake from dry soil, low plant water potentials are required, which may lead to reversible or permanent cavitation. We parameterise our model with field data, including climate data and soil hydraulic properties under different tillage conditions. This helps us to understand the behaviour of different crops under drought conditions and predict at which growing stage the stress hits the plant. We conducted the simulations for different scenarios to study the effect of hydraulic and chemical regulation on root system performance under drought stress.

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Improvement of drought tolerance in white clover (Trifolium repens) by transgenic expression of a transcription factor gene WXP1

Functional Plant Biology ◽

10.1071/fp09177 ◽

2010 ◽

Vol 37 (2) ◽

pp. 157 ◽

Cited By ~ 15

Author(s):

Qingzhen Jiang ◽

Ji-Yi Zhang ◽

Xiulin Guo ◽

Mohamed Bedair ◽

Lloyd Sumner ◽

...

Keyword(s):

Transcription Factor ◽

Drought Stress ◽

Water Potential ◽

Water Content ◽

White Clover ◽

Trifolium Repens ◽

Relative Water Content ◽

Transcription Factor Gene ◽

Factor Gene ◽

Relative Water

White clover (Trifolium repens L.) is an important pasture legume in many regions of the world. A commercial cultivar of white clover (cv. Patriot) was transformed with a Medicago truncatula L. transcription factor gene, WXP1, and a reporter gene, β-glucuronidase (GUS). The WXP1 gene and the GUS gene were placed under control of the Arabidopsis CER6 promoter. GUS staining and cross-section analysis revealed the CER6 promoter directed constitutive expression in leaves and epidermis preferential expression in petioles of white clover. Independent transgenic WXP1 lines, empty vector and wild-type controls were subjected to drought stress treatment. The plants were characterised by measuring several physiological parameters including gas exchange, chlorophyll fluorescence, relative water content and leaf water potential. The WXP1 transgenic lines had higher net photosynthetic rates, higher efficiency of PSII, higher relative water content and leaf water potential under drought-stressed conditions. Consistent with the results from physiological analyses, the transgenic white clover plants carrying WXP1 showed improved tolerance to drought stress.

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