Impact Of Soil Salinity Research Articles

A Novel Hybrid Deep Learning Framework for Evaluating Field Evapotranspiration Considering the Impact of Soil Salinity

AbstractAccurate evaluation of evapotranspiration (ET) is crucial for efficient agricultural water management. Data‐driven models exhibit strong predictive ET capabilities, yet significant limitations like naive extrapolation hamper wider generalization. In this perspective, we explore a novel hybrid deep learning (DL) framework to integrate domain knowledge and demonstrate its potential for evaluating ET under the influence of soil salinity. Specifically, we integrated physical constraints from process models (Penman‐Monteith or Shuttleworth‐Wallace) and salinity‐induced stomatal stress mechanisms into the DL algorithm, and evaluated its performance by comparing four diverse scenarios. Results demonstrate that hybrid DL framework offers a promising alternative for ET estimation, achieving comparable accuracy to pure DL during training and validation. Nonetheless, due to the limited available measurements, data‐driven model may not adequately capture plant responses to salt stress, leading to significant prediction biases observed during independent testing. Encouragingly, the hybrid DL model (DL‐SS) integrating Shuttleworth‐Wallace and salinity‐induced stomatal stress mechanisms demonstrated enhanced interpretability, generalizability, and extrapolation capabilities. During testing, DL‐SS consistently showed optimal performance, yielding root mean square error (RMSE) values of 37.4 W m−2 for sunflower and 39.2 W m−2 for maize. Compared to traditional Jarvis‐type approaches (JPM and JSW) and pure DL model during testing, DL‐SS achieved substantial reductions in RMSE values: 51%, 33%, and 43% for sunflower, and 45%, 31%, and 35% for maize, respectively. These findings highlight the importance of integrating prior scientific knowledge into data‐driven models to enhance extrapolation capability of ET modeling, especially in salinized regions where conventional models may struggle.

The impact of soil salinity on the chemical properties of soil at Hatiya Upazila, a remote area of Noakhali, Bangladesh

The impact of soil salinity on the chemical properties of soil at Hatiya Upazila, a remote area of Noakhali, Bangladesh

Evaluating seed germination and early seedling growth of wild medicinal plants for saline soil cultivation

The impact of soil salinity on various wild plant species, including Peucedanum japonicum, Astragalus membranaceus, Lepidium sativum, Acyranthes bidentata, and Platycodon grandiflorum, was investigated in this study. Different concentrations of sodium chloride (NaCl) were used to induce salt stress, and the salt sensitivity index was employed to assess species-specific responses. Among the plants studied, Lepidium sativum exhibited the lowest sensitivity to salt stress during germination across all NaCl concentrations. For instance, at 50 mM NaCl, there were decreases of 7.2% in germination percentage, 4.22% in germination energy, 0.35% in germination index, 7.2% in peak value, and 11.99% in germination value. These percentages decreased further, ranging from 15.30% to 30.92%, at 100 mM NaCl, and more substantially at 150 mM NaCl, where reductions ranged from 42.94% to 66.26%, except for the germination rate, which only decreased by 0.05%. Conversely, Peucedanum japonicum demonstrated the highest sensitivity, experiencing reductions ranging from 27.46% to 100% at 50 mM NaCl, and complete reductions (100%) at 100 and 150 mM NaCl concentrations across all evaluated parameters. In terms of seedling growth, Acyranthes bidentata displayed the lowest sensitivity, with minimal reductions observed in various parameters, while Lepidium sativum showed significant reductions in several aspects of seedling growth under salt stress. The study underscored genetic variation in response to salt stress among the evaluated plant species, suggesting Acyranthes bidentate as a promising candidate for cultivation under salt-stress conditions. This information holds significance for utilizing unfavorable lands for plant cultivation.

Effects of groundwater and seasonal streamflow on the symbiotic nitrogen fixation of deep-rooted legumes in a dryland floodplain

Biological nitrogen fixation of deep-rooted legumes is a major pathway of nitrogen (N) inputs to drylands. Water sources including groundwater and streamflow are vital to the growth of deep-rooted legumes in drylands, but it is unclear how their different availability and biochemical properties may influence plant N fixation. We established two sampling transects at the southern fringe of the Taklimakan Desert (Xinjiang province, north-west China) to study the effects of both the groundwater depth and distance to a seasonally active river on the N fixation rate of Alhagi sparsifolia, a dominant deep-rooted legume species. We quantified the N fixation rate of A. sparsifolia using the 15N natural abundance method, and related variation in N fixation to water source use and soil biochemical properties along the two transects. The N fixation rate of A. sparsifolia decreased with groundwater depth and increased with distance from the river channel. Instead of variation in the water source or nutrient concentrations, we found that the gradient in salinity formed by groundwater flow and streamflow was most responsible for the spatial pattern in N fixation of A. sparsifolia. In many dryland regions, water availability controls the spatial variability of symbiotic N fixation along hydrological gradients. Our study system provides a contrasting condition where salinity most strongly regulates N fixation. In addition to understanding the important role of variation in water source and nutrient availability, our study suggests that the impact of soil salinity in mediating N fixation in dryland ecosystems is deserving of attention.

Impact of soil salinity on groundwater chemistry in semi-arid regions in Western India: Insights from major ion and stable isotopic [formula omitted] characteristics.

Detailed geochemical and stable isotopic (δDH2O, δ18OH2O, and δ13CDIC) study of groundwater samples (n = 74) from a semi-arid region in Western India was carried out to constrain their solute sources and sub-surface weathering processes. Na+, Cl−, and HCO3− dominate major ion chemistry. This type of chemistry points to a significant solute supply from the salt-affected soils and bedrock dissolution. The average δ18O and δD in our groundwater samples are similar to their corresponding values in precipitation samples. Spatial variability of the δ18O and δD data depicts the impact of continental effect and variable extent of evaporation in this region. The δ18O-δD cross-plot yields a lower slope (5.2 ± 0.5) than that of the global meteoric water line (∼8), confirming the significant impact of evaporation on groundwater hydrology. δ13CDIC values vary between −7.3‰ and −16.4‰ (average = −9.7‰ ± 1.7‰), and first-order binary mixing calculation shows that about 75 (±16) % of the DIC in these samples are supplied via carbonate dissolution (range: 35–100%). Inverse model calculations involving elemental ratios of major ions show that the solutes are mainly supplied through salt-affected soils (30 ± 22%), with sub-ordinate contributions from rain (31 ± 13%), silicate (23 ± 12%) and carbonate (15 ± 13%). These estimates are consistent with the formation of salt-affected soils via evaporative water loss in semi-arid regions and the faster dissolution kinetics of these soil salts. The outcomes of this study underscore distinctly different compositions of semi-arid groundwater reservoirs, which has implications for drinking and irrigation usage.

Time-course RNA-sequencing and Co-expression Modules Revealed a Critical Salt Response Regulatory Network in Apple

As one of the most important fruit tree crops, apple (Malus ×domestica), is faced with the serious impact of soil salinization. However, the underlying genetic and regulatory network remains elusive. Here, we adopted time-course RNA sequencing to decipher the genetic basis and regulatory module of apple in response to salt stress. Among a series of intense changes in genes at each time point, the critical genes in the mitogen-activated protein kinase signaling pathway were highly consistent with the duration of the stress treatment. Moreover, Salt Overly Sensitive 1 (SOS1) genes were identified and predicted to play important roles in the response process. We constructed coexpression modules and explored modules significantly associated with stress. SOS genes were identified in the hub genes, suggesting a critical role. Interestingly, transcription factors were also identified and predicted to cointeract with SOS genes in the hub genes of the coexpression module [e.g., HB7 (MD01G1226600), WRKY33 (MD12G1181000), and ERF106 (MD07G1248700)]. Collectively, our exploration and findings provide a reference and data resource for the study of genetic and salt regulatory networks in apple.

Impact of Soil Salinity on Citrus: A Review

Citrus fruits are one of the most important fruit crops in the world. However, these are vulnerable to a variety of environmental stresses, including drought, over watering (water logging), extreme temperatures (cold, frost, and heat), salinity, and mineral toxicity. Above these factors, salinity is the one of the most significant. Because of its hyperosmotic and hyperionic effects on the soil rhizosphere, salinity is an abiotic factor that has detrimental effect of reducing plant development and yield. Citrus is a salt-susceptible crop as compared to other fruit crops, because citrus development and yield are dramatically reduced under salt stress conditions. There are a variety of approaches that can be used to mitigate the harmful effects of salinity, including alternative irrigation and the selection of salt-resistant root stocks. This review will therefore, concentrate on the influence of soil salinity on citrus production and feasible mitigation techniques to reduce production losses.

Impact of Soil Salinity on Soil Dielectric Constant and Soil Moisture Retrieval From Active Microwave Remote Sensing

Impact of Soil Salinity on Soil Dielectric Constant and Soil Moisture Retrieval From Active Microwave Remote Sensing

Seed provenance affects salt tolerance and germination response of the habitat-indifferent Salsola drummondii halophyte in the arid Arabian deserts

Few species can survive well in both salty and non-salty soils (i.e., the habitat-indifferent halophytes). Little is known about the impact of soil salinity in different habitats on salt tolerance during seed germination. This study assesses effects of seed provenance of Salsola drummondii, a habitat-indifferent halophyte, on the individual effects and interactions between salt tolerance, photoperiod and thermoperiod on final germination, germination rate index (GRI) and recovery of germination from salt solutions. Seeds collected from plants grown in salty and non-salty soils were germinated in six salt solutions and incubated at three thermoperiod and two photoperiod regimes. Seeds were able to germinate and recover their germination in up to 1000 mM NaCl. Seeds from plants of non-salty soils germinated significantly better in up to 800 mM than those from salty soils, but the reverse was true at 1000 mM. The increase in salinity did not significantly affect GRI. Germination recovery was greater for seeds of plants from non-salty than for those from salty soils and for seeds germinated at lower than at higher thermoperiods. GRI of germination recovery increased with the increase in salinity level and was significantly higher for seeds of non-salty than of salty soils. Despite seeds of the two habitats are able to disperse to each other’s habitat, they differed in dormancy, GRI, and response to photoperiod and thermoperiod. Such difference could be considered the physiological basis for environmental cues that determine the proper space and time of germination that help in successful seedling establishment.

Impact of Soil Salinity on Barley Allelopathic Potential and Main Secondary Metabolites Gramine and Hordenine

Crop allelopathy is a useful tool in integrated weed suppression. Although the abiotic stresses affect the produced secondary metabolites, the impact of soil salinity on crop allelopathic potential under field conditions has not been investigated. So, the effect of soil salinity on the allelopathic activity of 18 allelopathic barley (Hordeum vulgare L.) varieties was investigated. The allelopathy of barley grown on saline and non-saline soils was investigated during a 2-year field experiment using the Perlite-based bioassay with rigid ryegrass (Lolium rigidum L.) as plant indicator. The two main allelopathic substances in barley, gramine and hordenine, were determined using the high-performance liquid chromatography with tandem mass spectrometry. The results indicated that rigid ryegrass germination and root length were adversely affected by the barley aqueous extracts. The secondary metabolite gramine was detected in greater concentrations than those of hordenine. For most barley varieties, soil salinity reduced the phytotoxicity of aqueous extracts, as well as the concentration of gramine. However, gramine and hordenine were not highly correlated with the barley extract phytotoxicity, indicating the possible involvement of other allelopathic substances. In conclusion, the barley allelopathic potential probably decreases in soils with high salinity.

Impact of soil salinity on grain yield and aromatic compound in Thai Hom Mali rice cv. Khao Dawk Mali 105

Impact of soil salinity on grain yield and aromatic compound in Thai Hom Mali rice cv. Khao Dawk Mali 105

Impact of soil salinity on grain yield and aromatic compound in Thai Hom Mali rice cv. Khao Dawk Mali 105

Impact of soil salinity on grain yield and aromatic compound in Thai Hom Mali rice cv. Khao Dawk Mali 105

Impact of Soil Salinity on the Cowpea Nodule-Microbiome and the Isolation of Halotolerant PGPR Strains to Promote Plant Growth under Salinity Stress

Cowpea is one of the major legumes cultivated in arid and semiarid regions of the world. Four soil-microbial samples (SS-1 through SS-4) collected from semiarid soils in Punjab, Pakistan were planted with cowpea (Vigna unguiculata) crops, which were grown under salinity stress to analyze bacterial composition in the rhizosphere and within nodules using cultivation-dependent and -independent methods. Two varieties, 603 and the salt-tolerant CB 46, were each inoculated with or without the four different native soil samples or grown in medium either N-deficient (−N) or supplemented with N (+N). Plants inoculated with soil samples SS-2 and SS-4 grew better than plants inoculated with SS-1- and SS-3 and grew comparably with the +N controls. Environmental DNA (eDNA) was isolated from SS-1 and SS-4, and, by 16S ribosomal RNA sequencing, the soil microbiomes consisted mainly of Actinobacteria, Firmicutes, Proteobacteria, and other nonproteobacterial genera. However, analysis of eDNA isolated from cowpea nodules established by the trap plants showed that the nodule microbiome consisted almost exclusively of proteobacterial sequences, particularly species of Bradyrhizobium. Bacteria were isolated from both soils and nodules, and 34 of the 51 isolates tested positive for plant-growth-promoting rhizobacteria traits in plate assays. Many could serve as future inocula for crops in arid soils. The discrepancy between the types of bacteria isolated by culturing bacteria isolated from surface-sterilized cowpea nodules (proteobacteria and nonproteobacteria) versus those detected by sequencing DNA isolated from the nodules (proteobacteria) from cowpea nodules (proteobacteria and nonproteobacteria) versus those detected in the nodule microbiome (proteobacteria) needs further study.

Impact of soil salinity, texture and measurement frequency on the relations between soil moisture and 20 MHz–3 GHz dielectric permittivity spectrum for soils of medium texture

Dielectric sensors are a popular choice for soil moisture determination. However, the output of many of these devices, especially those operating at frequencies in the MHz range, can be significantly affected by the influence of soil salinity and texture. The aim of this paper is to examine the impact of salinity, texture and measurement frequency on dielectric permittivity – soil moisture calibration curves for ten soils of medium texture in the frequency range from 20 MHz to 3 GHz based on the complex dielectric permittivity spectra measured with the use of a coaxial transmission line cell connected to a vector-network-analyzer. The use of laboratory-measured spectra ensures that at all frequencies dielectric permittivity is measured at the same conditions with no influence of factors such as different sensitivity zone or various installation conditions, as in the case of comparing individual sensors operating at various frequencies. The obtained relations were comparable to the calibration curves of several capacitance/impedance sensors operating at corresponding frequencies. Calibration curves for apparent permittivity, which were obtained with the use of simulations in the time domain based on the measured spectra, were also determined for the tested soils. Even though the tested soils did not include soils with high clay content, the impact of soil texture on the calibration curves was observed. Results confirmed that the influence of soil salinity and texture on dielectric permittivity was the most significant in the lower part of the frequency spectrum, while the smallest impact of these factors was observed at frequencies of several hundred MHz and above.

Impact of Soil Salinity and Different Levels of Nitrogen and Phosphorus Fertilization on the Productivity of some Flax Cultivars

Impact of Soil Salinity and Different Levels of Nitrogen and Phosphorus Fertilization on the Productivity of some Flax Cultivars

The impact of soil salinity on maize agriculture: An experimental archaeology approach

This article uses experimental archaeology to provide empirical data on the impact of soil salinization on ancient maize agriculture. Hopi blue maize was experimentally grown in a drought-prone soil containing an extremely high level (50%) of evaporite mineral salts (CaCO3, CaSO4, and NaCl) in order to evaluate their effect on agricultural productivity. A control group of plants was grown in the absence of mineral salts. All of plants, which were companion planted with beans and squash, were adversely impacted by evaporite mineral salts. Maize grown alone in CaCO3−, CaSO4−, and NaCl-enriched soil exceeded the height of the control plants because the mineral salts acted as a fertilizer. Plants grown in NaCl-enriched soil produced cobbs that were reduced in size and kernel number. These findings suggest that CaCO3 and CaSO4, the most common evaporite mineral salts found in soil, would not have adversely impacted Ancestral Puebloan maize agriculture.

Impact of soil salinity on the microbial structure of halophyte rhizosphere microbiome.

The rhizosphere microbiome plays a significant role in the life of plants in promoting plant survival under adverse conditions. However, limited information is available about microbial diversity in saline environments. In the current study, we compared the composition of the rhizosphere microbiomes of the halophytes Urochloa, Kochia, Salsola, and Atriplex living in moderate and high salinity environments (Khewra salt mines; Pakistan) with that of the non-halophyte Triticum. Soil microbiomes analysis using pyrosequencing of 16S rRNA gene indicated that Actinobacteria were dominant in saline soil samples whereas Proteobacteria predominated in non-saline soil samples. Firmicutes, Acidobacteria, Bacteriodetes and Thaumarchaeota were predominant phyla in saline and non-saline soils, whereas Cyanobacteria, Verrucomicrobia, Gemmatimonadetes and the unclassified WPS-2 were less abundant. Sequences from Euryarchaeota, Ignavibacteriae, and Nanohaloarchaeota were identified only from the rhizosphere of halophytes. Dominant halophilic bacteria and archaea identified in this study included Agrococcus, Armatimonadetes gp4, Halalkalicoccus, Haloferula and Halobacterium. Our analysis showed that increases in soil salinity correlated with significant differences in the alpha and beta diversity of the microbial communities across saline and non-saline soil samples. Having a complete inventory of the soil bacteria from different saline environments in Pakistan will help in the discovery of potential inoculants for crops growing on salt-affected land.

The influence of host genotype and salt stress on the seed endophytic community of salt-sensitive and salt-tolerant rice cultivars

BackgroundInherent characteristics and changes in the physiology of rice as it attains salt tolerance affect the colonizing bacterial endophytic communities of the rice seeds. These transmissible endophytes also serve as a source of the plant’s microbial community and concurrently respond to the host and environmental conditions. This study explores the influence of the rice host as well as the impact of soil salinity on the community structure and diversity of seed bacterial endophytes of rice with varying tolerance to salt stress. Endophytic bacterial diversity was studied through culture-dependent technique and Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis.ResultsResults revealed considerably diverse communities of bacterial endophytes in the interior of rice seeds. The overall endophytic bacterial communities of the indica rice seeds based on 16S rRNA analysis of clones and isolates are dominated by phylum Proteobacteria followed by Actinobacteria and Firmicutes. Community profiles show common ribotypes found in all cultivars of the indica subspecies representing potential core microbiota belonging to Curtobacterium, Flavobacterium, Enterobacter, Xanthomonas, Herbaspirillum, Microbacterium and Stenotrophomonas. Clustering analysis shows that the host genotype mainly influences the seed endophytic community of the different rice cultivars. Under salt stress conditions, endophytic communities of the salt-sensitive and salt-tolerant rice cultivars shift their dominance to bacterial groups belonging to Flavobacterium, Pantoea, Enterobacter, Microbacterium, Kosakonia and Curtobacterium.ConclusionThe endophytic communities of rice indica seeds are shaped by the hosts’ genotype, their physiological adaptation to salt stress and phylogenetic relatedness. Under salt stress conditions, a few groups of bacterial communities become prominent causing a shift in bacterial diversity and dominance.

Effects of drip irrigation levels on soil water, salinity and wheat growth in North China

Northwest China has long suffered from serious water scarcity and soil salinization. It is important to reduce the impact of soil salinization on crop growth and improve water-use efficiency (WUE) through efficient utilization of the limited water resources. This study examined the effects of drip irrigation (DI) on the water and salinity distribution in soil planted with spring wheat, a representative crop in Northwest of China. An in-depth analysis of the leaching of salts by irrigation water and salt accumulation in the soil profile was performed. An irrigation experiment with four irrigation levels (315 mm, 360 mm, 405 mm, and 450 mm) was conducted to investigate the effects of the amount of irrigation water (AIW) on the physiology and growth, photosynthesis, yield, and WUE of spring wheat. The results showed that applying the irrigation water at 405 mm can improve the distribution uniformity of soil water and WUE. Due to the leaching of salts by irrigation water, an increase in the AIW resulted in a higher desalination rate, a lower salt accumulation rate, and a greater depth of desalination. When the AIW was 315 mm, 360 mm, 405 mm and 450 mm, the average depth of desalination was 40 cm, 43 cm, 47 cm and 50 cm, respectively. The plant height, aboveground biomass, leaf area, and wheat ear mass varied significantly with the AIW. As the AIW increased, the average plant height increased, while the aboveground biomass, leaf area, and wheat ear mass increased first and then decreased. The net photosynthetic rate, transpiration rate, and stomatal conductance all increased greatly with increasing AIW, but excessive AIW could lower the net photosynthetic rate. The 405 mm treatment was the recommended irrigation level with the best wheat yield and water productivity at 7631.19 kg/hm2 and 1.88 kg/m3, respectively. Keywords: drip irrigation; spring wheat; spatial distribution; desalination; water use efficiency DOI: 10.25165/j.ijabe.20181101.3775 Citation: Wang Z H, Liao R K, Lin H, Jiang G J, He X L, Wu W Y, et al. Effects of drip irrigation levels on soil water, salinity and wheat growth in North China. Int J Agric & Biol Eng, 2018; 11(1): 146–156.

Springtails of flooded meadows along Matsalu Bay and the Kasari River, Estonia

The brackish conditions of the Baltic Sea create special habitats in coastal meadow soils surrounding Matsalu Bay. The floodplains of the Kasari River are periodically flooded by fresh water. In the eastern part of Matsalu Bay and in the delta of the river, brackish and fresh water can be mixed due to strong winds from the west or due to exceptionally large amounts of fresh water flowing from the river in the spring. The aim of this study was to find out how flood and habitat soil salinity influence the abundance and diversity of springtail communities on flooded meadows. The studied meadows were grouped to four types by distance of study sites from the open sea and by soil electroconductivity: fresh floodplain, wet floodplain, transitional and coastal grasslands. Springtail communities on temporarily flooded meadows along Matsalu Bay and the Kasari River consist of 20 − 30 species per meadow type, species Metaphorura affinis, Willemia anophthalma, Brachystomella parvula, Folsomia quadrioculata were abundant in soil of all types of meadows. Our results confirmed that flooding is an important factor in shaping soil communities. Long-term flood had strong negative effect on springtail communities’ abundance and diversity. However, there was no such negative effect of flood on meadows with shorter flooding period, for several species the flood was positive factor increasing the abundance. Flooding brackish sea water is the reason for higher electroconductivity of meadow soils negatively influencing the diversity of springtail communities. The abundance of several species was the highest in soil of coastal grasslands (Agrenia bidenticulata, Folsomia sexoculata, Podura aquatica, Sminthurides schoetti) despite the higher salinity of soil. The impact of flood duration on the composition of communities by life forms seemed to be less important than the impact of soil salinity, saline soil was not a suitable habitat for euedaphic springtails.