EFFECTS OF VERTICALLY HETEROGENEOUS SOIL SALINITY ON PLANT GROWTH AND WATER UPTAKE

Soil Science ◽  
1968 ◽  
Vol 106 (2) ◽  
pp. 85-93 ◽  
Author(s):  
J. SHALHEVET ◽  
L. BERNSTEIN
Keyword(s):  
Plant Growth ◽  
Water Uptake ◽  
Soil Salinity ◽  
Heterogeneous Soil

A simple numerical model to estimate water availability in saline soils

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 264 ◽  
Author(s):  
Mohammad Hossein Mohammadi ◽  
Mahnaz Khataar
Keyword(s):  
Numerical Model ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Weighting Function ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Evapotranspiration Rate

We developed a numerical model to predict soil salinity from knowledge of evapotranspiration rate, crop salt tolerance, irrigation water salinity, and soil hydraulic properties. Using the model, we introduced a new weighting function to express the limitation imposed by salinity on plant available water estimated by the integral water capacity concept. Lower and critical limits of soil water uptake by plants were also defined. We further analysed the sensitivity of model results to underlying parameters using characteristics given for corn, cowpea, and barley in the literature and two clay and sandy loam soils obtained from databases. Results showed that, between two irrigation events, soil salinity increased nonlinearly with decreasing soil water content especially when evapotranspiration and soil drainage rate were high. The salinity weighting function depended greatly on the plant sensitivity to salinity and irrigation water salinity. This research confirmed that both critical and lower limits (in terms of water content) of soil water uptake by plants increased with evapotranspiration rate and irrigation water salinity. Since the presented approach is based on a physical concept and well-known plant parameters, soil hydraulic characteristics, irrigation water salinity, and meteorological conditions, it may be useful in spatio-temporal modelling of soil water quality and quantity and prediction of crop yield.

A general approach for analytically upscaling the exact root water uptake equations despite heterogeneous soil moisture at the soil-root interface

2021 ◽  
Author(s):  
Martin Bouda ◽  
Jan Vanderborght ◽  
Mathieu Javaux
Keyword(s):  
Soil Moisture ◽  
Exact Solutions ◽  
Root System ◽  
Water Uptake ◽  
Grid Cell ◽  
Earth System ◽  
Water Flows ◽  
Heterogeneous Soil ◽  
Soil Moisture Heterogeneity ◽  
Earth System Models

<p>Recent advances in scaling up water flows on root system networks hold promise for improving predictions of water uptake at large scales. These developments are particularly timely, as persistent difficulties in getting Earth system models to accurately represent soil-root water flows, especially under drying or heterogeneous soil moisture conditions, are now a major obstacle describing the water limitation of terrestrial fluxes.</p><p>One recently developed upscaling formalism has been shown to be both free of discretisation error in flow predictions regardless of scale and with computational cost linearly diminishing with the number of soil subdomains considered. What has been missing from this approach, however, is a proven method to apply it generally – i.e. to an arbitrary root system architecture discretised on an arbitrary grid.</p><p>The work presented here demonstrates a general algorithm that can be applied to a wide range of root system architectures (the only assumption being that only one lateral root originates at one point along a parent root) discretised on a grid consisting of a series of soil layers of variable thickness, as is common in Earth system models. It is further shown theoretically that both of these restrictions can in principle be relaxed and that this approach can in principle be extended to conditions of soil moisture heterogeneity – i.e. situations where each root segment in a soil grid cell faces a different water potential at the soil-root interface.</p><p>This work represents both a practical advance bringing broad applicability to this upscaling approach and a major theoretical advance as exact solutions for water uptake under conditions of soil moisture heterogeneity within grid cells were previously unknown. While obtaining exact solutions despite heterogeneity within the grid cell requires a way of finding the overall mean soil water potential faced by the plant, this advance nevertheless points to possible directions of future research for overcoming the major hurdle of soil moisture heterogeneity.</p>

scholarly journals Salt Tolerance and Na Allocation in Sorghum bicolor under Variable Soil and Water Salinity

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 561 ◽  
Author(s):  
Roberta Calone ◽  
Rabab Sanoubar ◽  
Carla Lambertini ◽  
Maria Speranza ◽  
Livia Vittori Antisari ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Sorghum Bicolor ◽  
Soil Salinity ◽  
Ion Homeostasis ◽  
Dry Weight ◽  
Water Salinity ◽  
Selective Absorption ◽  
Salt Leaching ◽  
Sensitive Organ

Salinity is a major constraint for plant growth in world areas exposed to salinization. Sorghum bicolor (L.) Moench is a species that has received attention for biomass production in saline areas thanks to drought and salinity tolerance. To improve the knowledge in the mechanisms of salt tolerance and sodium allocation to plant organs, a pot experiment was set up. The experimental design combined three levels of soil salinity (0, 3, and 6 dS m−1) with three levels of water salinity (0, 2–4, and 4–8 dS m−1) and two water regimes: no salt leaching (No SL) and salt leaching (SL). This latter regime was carried out with the same three water salinity levels and resulted in average +81% water supply. High soil salinity associated with high water salinity (HSS-HWS) affected plant growth and final dry weight (DW) to a greater extent in No SL (−87% DW) than SL (−42% DW). Additionally, HSS-HWS determined a stronger decrease in leaf water potential and relative water content under No SL than SL. HSS-HWS with No SL resulted in a higher Na bioaccumulation from soil to plant and in translocation from roots to stem and, finally, leaves, which are the most sensitive organ. Higher water availability (SL), although determining higher salt input when associated with HWS, limited Na bioaccumulation, prevented Na translocation to leaves, and enhanced selective absorption of Ca vs. Na. At plant level, higher Na accumulation was associated with lower Ca and Mg accumulation, especially in No SL. This indicates altered ion homeostasis and cation unbalance.

Sensitivity and uncertainty analysis of the HYDRUS-1D model for root water uptake in saline soils

2018 ◽  
Vol 69 (2) ◽  
pp. 163 ◽  
Author(s):  
Wenzhi Zeng ◽  
Guoqing Lei ◽  
Yuanyuan Zha ◽  
Yuanhao Fang ◽  
Jingwei Wu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Water Uptake ◽  
Soil Salinity ◽  
Root Water Uptake ◽  
Stress Factors ◽  
Saline Soils ◽  
Growth Stages ◽  
1D Model ◽  
Maximum Root ◽  
Hydrus 1D

A variance-based global sensitivity analysis (extended Fourier amplitude sensitivity test, EFAST) was applied to the Feddes module of the HYDRUS-1D model, and the sensitivity indices including both main and total effects of actual root water uptake (RWUa) to seven Feddes parameters were quantified at different growth stages of sunflower (Helianthus annuus L.): seedling, bud, flowering and maturity. The effects of soil salinity, climate conditions, and crop root growth on parameter sensitivity were explored by analysing three precipitation frequencies and two maximum root depths across four field locations with different soil salinity levels in China’s sunflower-growing regions. Uncertainties for RWUa were evaluated at four stages with varying Feddes parameters for different field locations, precipitation frequencies and maximum root depths. We found that the water stress factor concerning ceasing root water uptake (h4), and two salt stress factors ht and Sp, indicating the salinity threshold and the slope of the curve determining the fractional decline in root water uptake per unit increase in salinity below the threshold, respectively, were three most important Feddes parameters for RWUa estimation in HYDRUS-1D. In addition, the effects of soil salinity and precipitation frequencies were stronger than maximum root depth on the order of the parameters’ impacts on RWUa. Our study suggested that h1, h2, h3h, and h3l might be determined by an economical method (e.g. literature review) in saline soils with limited observations, but it is better to calibrate wilting point (h4) and salt stress parameters (ht and Sp) based on local measurements.

Ectopic expression of a rice plasma membrane intrinsic protein (OsPIP1;3) promotes plant growth and water uptake

2020 ◽  
Vol 102 (4) ◽  
pp. 779-796 ◽  
Author(s):  
Siyu Liu ◽  
Tatsuya Fukumoto ◽  
Patrizia Gena ◽  
Peng Feng ◽  
Qi Sun ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plant Growth ◽  
Water Uptake ◽  
Ectopic Expression ◽  
Plasma Membrane Intrinsic Protein ◽  
Intrinsic Protein

scholarly journals Effect of Bacillus mesonae H20-5 Treatment on Rhizospheric Bacterial Community of Tomato Plants under Salinity Stress

2021 ◽  
Vol 37 (6) ◽  
pp. 662-672
Author(s):  
Shin Ae Lee ◽  
Hyeon Su Kim ◽  
Mee Kyung Sang ◽  
Jaekyeong Song ◽  
Hang-Yeon Weon
Keyword(s):  
Bacterial Community ◽  
Plant Growth ◽  
Soil Salinity ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Tomato Plants ◽  
Rhizosphere Soils ◽  
Salinity Levels

Plant growth-promoting bacteria improve plant growth under abiotic stress conditions. However, their effects on microbial succession in the rhizosphere are poorly understood. In this study, the inoculants of Bacillus mesonae strain H20-5 were administered to tomato plants grown in soils with different salinity levels (EC of 2, 4, and 6 dS/m). The bacterial communities in the bulk and rhizosphere soils were examined 14 days after H20-5 treatment using Illumina MiSeq sequencing of the bacterial 16S rRNA gene. Although the abundance of H20-5 rapidly decreased in the bulk and rhizosphere soils, a shift in the bacterial community was observed following H20-5 treatment. The variation in bacterial communities due to H20-5 treatment was higher in the rhizosphere than in the bulk soils. Additionally, the bacterial species richness and diversity were greater in the H20-5 treated rhizosphere than in the control. The composition and structure of the bacterial communities varied with soil salinity levels, and those in the H20-5 treated rhizosphere soil were clustered. The members of Actinobacteria genera, including Kineosporia, Virgisporangium, Actinoplanes, Gaiella, Blastococcus, and Solirubrobacter, were enriched in the H20-5 treated rhizosphere soils. The microbial co-occurrence network of the bacterial community in the H20-5 treated rhizosphere soils had more modules and keystone taxa compared to the control. These findings revealed that the strain H20-5 induced systemic tolerance in tomato plants and influenced the diversity, composition, structure, and network of bacterial communities. The bacterial community in the H20-5 treated rhizosphere soils also appeared to be relatively stable to soil salinity changes.

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