Articles de revues : « High-salinity soil »

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Bethune, M. G., et T. J. Batey. « Impact on soil hydraulic properties resulting from irrigating salinesodic soils with low salinity water ». Australian Journal of Experimental Agriculture 42, n^o 3 (2002) : 273. http://dx.doi.org/10.1071/ea00142.

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Irrigation-induced salinity is a serious problem facing irrigated areas in the Murray–Darling Basin of Australia. Groundwater pumping with farm re-use for irrigation is a key strategy for controlling salinity in these irrigation areas. However, the re-use of highly saline–sodic groundwater for irrigation leads to accumulation of sodium in the soil profile and can result in sodic soils. Leaching of saline–sodic soils by winter rainfall and low salinity irrigation waters are 2 management scenarios likely to exacerbate sodicity problems. Characteristic to sodic soils is poor soil structure and potentially reduced soil permeability. Two indicators of soil permeability are infiltration rate and hydraulic conductivity. A replicated plot experiment was conducted to examine the long-term impact of irrigation with saline–sodic water on soil permeability. High levels of soil sodicity (ESP up to 45%) resulted from 10 years of saline irrigation. Over this period, leaching by winter rainfall did not result in long-term impacts on soil hydraulic properties. Measured soil hydraulic properties increased linearly with the salinity of the applied irrigation water. Leaching by irrigating with low salinity water for 13 months decreased soil salinity and sodicity in the topsoil. The resulting reduction in steady-state infiltration indicates soil structural decline of the topsoil. This trial shows that groundwater re-use on pasture will result in high sodium levels in the soil. Sodicity-related soil structural problems are unlikely to develop where there is consistent groundwater irrigation of pasture. However, structural decline of these soils is likely following the cessation of groundwater re-use.

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Shaw, E. Ashley, et Diana H. Wall. « Biotic Interactions in Experimental Antarctic Soil Microcosms Vary with Abiotic Stress ». Soil Systems 3, n^o 3 (27 août 2019) : 57. http://dx.doi.org/10.3390/soilsystems3030057.

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Biotic interactions structure ecological communities but abiotic factors affect the strength of these relationships. These interactions are difficult to study in soils due to their vast biodiversity and the many environmental factors that affect soil species. The McMurdo Dry Valleys (MDV), Antarctica, are relatively simple soil ecosystems compared to temperate soils, making them an excellent study system for the trophic relationships of soil. Soil microbes and relatively few species of nematodes, rotifers, tardigrades, springtails, and mites are patchily distributed across the cold, dry landscape, which lacks vascular plants and terrestrial vertebrates. However, glacier and permafrost melt are expected to cause shifts in soil moisture and solutes across this ecosystem. To test how increased moisture and salinity affect soil invertebrates and their biotic interactions, we established a laboratory microcosm experiment (4 community × 2 moisture × 2 salinity treatments). Community treatments were: (1) Bacteria only (control), (2) Scottnema (S. lindsayae + bacteria), (3) Eudorylaimus (E. antarcticus + bacteria), and (4) Mixed (S. lindsayae + E. antarcticus + bacteria). Salinity and moisture treatments were control and high. High moisture reduced S. lindsayae adults, while high salinity reduced the total S. lindsayae population. We found that S. lindsayae exerted top-down control over soil bacteria populations, but this effect was dependent on salinity treatment. In the high salinity treatment, bacteria were released from top-down pressure as S. lindsayae declined. Ours was the first study to empirically demonstrate, although in lab microcosm conditions, top-down control in the MDV soil food web.

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Aboelsoud, Hesham M., Mohamed A. E. AbdelRahman, Ahmed M. S. Kheir, Mona S. M. Eid, Khalil A. Ammar, Tamer H. Khalifa et Antonio Scopa. « Quantitative Estimation of Saline-Soil Amelioration Using Remote-Sensing Indices in Arid Land for Better Management ». Land 11, n^o 7 (8 juillet 2022) : 1041. http://dx.doi.org/10.3390/land11071041.

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Soil salinity and sodicity are significant issues worldwide. In particular, they represent the most dominant types of degraded lands, especially in arid and semi-arid regions with minimal rainfall. Furthermore, in these areas, human activities mainly contribute to increasing the degree of soil salinity, especially in dry areas. This study developed a model for mapping soil salinity and sodicity using remote sensing and geographic information systems (GIS). It also provided salinity management techniques (leaching and gypsum requirements) to ameliorate soil and improve crop productivity. The model results showed a high correlation between the soil electrical conductivity (ECe) and remote-sensing spectral indices SIA, SI3, VSSI, and SI9 (R2 = 0.90, 0.89, 0.87, and 0.83), respectively. In contrast, it showed a low correlation between ECe and SI5 (R2 = 0.21). The salt-affected soils in the study area cover about 56% of cultivated land, of which the spatial distribution of different soil salinity levels ranged from low soil salinity of 44% of the salinized cultivated land, moderate soil salinity of 27% of salinized cultivated land, high soil salinity of 29% of the salinized cultivated land, and extreme soil salinity of 1% of the salinized cultivated land. The leaching water requirement (LR) depths ranged from 0.1 to 0.30 m ha−1, while the gypsum requirement (GR) ranged from 0.1 to 9 ton ha−1.

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Aboelsoud, Hesham, Bernard Engel et Khaled Gad. « Effect of Planting Methods and Gypsum Application on Yield and Water Productivity of Wheat under Salinity Conditions in North Nile Delta ». Agronomy 10, n^o 6 (16 juin 2020) : 853. http://dx.doi.org/10.3390/agronomy10060853.

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Salinity and water shortage are the most important factors limiting crop productivity, so increasing the productivity of salt-affected soils is important to address the global food gap. Two field experiments were conducted under typical farm conditions in the North Nile Delta to study the effect of planting methods and gypsum application on wheat yield and water productivity under a range of water and soil salinity levels. In the first experiment, wheat was treated with gypsum (25%, 75%, and 100% gypsum-requirement) with moderate or high salinity in soil and water. The second experiment was conducted for two seasons at two sites to test three planting methods (flat, 60-cm furrows, and 120-cm raised-beds) under normal or high salinity levels of both soil and water. The results showed that gypsum alleviated the hazardous effects of salinity stress on grain yield. Raised furrows or beds under higher salinity levels increased soil salinity, and soil salinity was slightly increased with flat plots. Higher yields, water savings, and water productivities were achieved with raised furrows or beds under normal salinity. To improve yield under normal salinity conditions, raised beds are the recommended planting method. Furthermore, gypsum application in cultivated fields can mitigate the negative effects of salinity stress.

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Knewtson, Sharon J. B., M. B. Kirkham, Rhonda R. Janke, Leigh W. Murray et Edward E. Carey. « Soil Quality After Eight Years Under High Tunnels ». HortScience 47, n^o 11 (novembre 2012) : 1630–33. http://dx.doi.org/10.21273/hortsci.47.11.1630.

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The sustainability of soil quality under high tunnels will influence management of high tunnels currently in use and grower decisions regarding design and management of new high tunnels to be constructed. Soil quality was quantified using measures of soil pH, salinity, total carbon, and particulate organic matter (POM) carbon in a silt loam soil that had been in vegetable production under high tunnels at the research station in Olathe, KS, for eight years. Soil under high tunnels was compared with that in adjacent fields in both a conventional and an organic management system. The eight-year presence of high tunnels under the conventional management system resulted in increased soil pH and salinity but did not affect soil carbon. In the organic management system, high tunnels did not affect soil pH, increased soil salinity, and influenced soil carbon (C) pools with an increase in POM carbon. The increases in soil salinity were not enough to be detrimental to crops. These results indicate that soil quality was not adversely affected by eight years under stationary high tunnels managed with conventionally or organically produced vegetable crops.

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Mohammadi, Mohammad Hossein, et Mahnaz Khataar. « A simple numerical model to estimate water availability in saline soils ». Soil Research 56, n^o 3 (2018) : 264. http://dx.doi.org/10.1071/sr17081.

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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.

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Krzyżaniak, M., et J. Lemanowicz. « Enzymatic activity of the Kuyavia Mollic Gleysols (Poland) against their chemical properties ; ». Plant, Soil and Environment 59, No. 8 (31 juillet 2013) : 359–65. http://dx.doi.org/10.17221/211/2013-pse.

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The research results have shown that the enzyme pH index (0.49–0.83) confirmed the neutral or alkaline nature of the soils. Neither the changes in the content of available phosphorus nor in the activity of dehydrogenases, catalase, alkaline and acid phosphatase in soil were due to the factors triggering soil salinity; they were a result of the naturally high content of carbon of organic compounds, which was statistically verified with the analysis of correlation between the parameters. There were recorded highly significant values of the coefficients of correlation between the content of available phosphorus in soil and the activity of alkaline (r = 0.96; P < 0.05) and acid phosphatase (r = 0.91; P < 0.05) as well as dehydrogenase (r = 0.90; P < 0.05). To sum up, one can state that Mollic Gleysols in Inowrocław are the soils undergoing seasonal salinity; however, a high content of ions responsible for salinity is balanced with a high content of organic carbon, humus, phosphorus and calcium directly affecting the fertility of the soils analyzed. The activity of the enzymes depended on the natural content of carbon of organic compounds and not on the factors affecting the soil salinity, which points to the potential of such tests for soil environment monitoring.

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Liang, Xiaolong, Xiaoyu Wang, Ning Zhang et Bingxue Li. « Biogeographical Patterns and Assembly of Bacterial Communities in Saline Soils of Northeast China ». Microorganisms 10, n^o 9 (5 septembre 2022) : 1787. http://dx.doi.org/10.3390/microorganisms10091787.

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Increasing salinity undermines soil fertility and imposes great threats to soil ecosystem productivity and ecological sustainability. Microbes with the ability to adapt to environmental adversity have gained increasing attention for maintenance and restoration of the salt-affected soil ecosystem structure and functioning; however, the characterization of microbial communities in saline–sodic soils remains limited. This study characterized the bacterial community composition and diversity in saline–sodic soils along a latitude gradient across Northeast China, aiming to reveal the mechanism of physicochemical and geographic characteristics shaping the soil bacterial communities. Our results showed that the bacterial community composition and diversity were significantly impacted by soil pH, electrical conductivity, Na+, K+, Cl−, and CO32−. Significant differences in bacterial diversity were revealed along the latitude gradient, and the soil factors accounted for 58.58% of the total variations in bacterial community composition. Proteobacteria, Actinobacteria, Gemmatimonadetes, Chloroflexi, and Bacteroidetes were dominant across all samples. Actinobacteria and Gemmatimonadetes were significantly enriched in high soil sodicity and salinity, while Acidobacteria and Proteobacteria were suppressed by high pH and salt stress in the saline–sodic soils. Increase in soil pH and salinity significantly decreased bacterial species richness and diversity. Community composition analysis indicated that bacterial taxonomic groups (e.g., Bacillus, Egicoccus, Truepera, Halomonas, and Nitrolancea) that may adapt well to high salinity were greatly enriched in the examined soils. The findings collectively evidenced that bacterial community composition and diversity in a broad biographic scale were determined by niche-based environmental characteristics and biotic interactions. The profiling of the soil bacterial communities along the latitude gradient will also provide a basis for a better understanding of the salt-affected soil ecosystem functioning and restoration of these soil ecosystems.

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Ergashovich, Kholliyev Askar, Norboyeva Umida Toshtemirovna, Jabborov Bakhtiyor Iskandarovich et Norboyeva Nargiza Toshtemirovna. « Soil Salinity And Sustainability Of Cotton Plant ». American Journal of Agriculture and Biomedical Engineering 03, n^o 04 (22 avril 2021) : 12–19. http://dx.doi.org/10.37547/tajabe/volume03issue04-03.

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The following article deals with the data obtained as a result of the effect of soil salinity on the physiological properties and tolerance levels of medium-fibre cotton varieties. Also, changes in physiological processes under the influence of different levels of salinity and differences in the adaptive properties of varieties have been noted. Salinity had a negative impact on all studied cotton varieties, while the radical decline in yield and its quality was observed in varieties with high levels of adaptability and hardiness.

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Zhang, Lei, Li-ping Jing, Ning-wei Wang, Chen Fang, Yong-qiang Li et Zhen-dong Shan. « Electro-Osmosis Chemical Treatment of High-Salinity Soft Marine Soils : Laboratory Tests ». Open Civil Engineering Journal 11, n^o 1 (31 janvier 2017) : 109–20. http://dx.doi.org/10.2174/1874149501711010109.

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The electro-osmosis chemical treatment (ECT) is a useful method for improving soil strength. Some laboratory tests on ECT for strengthening high-salinity soft marine soils were investigated using self-designed laboratory facilities in this research. This study focused on improving the mechanical properties by using ECT method and analyzed the effects of using CaCl2 solution on soil strength owing to the electrolyte is an important factor for improving the bearing capacity of the high-salinity marine soils. Three groups of tests with different time for consolidation were performed to analyze the effective consolidation time on the ECT. In addition, several practical issues, including the current, voltage, energy consumption and the bearing capacity of the treated soils before and after experiments, were considered in the tests. The laboratory tests results demonstrated that the ECT technique is an effective method for improving the high-salinity marine soft soils. Furthermore, the definition of the effective time for consolidation was proposed for the ECT of high-salinity soft marine soils to improve the feasibility and economical efficiency of the ECT. This study provides some references and suggestions for practical application of the ECT technique for marine soft soils.

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Barrett-Lennard, Edward G., Geoffrey C. Anderson, Karen W. Holmes et Aidan Sinnott. « High soil sodicity and alkalinity cause transient salinity in south-western Australia ». Soil Research 54, n^o 4 (2016) : 407. http://dx.doi.org/10.1071/sr15052.

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Transient salinity associated with increased dispersion of clays is arguably one of the most economically important soil constraints in Australia because it occurs on land that is regularly cropped. However, this issue is rarely studied. This paper examines the occurrence of transient salinity on agricultural land in the south-west of Western Australia and the factors causing it. We analysed four soil datasets from the region, collected at scales varying from the entire south-west to a single paddock. A variety of soil parameters were correlated with increased electrical conductivity (EC1:5). The most significant relationships were invariably with measures of exchangeable sodium (Na+; 53–85% of variance accounted for), and this factor appears to be most responsible for transient salinity. Another parameter correlated with increased EC1:5 was alkalinity. This has been associated with the increased dispersion of kaolinite and consequent decreases in soil hydraulic conductivity; kaolinite is the most common clay mineral in the south-west of Western Australia. Other factors correlated with increased EC1:5 were increasing clay, increasing depth in the soil profile and decreasing rainfall. These factors are environmental indicators of transient salinity. Affected soils might be ameliorated by application of agents to increase soil hydraulic conductivity, such as gypsum and/or elemental sulfur.

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Kuroda, Naoki, Katsuhide Yokoyama et Tadaharu Ishikawa. « Development of a Practical Model for Predicting Soil Salinity in a Salt Marsh in the Arakawa River Estuary ». Water 13, n^o 15 (28 juillet 2021) : 2054. http://dx.doi.org/10.3390/w13152054.

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Our group has studied the spatiotemporal variation of soil and water salinity in an artificial salt marsh along the Arakawa River estuary and developed a practical model for predicting soil salinity. The salinity of the salt marsh and the water level of a nearby channel were measured once a month for 13 consecutive months. The vertical profile of the soil salinity in the salt marsh was measured once monthly over the same period. A numerical flow simulation adopting the shallow water model faithfully reproduced the salinity variation in the salt marsh. Further, we developed a soil salinity model to estimate the soil salinity in a salt marsh in Arakawa River. The vertical distribution of the soil salinity in the salt marsh was uniform and changed at almost the same time. The hydraulic conductivity of the soil, moreover, was high. The uniform distribution of salinity and high hydraulic conductivity could be explained by the vertical and horizontal transport of salinity through channels burrowed in the soil by organisms. By combining the shallow water model and the soil salinity model, the soil salinity of the salt marsh was well reproduced. The above results suggest that a stable brackish ecotone can be created in an artificial salt marsh using our numerical model as a design tool.

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PAPADOPOULOS, I. « SOIL SALINITY AS AFFECTED BY HIGH-SULFATE WATER ». Soil Science 140, n^o 5 (novembre 1985) : 376–81. http://dx.doi.org/10.1097/00010694-198511000-00009.

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Kumar, Vikash, Nikhil Raghuvanshi, Abhay K. Pandey, Abhishek Kumar, Emily Thoday-Kennedy et Surya Kant. « Role of Halotolerant Plant Growth-Promoting Rhizobacteria in Mitigating Salinity Stress : Recent Advances and Possibilities ». Agriculture 13, n^o 1 (9 janvier 2023) : 168. http://dx.doi.org/10.3390/agriculture13010168.

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Soil salinity is one of the major abiotic constraints in agricultural ecosystems worldwide. High salinity levels have negative impacts on plant growth and yield, and affect soil physicochemical properties. Salinity also has adverse effects on the distribution and abundance of soil microorganisms. Salinity problems have previously been addressed in research, but most approaches, such as breeding for salt tolerant varieties and soil amelioration, are expensive and require years of efforts. Halotolerant plant growth-promoting rhizobacteria (HT-PGPR) secrete secondary metabolites, including osmoprotectants, exopolysaccharides, and volatile organic compounds. The importance of these compounds in promoting plant growth and reducing adverse effects under salinity stress has now been widely recognised. HT-PGPR are emerging as effective biological strategies for mitigating the harmful effects of high salinity; improving plant growth, development, and yield; and remediating degraded saline soils. This review describes the beneficial effects and growth-promoting mechanisms of various HT-PGPR, which are carried out by maintaining ion homeostasis, increasing nutrient availability, and the producing secondary metabolites, osmoprotectants, growth hormones, and volatile organic compounds. Exploring suitable HT-PGPR and applications in agriculture production systems can play a crucial role in reducing the adverse impacts of salinity stress and sustainable crop productivity.

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Sui, Na, Yu Liu et Bao Shan Wang. « Comparative Study on Photosynthetic Characteristics of Two Ecotypes of Euhalophyte Suaeda salsa L. Grown Under Natural Saline Conditions ». Advanced Materials Research 726-731 (août 2013) : 4488–93. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.4488.

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Suaeda salsa L. grown in the intertidal zone and those in high salinity soils of the Yellow River Delta were used to investigate the category and characteristic of photosynthesis and fluorescence. Results showed that the water content, Na+ and Cl- contents of the high salinity soils were lower. The temperature on the surface of soil and in the depth of 10 cm from the surface, the content of K+ and Ca2+ of the high salinity soils were significantly higher than those in the intertidal zone soils. Pn, Gs, Fv/Fm, ФPSII, the fresh weight and dry weight per plant of S. salsa grown in the high salinity soils were higher. However, Ci of S. salsa grown in the high salinity soils were lower. These suggested that S. salsa grown in the high salinity soils was mainly suffering from salt stress, while S. salsa in the intertidal zone soils was suffering from waterlogging, low temperature and salt stress together. S. salsa in the intertidal zone soils decreased light absorption and alleviated photoinhibition, but as a result the biomass was reduced.

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Guan, Zilong, Zhifeng Jia, Zhiqiang Zhao et Qiying You. « Dynamics and Distribution of Soil Salinity under Long-Term Mulched Drip Irrigation in an Arid Area of Northwestern China ». Water 11, n^o 6 (12 juin 2019) : 1225. http://dx.doi.org/10.3390/w11061225.

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Mulched drip irrigation has been widely used in agricultural planting in arid and semi-arid regions. The dynamics and distribution of soil salinity under mulched drip irrigation greatly affect crop growth and yield. However, there are still different views on the distribution and dynamics of soil salinity under long-term mulched drip irrigation due to complex factors (climate, groundwater, irrigation, and soil). Therefore, the soil salinity of newly reclaimed salt wasteland was monitored for 9 years (2008–2016), and the effects of soil water on soil salinity distribution under mulched drip irrigation have also been explored. The results indicated that the soil salinity decreased sharply in 3–4 years of implementation of mulched drip irrigation, and then began to fluctuate to different degrees and showed slight re-accumulation. During the growth period, soil salinity was relatively high at pre-sowing, and after a period of decline soil salinity tends to increase in the late harvest period. The vertical distribution of soil texture had a significant effect on the distribution of soil salinity. Salt accumulated near the soil layer transiting from coarse soil to fine soil. After a single irrigation, the soil water content in the 30–70 cm layer under the cotton plant undergoes a ‘high–low–high’ change pattern, and the soil salt firstly moved to the deep layer (below 70 cm), and then showed upward migration tendency with the weakening of irrigation water infiltration. The results may contribute to the scientific extension of mulched drip irrigation and the farmland management under long-term mulched drip irrigation.

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Gopalakrishnan, Tharani, et Lalit Kumar. « Linking Long-Term Changes in Soil Salinity to Paddy Land Abandonment in Jaffna Peninsula, Sri Lanka ». Agriculture 11, n^o 3 (5 mars 2021) : 211. http://dx.doi.org/10.3390/agriculture11030211.

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Soil salinity is a serious threat to coastal agriculture and has resulted in a significant reduction in agricultural output in many regions. Jaffna Peninsula, a semi-arid region located in the northern-most part of Sri Lanka, is also a victim of the adverse effects of coastal salinity. This study investigated long-term soil salinity changes and their link with agricultural land use changes, especially paddy land. Two Landsat images from 1988 and 2019 were used to map soil salinity distribution and changes. Another set of images was analyzed at four temporal periods to map abandoned paddy lands. A comparison of changes in soil salinity with abandoned paddy lands showed that abandoned paddy lands had significantly higher salinity than active paddy lands, confirming that increasing salts owing to the high levels of sea water intrusion in the soils, as well as higher water salinity in wells used for irrigation, could be the major drivers of degradation of paddy lands. The results also showed that there was a dramatic increase in soil salinity (1.4-fold) in the coastal lowlands of Jaffna Peninsula. 64.6% of the salinity-affected land was identified as being in the extreme saline category. In addition to reducing net arable lands, soil salinization has serious implications for food security and the livelihoods of farmers, potentially impacting the regional and national economy.

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Lilles, E. B., B. G. Purdy, S. X. Chang et S. E. Macdonald. « Soil and groundwater characteristics of saline sites supporting boreal mixedwood forests in northern Alberta ». Canadian Journal of Soil Science 90, n^o 1 (1 février 2010) : 1–14. http://dx.doi.org/10.4141/cjss08040.

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The influence of salinity on boreal forest plants is of growing concern today because oil sands mining and other energy-related industrial activities in northern Alberta and elsewhere produce large areas of salt-affected soils that require reclamation and revegetation. We characterized soils (salinity, pH, and nutrient and moisture availabilities) and groundwater at six naturally saline sites in northern Alberta which were occupied by boreal mixedwood forests dominated by aspen (Populus tremuloides Michx.) and white spruce [Picea glauca (Moench) Voss]. Salinity increased with depth in the soil profile and decreased with distance away from adjacent non-forested saline wetlands. In areas where forest vegetation existed, the electrical conductivity (ECe) of the surface soil (0-20 cm depth) was always below 4 dS m-2; chemical properties of the lower subsurface soil (50-100 cm depth) and groundwater ranged well above what has been conventionally considered to be suitable for tree growth: ECe ranged from 4 to 23 dS m-2, sodium adsorption ratio ranged from 13 to 70, and the pH of some soil horizons was above 9.0. These sites had relatively high soil moisture and nutrient availabilities, and we hypothesize that these facilitate survival of forest vegetation on these sites, despite the high levels of salinity. Key words: Salinity tolerance, electrical conductivity, sodium adsorption ratio, alkalinity, boreal forest, reclamation

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Xu, Lu, Raphael A. Viscarra Rossel, Juhwan Lee, Zhichun Wang et Hongyuan Ma. « A simple approach to estimate coastal soil salinity using digital camera images ». Soil Research 58, n^o 8 (2020) : 737. http://dx.doi.org/10.1071/sr20009.

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Soil salinisation is a global problem that hinders the sustainable development of ecosystems and agricultural production. Remote and proximal sensing technologies have been used to effectively evaluate soil salinity over large scales, but research on digital camera images is still lacking. In this study, we propose to relate the pixel brightness of soil surface digital images to the soil salinity information. We photographed the surface of 93 soils in the field at different times and weather conditions, and sampled the corresponding soils for laboratory analyses of soil salinity information. Results showed that the pixel digital numbers were related to soil salinity, especially at the intermediate and higher brightness levels. Based on this relationship, we employed random forest (RF) and partial least-squares regression (PLSR) to model soil salt content and ion concentrations, and applied root mean squared error, coefficient of determination and Lin’s concordance correlation coefficient to evaluate the accuracy of models. We found that ions with high concentration were estimated more accurately than ions with low concentrations, and RF models performed overall better than PLSR models. However, the method is only suitable for bare land of coastal soil, and verification is needed for other conditions. In conclusion, a new approach of using digital camera images has good potential to predict and manage soil salinity in the context of precision agriculture with the rapid development of unmanned aerial vehicles.

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Gelaye, Kidia K., Franz Zehetner, Willibald Loiskandl et Andreas Klik. « Comparison of growth of annual crops used for salinity bioremediation in the semi-arid irrigation area ». Plant, Soil and Environment 65, No. 4 (23 avril 2019) : 165–71. http://dx.doi.org/10.17221/499/2018-pse.

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The decline of soil organic carbon (SOC) has aggravated salinity-related problems in semi-arid irrigation areas of the Awash river basin, Ethiopia. This study aimed at evaluating the performance of potential remediation crops on saline soil and their effectiveness for remediating soil salinity and improving pH, SOC, bulk density (BD) and hydraulic conductivity (HyCo). Rhodes grass (RHG), alfalfa (ALF), sudangrass (SUG) and blue panicgrass (Retz) (BPG) were grown in saline (3–13.9 dS/m) field plots. The crop biomass was incorporated into the soil immediately before flowering. The results show that at high soil salinity levels, BPG and SUG grew well, with the harvesting frequency of BPG being much higher than for SUG. Conversely, the growth of ALF and RHG was strongly inhibited by high soil salinity. Significant (P < 0.05) reduction of soil salinity levels (–3.2 dS/m) and related ionic concentrations, an increase of SOC (0.8% to 1.6%) and improvement of BD and HyCo were observed in BPG plots. The fast-growing nature of BPG in the hot climate of the experimental area resulted in harvests every three weeks and promoted the incorporation of high amounts of biomass to the soil and efficient soil salinity remediation. At moderately saline conditions, ALF also showed a great potential for salinity reclamation (–1.8 dS/m) and SOC accumulation. The cultivation of fast-growing annual crops proved an efficient and low-cost strategy for soil salinity mitigation and the reclamation of salinity-associated soil degradation in irrigation agriculture in Ethiopia.

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Wang, Zheng, Fei Zhang, Xianlong Zhang, Ngai Weng Chan, Hsiang-te Kung, Xiaohong Zhou et Yishan Wang. « Quantitative Evaluation of Spatial and Temporal Variation of Soil Salinization Risk Using GIS-Based Geostatistical Method ». Remote Sensing 12, n^o 15 (27 juillet 2020) : 2405. http://dx.doi.org/10.3390/rs12152405.

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Soil salinization is one of the environmental threats affecting the sustainable development of arid oases in the northwest of China. Thus, it is necessary to assess the risk of soil salinity and analyze spatial and temporal changes. The objective of this paper is to develop a temporal and spatial soil salinity risk assessment method based on an integrated scoring method by combining the advantages of remote sensing and GIS technology. Based on correlation coefficient analysis to determine the weights of risk evaluation factors, a comprehensive scoring system for the risk of salinity in the dry and wet seasons was constructed for the Ebinur Lake Wetland National Nature Reserve (ELWNNR), and the risk of spatial variation of soil salinity in the study area was analyzed in the dry and wet seasons. The results show the following: (1) The risk of soil salinity during the wet season is mainly influenced by the plant senescence reflectance index (PSRI), deep soil water content (D_wat), and the effect of shallow soil salinity (SH_sal). The risk of soil salinity during the dry season is mainly influenced by shallow soil salinity (SH_sal), land use and land cover change (LUCC), and deep soil moisture content (D_wat). (2) The wet season was found to have a high risk of salinization, which is mainly characterized by moderate, high, and very high risks. However, in the dry season, the risk of salinity is mainly characterized by low and moderate risk of salinity. (3) In the ELWNNR, as the wet season changes to dry season (from May to August), moderate-risk area in the wet season easily shifts to low risk and risk-free, and the area of high risk in the wet season easily shifts to moderate risk. In general, the overall change in salinity risk of the ELWNNR showed a significant relationship with changes in lake water volume, indicating that changes in water volume play an important role in the risk of soil salinity occurrence. Ideally, the quantitative analysis of salinity risk proposed in this study, which takes into account temporal and spatial variations, can help decision makers to propose more targeted soil management options.

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Rosicky, Mark A., Peter Slavich, Leigh A. Sullivan et Mike Hughes. « Surface and sub-surface salinity in and around acid sulfate soil scalds in the coastal floodplains of New South Wales, Australia ». Soil Research 44, n^o 1 (2006) : 17. http://dx.doi.org/10.1071/sr05027.

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Two-metre-deep soil profiles at 10 acid sulfate soil (ASS) scalds along the coast of New South Wales (NSW), Australia, were examined for salinity indicators. At 5 of the sites, permanently vegetated areas adjacent to the ASS-scalded land were also tested. Throughout the profiles, most sites had high soluble chloride (Cl−) concentrations (≤17 mg/g soil) and high soluble sulfate (SO42−) concentrations (≤17 mg/g soil). Very low Cl− : SO42− ratios (≤3) indicated active pyrite oxidation. Soil salinity (measured as electrical conductivity, EC) was extremely high in the top 2 m of most of the ASS scalds when related to the growth requirements of the typical introduced pasture species that were planted in these areas following drainage. This allows salinity, in addition to the extremely low pH of the surface soils, to contribute to land denudation, which can instigate or perpetuate pyrite oxidation and ASS-related land scalding. Although the sites had shallow watertables and soil-moisture content was high, the surface soil (top 0.10 m) of the scalds had consistently higher soluble Cl− and SO42− concentrations and EC than adjacent vegetated areas. All coastal ASS areas investigated, typically freshwater backswamps used for cattle grazing, were underlain by estuarine-derived sediments containing saline ground water. The results demonstrate that revegetation of ASS scalds must include investigation and management of salinity, in addition to acidity, within the soil profile and at the soil surface.

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Wang, Zhen Hua, Xu Rong Zheng, Cheng Xia Lei et Zhao Yang Li. « The Research on the Field Soil Salinity Environment Change with Different Drip Irrigation Years ». Advanced Materials Research 113-116 (juin 2010) : 792–96. http://dx.doi.org/10.4028/www.scientific.net/amr.113-116.792.

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With the increasion of the application years under-mulch drip irrigation, the field soil salinity environment change and its influence on the crops cause the concern. To choose the field close and continuously apply under-mulch drip irrigation about 2-14 and the cotton field 8 pieces in order to monitor soil salinity variation.The results initially show that :the soil of inner mulch with 0-20cm soil desalts,from40cm to 80cm accumulates salt; between the mulch bare land the soil salinity on the surface assembles,above the 60cm the soil salinity accumulates,below the 100cm the soil salinity is close to the inner mulch.The soil salinity content within four drip irrigation years is relatively high, is comparatively low over 6 drip irrigation years,the field salinity environment is relatively good.From 0 to 40cm the soil salinity content decreases with the drip irrigation years increases at the end of the growth process; from 60 to 100cm the accumulated salinity with the drip irrigation four years is highest.Suggest enlarging the salinity regulation dynamics within 6 drip irrigation years.

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Zhang, Jishi, Xilong Jiang, Yanfang Xue, Zongxin Li, Botao Yu, Liming Xu, Xingchen Lu, Qi Miao, Zitong Liu et Zhenling Cui. « Closing Yield Gaps through Soil Improvement for Maize Production in Coastal Saline Soil ». Agronomy 9, n^o 10 (23 septembre 2019) : 573. http://dx.doi.org/10.3390/agronomy9100573.

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As efforts to close crop production yield gaps increase, the need has emerged to identify cost-effective strategies to reduce yield losses through soil improvement. Maize (Zea mays L.) production in coastal saline soil is limited by high salinity and high pH, and a limited number of soil amendment options are available. We performed a field experiment in 2015 and 2016 to evaluate the ability of combined flue gas desulfurization gypsum and furfural residue application (CA) to reduce the maize yield gap and improve soil properties. We carried out the same amendment treatments (CA and no amendment as a control) under moderate (electrical conductivity (EC1:1) ≈ 4 dS m−1) and high (EC1:1 ≈ 6 dS m−1) salinity levels. Averaged over all salinity levels and years, maize yields increased from 32.6% of yield potential in the control to 44.2% with the CA treatments. Post-harvest CA treatment increased the calcium (Ca2+) and soil organic carbon (SOC) contents while decreasing the sodium (Na+) content and pH in the upper soil layer. Corresponding nitrogen, phosphorus, potassium, calcium, and magnesium accumulations in maize were significantly increased, and Na accumulation was decreased in the CA group compared with the control. The economic return associated with CA treatment increased by 215 $ ha−1 at the high salinity level compared with the control, but decreased at the moderate salinity level because of the minor increase in yield. The results of this study provide insight into the reduction of yield gaps by addressing soil constraints.

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Nielsen, Anne L., Kenneth O. Spence, Jamie Nakatani et Edwin E. Lewis. « Effect of soil salinity on entomopathogenic nematode survival and behaviour ». Nematology 13, n^o 7 (2011) : 859–67. http://dx.doi.org/10.1163/138855411x562254.

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Abstract Soil salinity, measured as electroconductivity (dS m–1), is a major problem in crop production, including areas where entomopathogenic nematodes (EPN) are applied as biological control agents. EPN species, primarily Heterorhabditis, have been isolated from coastal areas and agricultural soils with high salinity (> 4.0 dS m–1). Given the aqueous nature of their environment, soil salinity may play an important role in EPN movement and host finding. We assessed the survival of Steinernema riobrave, S. glaseri, Heterorhabditis indica, H. sonorensis and H. bacteriophora exposed to saline soils within the range found in agricultural soils. Survival and infectivity were generally unaffected by salinities ranging from 0 to 50 dS m–1 (50 dS m–1 is similar to the salinity of seawater). Salinity had been shown to negatively impact foraging in S. riobrave so additional experiments analysing the behaviour and attraction to host cues by S. riobrave and H. indica were conducted. Agar-based behavioural assays revealed species-specific responses to salinity. At the higher salinity levels (30 and 50 dS m–1) movement of H. indica decreased, the path taken was more circuitous and individuals did not move toward a host. There was a strong antagonistic effect on H. indica motility and host-finding behaviour. No significant differences were observed for S. riobrave exposed to any of these salinity levels. However, under simulated field conditions, high saline conditions (30 and 50 dS m–1) reduced the distance both H. indica and S. riobrave travelled toward a host. Both species are used for biological control of weevil pests in orchards where salinities have been recorded up to 20 dS m–1. Field efficacy of EPN applied for biological control in saline soils may be improved by timing applications to avoid late season build-up of salts in irrigated crops and applying the appropriate EPN species.

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Khamidov, Mukhamadkhan, Javlonbek Ishchanov, Ahmad Hamidov, Cenk Donmez et Kakhramon Djumaboev. « Assessment of Soil Salinity Changes under the Climate Change in the Khorezm Region, Uzbekistan ». International Journal of Environmental Research and Public Health 19, n^o 14 (20 juillet 2022) : 8794. http://dx.doi.org/10.3390/ijerph19148794.

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Soil salinity negatively affects plant growth and leads to soil degradation. Saline lands result in low agricultural productivity, affecting the well-being of farmers and the economic situation in the region. The prediction of soil salinization dynamics plays a crucial role in sustainable development of agricultural regions, in preserving the ecosystems, and in improving irrigation management practices. Accurate information through monitoring and evaluating the changes in soil salinity is essential for the development of strategies for agriculture productivity and efficient soil management. As part of an ex-ante analysis, we presented a comprehensive statistical framework for predicting soil salinity dynamics using the Homogeneity test and linear regression model. The framework was operationalized in the context of the Khorezm region of Uzbekistan, which suffers from high levels of soil salinity. The soil salinity trends and levels were projected under the impact of climate change from 2021 to 2050 and 2051 to 2100. The results show that the slightly saline soils would generally decrease (from 55.4% in 2050 to 52.4% by 2100 based on the homogeneity test; from 55.9% in 2050 to 54.5% by 2100 according to the linear regression model), but moderately saline soils would increase (from 31.2% in 2050 to 32.5% by 2100 based on the homogeneity test; from 31.2% in 2050 to 32.4% by 2100 according to the linear regression model). Moreover, highly saline soils would increase (from 13.4% in 2050 to 15.1% by 2100 based on the homogeneity test; from 12.9% in 2050 to 13.1% by 2100 according to the linear regression model). The results of this study provide an understanding that soil salinity depends on climate change and help the government to better plan future management strategies for the region.

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Sibbett, G. Steven. « Managing High pH, Calcareous, Saline, and Sodic Soils of the Western Pecan-growing Region ». HortTechnology 5, n^o 3 (juillet 1995) : 222–25. http://dx.doi.org/10.21273/horttech.5.3.222.

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Pecan [Carya illinoinensis (Wangenh. K. Koch)] soils in the arid western United States are characteristically high in pH, calcareous, and often saline or sodic. Economic production, when trees are grown in such soils, requires that growers pay particular attention to managing soil chemistry to avoid nutrient deficiencies, toxicities, or water deficits due to soil structural deterioration. Soil-applied acidulents, calcium-containing compounds, and water management are used by growers to manage high pH problems, sodic soil conditions, and salinity.

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Lu, Li, Sheng Li, Yuan Gao, Yanyan Ge et Yun Zhang. « Analysis of the Characteristics and Cause Analysis of Soil Salt Space Based on the Basin Scale ». Applied Sciences 12, n^o 18 (8 septembre 2022) : 9022. http://dx.doi.org/10.3390/app12189022.

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The analysis of water-soluble salts in the soil is an important basic work for the development and research of the salinity monitoring and salinization control of saline soils, aiming at the complexity of the development of soil salinization in oases in arid and semi-arid areas. Based on the regionalization theory, GPS positioning technology was adopted in this paper to conduct fixed point sampling of the Weigan River Basin oasis from April to May 2020. Soil sampling levels were between 0 m and 0.25 m, between 1 m and 2 m, and between 2 m and 3 m, respectively, and soil physical and chemical properties were analyzed and tested from May to June 2022. The spatial variability of soil salinity at different depths in the Weigan River Basin oasis was quantitatively studied by GIS and geostatistics, and the results show that: (1) the soil salinity of each layer in the Weigan River Basin oasis was generally high, with an average value of 1.27%, 0.87%, and 0.79%, respectively, and a variation coefficient between 1.023 and 1.265, showing strong variability. (2) A reasonable number of soil sampling should be based on the 95% confidence level and 20% relative error. Therefore, the number of soil samples in the corresponding layers should not be less than 89, 70, and 91. (3) Optimal fitting models of soil salinity at the layers between 0 m and 0.25 m and between 1 m and 2 m were both spherical models, while the optimal fitting model of soil salinity at the layer between 2 m and 3 m was an exponential model. Soil salinity at different depths is affected by random factors and structural factors. Soil salinity at the layer between 0 m and 0.25 m showed moderate spatial correlation, while soil salinity at the layers between 1 m and 2 m and between 2 m and 3 m showed strong spatial correlation. (4) Three layers of soil salinity had obvious anisotropy, and the maximum variation direction was northwest–southeast. The nested model can overcome the influence of directionality on the fitting of soil salinity variation function in the layer between 0 m and 0.25 m and improve the spatial interpolation accuracy. (5) In terms of spatial pattern, the area of high soil salinity was located along the Tarim River and at the edge of oasis (i.e., desert–oasis ecotone). On the whole, the salinity shows a gradual increasing trend from the inner part of the oasis (i.e., cultivation area) to the edge of the oasis, and from the northwest to the southeast. (6) The spatial distribution pattern of soil salinity in the study area was mainly affected by the differences in topography, groundwater level, and water quality, while agricultural activities intensified the formation of the distribution pattern, reflecting the complexity of the development of soil physical and chemical properties in arid and semi-arid areas. This study provided a reference for the improvement, management, and rational utilization of saline soil in the Weigan River Basin oasis.

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Kida, Morimaru, Mitsutoshi Tomotsune, Yasuo Iimura, Kazutoshi Kinjo, Toshiyuki Ohtsuka et Nobuhide Fujitake. « High salinity leads to accumulation of soil organic carbon in mangrove soil ». Chemosphere 177 (juin 2017) : 51–55. http://dx.doi.org/10.1016/j.chemosphere.2017.02.074.

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Paz, Maria Catarina, Mohammad Farzamian, Ana Marta Paz, Nádia Luísa Castanheira, Maria Conceição Gonçalves et Fernando Monteiro Santos. « Assessing soil salinity dynamics using time-lapse electromagnetic conductivity imaging ». SOIL 6, n^o 2 (12 octobre 2020) : 499–511. http://dx.doi.org/10.5194/soil-6-499-2020.

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Abstract. Lezíria Grande de Vila Franca de Xira, located in Portugal, is an important agricultural system where soil faces the risk of salinization due to climate change, as the level and salinity of groundwater are likely to increase as a result of the rise of the sea water level and consequently of the estuary. These changes can also affect the salinity of the irrigation water which is collected upstream of the estuary. Soil salinity can be assessed over large areas by the following rationale: (1) use of electromagnetic induction (EMI) to measure the soil apparent electrical conductivity (ECa, mS m−1); (2) inversion of ECa to obtain electromagnetic conductivity imaging (EMCI) which provides the spatial distribution of the soil electrical conductivity (σ, mS m−1); (3) calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (ECe, dS m−1), used as a proxy for soil salinity; and (4) conversion of EMCI into salinity cross sections using the obtained calibration equation. In this study, EMI surveys and soil sampling were carried out between May 2017 and October 2018 at four locations with different salinity levels across the study area of Lezíria de Vila Franca. A previously developed regional calibration was used for predicting ECe from EMCI. Using time-lapse EMCI data, this study aims (1) to evaluate the ability of the regional calibration to predict soil salinity and (2) to perform a preliminary qualitative analysis of soil salinity dynamics in the study area. The validation analysis showed that ECe was predicted with a root mean square error (RMSE) of 3.14 dS m−1 in a range of 52.35 dS m−1, slightly overestimated (−1.23 dS m−1), with a strong Lin's concordance correlation coefficient (CCC) of 0.94 and high linearity between measured and predicted data (R2=0.88). It was also observed that the prediction ability of the regional calibration is more influenced by spatial variability of data than temporal variability of data. Soil salinity cross sections were generated for each date and location of data collection, revealing qualitative salinity fluctuations related to the input of salts and water either through irrigation, precipitation, or level and salinity of groundwater. Time-lapse EMCI is developing into a valid methodology for evaluating the risk of soil salinization, so it can further support the evaluation and adoption of proper agricultural management strategies, especially in irrigated areas, where continuous monitoring of soil salinity dynamics is required.

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Elhag, Mohamed. « Evaluation of Different Soil Salinity Mapping Using Remote Sensing Techniques in Arid Ecosystems, Saudi Arabia ». Journal of Sensors 2016 (2016) : 1–8. http://dx.doi.org/10.1155/2016/7596175.

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Land covers in Saudi Arabia are generally described as salty soils with sand dunes and sand sheets. Waterlogging and higher soil salinity are major challenges to sustaining agricultural practices in Saudi Arabia principally within closed drainage basins. Agricultural practices in Saudi Arabia were flourishing in the last two decades. The newly reclaimed lands were added annually and distributed all over the country. Irrigation techniques are mostly modernized to fulfill water saving strategies. Nevertheless, water resources in Saudi Arabia are under stress and groundwater levels are depleted rapidly due to heavy abstraction that may exceed crop water requirements in most of the cases due to high evaporation rates. The excess use of irrigational water leads to severe soil salinity problems. Applications of remote sensing technique in agricultural practices became widely distinctive and cover multidisciplinary principal interests on both local and regional levels. The most important remote sensing applications in agricultural practices are vegetation indices which are related to vegetation and water especially in an arid environment. Soil salinity mapping in an arid ecosystem using remote sensing data is a demanding task. Several soil salinity indices were implemented and evaluated to detect soil salinity effectively and quantitatively. Thematic maps of soil salinity were satisfactorily produced and assessed.

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Minh, Warneke, Bissett, Cao, Macdonald et Strong. « Quantifying Gas Emissions and Denitrifying Genes in a Salt-Affected Soil ». Proceedings 36, n^o 1 (30 décembre 2019) : 23. http://dx.doi.org/10.3390/proceedings2019036023.

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Salinity effects on microbial community relative to greenhouse gas emissions are not well understood in salt-affected soils. A better understanding of this interaction would be useful for agricultural practices to reduce nitrogen gas losses and manage environmental pollution. We hypothesized that elevated salinity would increase the abundance of denitrifier genes resulting in a low rate of gas emissions. Objectives of this study were to measure induced-soil greenhouse gas emissions and to quantify denitrifying genes in a salt-affected soil over a 3-week incubation period. This incubation study was conducted by submerging field-moist samples of an acid sulphate soil in different saline solutions. A quantitative polymerase chain reaction (qPCR) was used to quantify the abundance of resident bacterial denitrification genes in the salt-affected soil. It was found that increased salinity caused a decrease in both flux and cumulative emission of N2O from the incubated soil, relative to fresh water. Soil respiration was significantly reduced in salinity treatments compared to the treatment of distilled water. The study results showed that elevated salinity increased the denitrifying genes in the incubated acid sulfate soil. The abundance of the nir genes was usually high between the first and second week of incubation, while number copies of the nosZ gene were significantly low at those times. The study concludes that salinity controls the biological aspects of denitrification leading to a reduction of greenhouse gas emissions. Findings from this investigation extend our knowledge about the underlying molecular ecological mechanisms of denitrification that manage nitrogen cycling in salt-affected soils.

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Ado, Maman Nassirou, Didier Michot, Yadji Guero, Zahra Thomas et Christian Walter. « Monitoring and Modeling of Saline-Sodic Vertisol Reclamation by Echinochloa stagnina ». Soil Systems 6, n^o 1 (4 janvier 2022) : 4. http://dx.doi.org/10.3390/soilsystems6010004.

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Soil salinity due to irrigation is a major constraint to agriculture, particularly in arid and semi-arid zones, due to water scarcity and high evaporation rates. Reducing salinity is a fundamental objective for protecting the soil and supporting agricultural production. The present study aimed to empirically measure and simulate with a model, the reduction in soil salinity in a Vertisol by the cultivation and irrigation of Echinochloa stagnina. Laboratory soil column experiments were conducted to test three treatments: (i) ponded bare soil without crops, (ii) ponded soil cultivated with E. stagnina in two successive cropping seasons and (iii) ponded soil permanently cultivated with E. stagnina with a staggered harvest. After 11 months of E. stagnina growth, the electrical conductivity of soil saturated paste (ECe) decreased by 79–88% in the topsoil layer (0–8 cm) in both soils cultivated with E. stagnina and in bare soil. In contrast, in the deepest soil layer (18–25 cm), the ECe decreased more in soil cultivated with E. stagnina (41–83%) than in bare soil (32–58%). Salt stocks, which were initially similar in the columns, decreased more in soil cultivated with E. stagnina (65–87%) than in bare soil (34–45%). The simulation model Hydrus-1D was used to predict the general trends in soil salinity and compare them to measurements. Both the measurements and model predictions highlighted the contrast between the two cropping seasons: soil salinity decreased slowly during the first cropping season and rapidly during the second cropping season following the intercropping season. Our results also suggested that planting E. stagnina was a promising option for controlling the salinity of saline-sodic Vertisols.

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Moussa, Issaka, Christian Walter, Didier Michot, Issifou Adam Boukary, Hervé Nicolas, Pascal Pichelin et Yadji Guéro. « Soil Salinity Assessment in Irrigated Paddy Fields of the Niger Valley Using a Four-Year Time Series of Sentinel-2 Satellite Images ». Remote Sensing 12, n^o 20 (16 octobre 2020) : 3399. http://dx.doi.org/10.3390/rs12203399.

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Salinization is a major soil degradation threat in irrigated systems worldwide. Irrigated systems in the Niger River basin are also affected by salinity, but its spatial distribution and intensity are not currently known. The aim of this study was to develop a method to detect salt-affected soils in irrigated systems. Two complementary approaches were tested: salinity assessment of bare soils using a salinity index (SI) and monitoring of indirect effects of salinity on rice growth using temporal series of a vegetation index (NDVI). The study area was located south of Niamey (Niger) in two irrigated systems of rice paddy fields that cover 6.5 km2. We used remote-sensing and ground-truth data to relate vegetation behavior and reflectance to soil characteristics. We explored all existing Sentinel-2 images from January 2016 to December 2019 and selected cloud-free images on 157 dates that covered eight successive rice-growing seasons. In the dry season of 2019, we also sampled 44 rice fields, collecting 147 biomass samples and 180 topsoil samples from January to June. For each field and growing season, time-integrated NDVI (TI-NDVI) was estimated, and the SI was calculated for dates on which bare soil conditions (NDVI < 0.21) prevailed. Results showed that since there were few periods of bare soil, SI could not differentiate salinity classes. In contrast, the high temporal resolution of Sentinel-2 images enabled us to describe rice-growing conditions over time. In 2019, TI-NDVI and crop yields were strongly correlated (r = 0.77 with total biomass yield and 0.82 with grain yield), while soil electrical conductivity was negatively correlated with both TI-NDVI (r = −0.38) and crop yield (r = −0.23 with total biomass and r = −0.29 with grain yield). Considering the TI-NDVI data from 2016–2019, principal component analysis followed by ascending hierarchical classification identified a typology of five clusters with different patterns of TI-NDVI during the eight growing seasons. When applied to the entire study area, this classification clearly identified the extreme classes (i.e., areas with high or no salinity). Other classes with low TI-NDVI (i.e., during dry seasons) may be related to areas with moderate or seasonal soil salinity. Finally, the high temporal resolution of Sentinel-2 images enabled us to detect stresses on vegetation that occurred repeatedly over the growing seasons, which may be good indicators of soil constraints due to salinity in the context of the irrigated paddy systems of Niger. Further research will validate the ability of the method developed to detect moderate soil salinity constraints over large areas.

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Abedi-Koupai, Jahangir, Mojtaba Khoshravesh et Mohammad Ebrahim Zanganeh. « Distribution of moisture and salinity under deficit irrigation and irrigation water salinity in an alternative trickle irrigation system of tape ». Water Supply 13, n^o 2 (1 mars 2013) : 394–402. http://dx.doi.org/10.2166/ws.2013.004.

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This study was performed to investigate the horizontal and vertical distribution of soil moisture and salinity using an alternative trickle irrigation system of drip tape. Four main treatments consisting of 100, 80, 70, and 60% of the plants’ water requirements and three sub-treatments of 2.1, 4.6, and 10.2 dS/m, were conducted. Following irrigation, the soil moisture and salinity distribution around the emitters were measured every 24 h. The results showed that the accumulation of salts in the soil reduced the evaporation from the soil surface in treatments with high salinity. Therefore, in treatments with a low plant water requirement and high salinity levels, the volume of water in the soil is greater than in treatments with a high plant water requirement and low salinity levels. Although the crop yield is reduced with deficit irrigation, the saved water can be used to increase the area under cultivation, leading to increases in the overall crop yield.

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Hien, Le Thi Thu, Anne Gobin, Duong Thi Lim, Dang Tran Quan, Nguyen Thi Hue, Nguyen Ngoc Thang, Nguyen Thanh Binh, Vu Thi Kim Dung et Pham Ha Linh. « Soil Moisture Influence on the FTIR Spectrum of Salt-Affected Soils ». Remote Sensing 14, n^o 10 (15 mai 2022) : 2380. http://dx.doi.org/10.3390/rs14102380.

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Soil salinity has a major impact on agricultural production. In a changing climate with rising sea-levels, low-lying coastal areas are increasingly inundated whereby saltwater gradually contaminates the soil. Drought prone areas may suffer from salinity due to high evapotranspiration rates in combination with the use of saline irrigation water. Salinity is difficult to monitor because soil moisture affects the soil’s spectral signature. We conducted Fourier-transform infrared spectroscopy on alluvial and sandy soil samples in the coastal estuary of the Red River Delta. The soils are contaminated with NaCl, Na2CO3 and Na2SO4 salts. In an experiment of salt contamination, we established that three ranges of the spectrum were strongly influenced by both salt and moisture content in the soil, at wavenumbers 3200–3400 cm−1 (2.9–3.1 µm); 1600–1700 cm−1 (5.9–6.3 µm); 900–1100 cm−1 (9.1–11.1 µm). The Na2CO3 contaminated soil and the spectral value had a linear relationship between wavelengths 6.9 and 7.4 µm. At wavelength 6.99 µm, there was no relationship between absorbance and soil moisture, but the absorbance was proportional to the salt content (R2 = 0.85; RMSE = 0.68 g) and electrical conductivity (R2 = 0.50; RMSE = 3.8 dS/m). The relationship between soil moisture and spectral absorbance value was high at wavelengths below 6.7 µm, resulting in a quadratic relation between soil moisture and absorbance at wavelength 6.13 µm (R2 = 0.80; RMSE = 5.2%). The spectral signatures and equations might be useful for mapping salt-affected soils, particularly in difficult to access locations. Technological advances in thermal satellite sensors may offer possibilities for monitoring soil salinity.

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Wang, Jie, Weikun Wang, Yuehong Hu, Songni Tian et Dongwei Liu. « Soil Moisture and Salinity Inversion Based on New Remote Sensing Index and Neural Network at a Salina-Alkaline Wetland ». Water 13, n^o 19 (6 octobre 2021) : 2762. http://dx.doi.org/10.3390/w13192762.

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In arid and semi-arid regions, soil moisture and salinity are important elements to control regional ecology and climate, vegetation growth and land function. Soil moisture and salt content are more important in arid wetlands. The Ebinur Lake wetland is an important part of the ecological barrier of Junggar Basin in Xinjiang, China. The Ebinur Lake Basin is a representative area of the arid climate and ecological degradation in central Asia. It is of great significance to study the spatial distribution of soil moisture and salinity and its causes for land and wetland ecological restoration in the Ebinur Lake Basin. Based on the field measurement and Landsat 8 satellite data, a variety of remote sensing indexes related to soil moisture and salinity were tested and compared, and the prediction models of soil moisture and salinity were established, and the accuracy of the models was assessed. Among them, the salinity indexes D1 and D2 were the latest ones that we proposed according to the research area and data. The distribution maps of soil moisture and salinity in the Ebinur Lake Basin were retrieved from remote sensing data, and the correlation analysis between soil moisture and salinity was performed. Among several soil moisture and salinity prediction indexes, the normalized moisture index NDWI had the highest correlation with soil moisture, and the salinity index D2 had the highest correlation with soil salinity, reaching 0.600 and 0.637, respectively. The accuracy of the BP neural network model for estimating soil salinity was higher than the one of other models; R2 = 0.624, RMSE = 0.083 S/m. The effect of the cubic function prediction model for estimating soil moisture was also higher than that of the BP neural network, support vector machine and other models; R2 = 0.538, RMSE = 0.230. The regularity of soil moisture and salinity changes seemed to be consistent, the correlation degree was 0.817, and the synchronous change degree was higher. The soil salinity in the Ebinur Lake Basin was generally low in the surrounding area, high in the middle area, high in the lake area and low in the vegetation coverage area. The soil moisture in the Ebinur Lake Basin slightly decreased outward with the Ebinur Lake as the center and was higher in the west and lower in the east. However, the spatial distribution of soil moisture had a higher mutation rate and stronger heterogeneity than that of soil salinity.

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Tavakkoli, Ehsan, Pichu Rengasamy et Glenn K. McDonald. « The response of barley to salinity stress differs between hydroponic and soil systems ». Functional Plant Biology 37, n^o 7 (2010) : 621. http://dx.doi.org/10.1071/fp09202.

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Many studies on salinity stress assume that responses in hydroponics mimic those in soil. However, interactions between the soil solution and the soil matrix can affect responses to salinity stress. This study compared responses to salinity in hydroponics and soil, using two varieties of barley (Hordeum vulgare L.). The responses to salinity caused by high concentrations of Na+ and Cl– were compared to assess any consistent differences between hydroponics and soil associated with a cation and an anion that contribute to salinity stress. Concentrated nutrient solutions were also used to assess the effects of osmotic stress. The effects of salinity differed between the hydroponic and soil systems. Differences between barley cultivars in growth, tissue moisture content and ionic composition were not apparent in hydroponics, whereas significant differences occurred in soil. Growth reductions were greater under hydroponics than in soil at similar electrical conductivity values, and the uptake of Na+ and Cl– was also greater. The relative importance of ion exclusion and osmotic stress varied. In soil, ion exclusion tended to be more important at low to moderate levels of stress (EC at field capacity up to 10 dS m–1) but osmotic stress became more important at higher stress levels. High external concentrations of Cl– had similar adverse effects as high concentrations of Na+, suggesting that Cl– toxicity may reduce growth. Fundamental differences in salinity responses appeared between soil and solution culture, and the importance of the different mechanisms of damage varies according to the severity and duration of the salt stress.

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Levy, Joseph S., Andrew G. Fountain, Michael N. Gooseff, J. E. Barrett, Robert Vantreese, Kathy A. Welch, W. Berry Lyons, Uffe N. Nielsen et Diana H. Wall. « Water track modification of soil ecosystems in the Lake Hoare basin, Taylor Valley, Antarctica ». Antarctic Science 26, n^o 2 (10 juillet 2013) : 153–62. http://dx.doi.org/10.1017/s095410201300045x.

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AbstractWater tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter within the water track relative to soils outside the water track, and reducing soil phosphate, soil pH, and the population of nematodes and other invertebrates in water track soils relative to off track soils. These results suggest that water tracks are distinct and extreme ecological zones in Taylor Valley that provide long-range (kilometre to multi- kilometre) structure to Antarctic hillslope ecosystems through physical control on soil moisture and solute content. Contrary to expectations, these high soil-moisture sites are not hotspots for faunal biological activity because high soil salinity makes them suitable habitats for only the most halo-tolerant organisms.

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Anwari, Gulaqa Aqa, Ajmal Mandozai et Jin Feng. « Effects of Biochar Amendment on Soil Problems and Improving Rice Production under Salinity Conditions ». Advanced Journal of Graduate Research 7, n^o 1 (28 octobre 2019) : 45–63. http://dx.doi.org/10.21467/ajgr.7.1.45-63.

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Soil with poor physio-chemical and biological properties prevent plant growth. These poor characteristics may be due to soil creation processes, but also include largely inappropriate agricultural practices and/or anthropogenic pollution. During the last 4 decades, the world has lost one-third of its cropland due to pollution and erosion. Therefore, a series of operations is required to improve and recover the soil. Biochar is a new multifunctional carbon material extensively used as a modifier to improve soil quality and crop production. Previous studies have discussed the properties of biochar with varying soil pollutants and their effects on soil productivity and carbon sequestration. Comparatively, little attention has been paid to the effects of biochar application on rice growth in the problem of soils, especially in the saline-sodic soils. A comprehensive review of the literature with a high focusing on the effects of biochar application on problem soils and rice-growing under salinity conditions is needed. The present review gives an overview of the soil's problem, biochar amendment effects on physicochemical properties of soil, and how the biochar amendment could interact in soil microbes and root with remediation under salinity conditions for improving rice productivity. The findings of this review showed that biochar application can improve soil quality, reduce soil's problem and increase rice production under salinity conditions. It is anticipated that further researches on the biochar amendment will increase our understanding of the interactions of biochar with soil components, accelerate our attempts on soil remediation, and improve rice production under salinity conditions.

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Yang, Yuhui, Dongwei Li, Weixiong Huang, Xinguo Zhou, Zhaoyang Li, Xiaomei Dong et Xingpeng Wang. « Effects of Subsurface Drainage on Soil Salinity and Groundwater Table in Drip Irrigated Cotton Fields in Oasis Regions of Tarim Basin ». Agriculture 12, n^o 12 (16 décembre 2022) : 2167. http://dx.doi.org/10.3390/agriculture12122167.

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As one global issue, soil salinization has caused soil degradation, thus affecting the sustainable development of irrigated agriculture. A two-year study was conducted in 2018 and 2019 to identify the effects of subsurface drainage spacing on soil salinity and groundwater level, the latter of which is in a high-water table in drip irrigation cotton fields in the Tarim Basin oasis in southern Xinjiang, China. Three subsurface drainage treatments, with a drain spacing of 10 m (W10), 20 m (W20), and 30 m (W30), respectively, and a drainage-absent treatment (CK), are tested. With CK, soil salinity in the 0–60 cm layer was accumulated within a year. In contrast, the subsurface drainage reduced the soil salinity at a leaching rate of 10–25%. When decreasing the drain spacing, it was found that the soil desalination rate increased significantly (p < 0.05) with good repeatability. Experimental results showed that the fitting equation of the soil salinity leaching curve could accurately describe the soil salinity leaching pattern of drip irrigation, and thus could be further used to inversely determine the theoretical drip irrigation leaching quota for those soils with different salinity degrees. As such, subsurface drainage could effectively control the groundwater table. Compared with CK, subsurface drainage deepened the groundwater table and mitigated the fluctuation of the groundwater level. These effects were strengthened by reducing the drain spacing. Correspondingly, the influence of the fluctuation of the groundwater table was reduced.

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JANZEN, H. H., et C. CHANG. « CATION NUTRITION OF BARLEY AS INFLUENCED BY SOIL SOLUTION COMPOSITION IN A SALINE SOIL ». Canadian Journal of Soil Science 67, n^o 3 (1 août 1987) : 619–29. http://dx.doi.org/10.4141/cjss87-058.

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Identification of nutritional disorders in crops growing on saline soils may facilitate the development of breeding or agronomic practices that improve yields in saline areas. An investigation was conducted under controlled environment conditions to identify possible cation deficiencies in barley (Hordeum vulgare 'Gait') grown under sulfate-dominated salinity stress. Soil was artificially salinized to produce a factorial of five salinity levels (ranging from approximately 6.5 to 17.5 dS m−1) and five salt types containing various ratios of Na:Mg:Ca. A control treatment (3.1 dS m−1) was also included. Barley was grown for 75 d and harvested for analysis of dry matter yield and tissue composition. Yield response of barley to salinity stress was not differentially affected by the type of salt used in salinization. Concentrations of sodium and magnesium in the plant tissue were generally increased by salinity stress, but these accumulations did not restrict yield since no consistent relationship was found between the concentrations of these cations and barley yield. Potassium concentration in the plants was inversely related to level of soil salinity, apparently because of an antagonistic effect of sodium, but was not consistently related to barley dry matter yield. Calcium uptake was also suppressed by soil salinity. In contrast to the results observed for other cations, a very strong relationship indicative of a yield response curve was observed between yield and calcium concentration in the plant tissue, particularly when the latter was expressed as a ratio of total cation concentration (R2 = 0.94). Furthermore, calcium concentration in the plant tissue and estimated calcium activity in the soil solution in highly salinized treatments were well below those considered adequate. These results suggest that calcium deficiency may have played an important role in restricting yield under salinity stress. The apparent calcium deficiency induced by salinity stress was attributed to reduced activity of calcium in the soil solution because of precipitation with sulfate and high ionic strength. Key words: Calcium, magnesium, potassium, sodium, salinity

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Sinha, D. D., A. N. Singh et U. S. Singh. « Site Suitability Analysis for Dissemination of Salt-tolerant Rice Varieties in Southern Bangladesh ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (28 novembre 2014) : 961–66. http://dx.doi.org/10.5194/isprsarchives-xl-8-961-2014.

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Bangladesh is a country of 14.4 million ha geographical area and has a population density of more than 1100 persons per sq. km. Rice is the staple food crop, growing on about 72 % of the total cultivated land and continues to be the most important crop for food security of the country. A project "Sustainable Rice Seed Production and Delivery Systems for Southern Bangladesh" has been executed by the International Rice Research Institute (IRRI) in twenty southern districts of Bangladesh. These districts grow rice in about 2.9 million ha out of the country’s total rice area of 11.3 million ha. The project aims at contributing to the Government of Bangladesh’s efforts in improving national and household food security through enhanced and sustained productivity by using salinity-, submergence- and drought- tolerant and high yielding rice varieties. Out of the 20 project districts, 12 coastal districts are affected by the problem of soil salinity. The salt-affected area in Bangladesh has increased from about 0.83 million ha in 1973 to 1.02 million ha in 2000, and 1.05 million ha in 2009 due to the influence of cyclonic storms like "Sidr", "Laila" and others, leading to salt water intrusion in croplands. Three salinity-tolerant rice varieties have recently been bred by IRRI and field tested and released by the Bangladesh Rice Research Institute (BRRI) and Bangladesh Institute of Nuclear Agriculture (BINA). These varieties are BRRI dhan- 47 and Bina dhan-8 and - 10. However, they can tolerate soil salinity level up to EC 8−10 dSm−1, whereas the EC of soils in several areas are much higher. Therefore, a large scale dissemination of these varieties can be done only when a site suitability analysis of the area is carried out. The present study was taken up with the objective of preparing the site suitability of the salt-tolerant varieties for the salinity-affected districts of southern Bangladesh. Soil salinity map prepared by Soil Resources Development Institute of Bangladesh shows five classes of salinity. viz., non-saline with some very slight saline soil, very slightly saline with some slight saline soil, slightly saline with some moderately saline soil, strongly saline with some moderately saline soil, and very strongly saline with some strongly saline soil. The soil EC level of different classes range from 2 dSm−1 to >16 dSm−1. The soil map was geo-referenced and digitized using Arc GIS. Salinity tolerance characteristics of the rice varieties were matched with the soil characteristics shown on the map. Three suitability classes were made; soils suitable for salt-tolerant varieties, not suitable for salt-tolerant varieties due to high soil salinity, and suitable for other high yielding varieties due to slight salinity. The mauza (smallest revenue unit) boundary provided by the Bangladesh Agriculture Research Council was also geo-referenced and digitized in the same projection. Overlaying and intersecting the mauza boundary on the soil suitability map provided the suitable and not suitable mauza. A total of 4070 mauzas in the 12 salinity-affected districts were listed and maps showing suitability of mauza prepared. About 0.6 million ha out of total 0.87 million ha salinity affected area were found suitable for growing the salinity-tolerant BRRI dhan-47, Bina dhan-8 and -10 in these districts. The maps and other generated information have helped the Dept. of Agriculture Extension (DAE) of Bangladesh in large scale dissemination of seeds of the salinity-tolerant rice varieties in different districts during the past two years.

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Beke, G. J., et K. M. Volkmar. « Mineral composition of flax (Linum usitatissimum L.) and safflower (Carthamus tinctorius L.) on a saline soil high in sulfate salts ». Canadian Journal of Plant Science 75, n^o 2 (1 avril 1995) : 399–404. http://dx.doi.org/10.4141/cjps95-067.

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Little information is available on the ion control mechanisms of safflower and flax under the sulfate-salinity conditions typical of the Canadian prairies region. Chemical constituents of Saffire safflower and Andro flax were investigated in the field to evaluate their response to soil salinity. Mean Ca:Mg and K:Na ratios of plant tops, yield, and seed oil-content were lower on saline soil than on nonsaline soil. On saline soil, the total cation content of flax tops decreased less rapidly with age than that of safflower, mainly due to high uptake of Na+ by flax. The pattern of ion regulation in safflower (high K:Na ratio) typifies a more "tolerant" response to salinity than that in flax. Key words: Mineral composition, oilseed crops, saline field soil, Na2SO4 salinity, Na+ uptake, K:Na ratio

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Joshi, Abhishek, Vishnu D. Rajput, Krishan K. Verma, Tatiana Minkina, Karen Ghazaryan et Jaya Arora. « Potential of Suaeda nudiflora and Suaeda fruticosa to Adapt to High Salinity Conditions ». Horticulturae 9, n^o 1 (6 janvier 2023) : 74. http://dx.doi.org/10.3390/horticulturae9010074.

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The deposition of salts in soil seems likely to become a significant barrier for plant development and growth. Halophytes that flourish in naturally saline habitats may sustain extreme salt levels by adopting different acclimatory traits. Insight into such acclimatory features can be useful for devising salt-resilient crops and the reclamation of saline soil. Therefore, salinity-induced responses were studied in two halophytes, i.e., Suaeda nudiflora and Suaeda fruticosa, at a high soil salinity level (ECe 65) to explore their possible tolerance mechanisms in their natural habitat. Samples of different tissues were collected from both Suaeda species for the determination of physio-biochemical attributes, i.e., ionic (Na+, K+, Ca2+, Cl−) content, osmo-protective compounds (proline, soluble sugars, soluble proteins), total phenolic content, and antioxidant components. Heavy metal composition and accumulation in soil and plant samples were also assessed, respectively. Fourier transform infrared spectroscopy (FTIR) analysis was conducted to explore cellular metabolite pools with respect to high salinity. The results showed that both species considerably adjusted the above-mentioned physio-biochemical attributes to resist high salinity, demonstrated by quantitative differences in their above-ground tissues. The FTIR profiles confirmed the plants’ differential responses in terms of variability in lipids, proteins, carbohydrates, and cell wall constituents. The high capacity for Na+ and Cl− accumulation and considerable bioaccumulation factor (BAF) values for metals, mainly Fe and Zn, validate the importance of both Suaeda species as phytodesalination plants and their potential use in the phytoremediation of salt- and metal-polluted soils.

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Xie, Wenping, Jingsong Yang, Rongjiang Yao et Xiangping Wang. « Spatial and Temporal Variability of Soil Salinity in the Yangtze River Estuary Using Electromagnetic Induction ». Remote Sensing 13, n^o 10 (11 mai 2021) : 1875. http://dx.doi.org/10.3390/rs13101875.

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Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.

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Peddinti, Srinivasa Rao, Jan W. Hopmans, Majdi Abou Najm et Isaya Kisekka. « Assessing Effects of Salinity on the Performance of a Low-Cost Wireless Soil Water Sensor ». Sensors 20, n^o 24 (9 décembre 2020) : 7041. http://dx.doi.org/10.3390/s20247041.

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Low-cost, accurate soil water sensors combined with wireless communication in an internet of things (IoT) framework can be harnessed to enhance the benefits of precision irrigation. However, the accuracy of low-cost sensors (e.g., based on resistivity or capacitance) can be affected by many factors, including salinity, temperature, and soil structure. Recent developments in wireless sensor networks offer new possibilities for field-scale monitoring of soil water content (SWC) at high spatiotemporal scales, but to install many sensors in the network, the cost of the sensors must be low, and the mechanism of operation needs to be robust, simple, and consume low energy for the technology to be practically relevant. This study evaluated the performance of a resistivity–capacitance-based wireless sensor (Sensoterra BV, 1018LE Amsterdam, Netherlands) under different salinity levels, temperature, and soil types in a laboratory. The sensors were evaluated in glass beads, Oso Flaco sand, Columbia loam, and Yolo clay loam soils. A nonlinear relationship was exhibited between the sensor measured resistance (Ω) and volumetric soil water content (θ). The Ω–θ relationship differed by soil type and was affected by soil solution salinity. The sensor was extremely sensitive at higher water contents with high uncertainty, and insensitive at low soil water content accompanied by low uncertainty. The soil solution salinity effects on the Ω–θ relationship were found to be reduced from sand to sandy loam to clay loam. In clay soils, surface electrical conductivity (ECs) of soil particles had a more dominant effect on sensor performance compared to the effect of solution electrical conductivity (ECw). The effect of temperature on sensor performance was minimal, but sensor-to-sensor variability was substantial. The relationship between bulk electrical conductivity (ECb) and volumetric soil water content was also characterized in this study. The results of this study reveal that if the sensor is properly calibrated, this low-cost wireless soil water sensor has the potential of improving soil water monitoring for precision irrigation and other applications at high spatiotemporal scales, due to the ease of integration into IoT frameworks.

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Bendixen, W. E., et B. R. Hanson. « Soil Moisture and Soil Salinity Distribution in Strawberry Beds ». HortScience 33, n^o 3 (juin 1998) : 538b—538. http://dx.doi.org/10.21273/hortsci.33.3.538b.

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Strawberries in the Santa Maria Valley are grown on beds 25.2 cm wide with four rows of strawberries and two lateral drip tapes. Previous strawberry production was on beds 15.7 cm wide with two rows of strawberries and one lateral drip tape. The two strawberry production systems were evaluated on several grower fields for water emission uniformity, soil moisture, and soil salinity. The salinity was evaluated for placement in the bed, type of salts, and nitrate concentration. At one side, the effect of banded slow-release nitrogen fertilizers as a source of nitrogen in addition to that applied through fertigation was investigated. Results showed that the EUs ranged between 80% and 96%, with an average of 89%. A variety of distributions were found for soil moisture, soil salinity, and soil nitrate, depending on the water and fertilizer management and time of sampling with respect to irrigation and fertigation. Distributions of soil moisture content made 3 to 4 days after an irrigation indicated excessive drying of the soil between irrigations. Distributions of soil salinity revealed high salt concentrations near the drip tape, where leaching was insufficient, and relatively low concentrations near the tape, where leaching was adequate. Nitrate concentrations in and below the rootzone were smaller where no slow-release fertilizers were used.

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Dong, Ruolin, et Xiaodong Na. « Quantitative Retrieval of Soil Salinity Using Landsat 8 OLI Imagery ». Applied Sciences 11, n^o 23 (24 novembre 2021) : 11145. http://dx.doi.org/10.3390/app112311145.

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Soil salinization is the main reason for declining soil quality and a reduction in agricultural productivity. We derive the spatial distribution of soil moisture from the temperature vegetation dryness index (TVDI) of Landsat TM-8 OLI images to analyze the effect of spatial heterogeneity of soil moisture on the retrieval accuracy of soil salinity. We establish five soil salinity inversion models for different soil moisture levels (drought levels) based on the canopy response salinity index (CRSI), normalized difference vegetation index (NDVI), and automatic water extraction index (AWEI) derived from Landsat TM-8 OLI images. The inversion accuracy of soil salinity is assessed using 42 field samples. The results show that the average accuracies of the five inversion models are higher than that of the traditional soil salinity inversion model of the entire study area. The proposed model underestimates soil salinity in high-moisture areas and overestimates it in drought areas. Therefore, inversion models of soil salinization should consider spatial differences in soil moisture to improve the inversion accuracy.

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Abd El-Hamed, Enas, S. Metwally, M. Matar et N. Yousef. « Impact of phosphorus fertilization in alleviating the adverse effects of salinity on wheat grown on different soil types ». Acta Agronomica Hungarica 60, n^o 3 (1 septembre 2012) : 265–81. http://dx.doi.org/10.1556/aagr.60.2012.3.9.

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Optimum fertilization management is an important technique to alleviate the adverse effects of salinity stress on plants. A pot experiment was conducted to evaluate the ameliorative role of inorganic phosphorus (P) and organic P sources on wheat grown under salt stress in three soil types deficient in available P. Wheat (Triticum aestivum L. cv. Shakha 93) was grown on alluvial, sandy and calcareous soils at salinity levels of 4, 8 and 12 dS/m of saturated paste extract (ECe) and supplied with a constant rate of 30 mg P2O5/kg soil as superphosphate (SP), cattle manure (CM) and a 1:1 mixture of SP and CM. The results revealed that plants grown on the sandy soil were more susceptible to the adverse effects of salinity than those planted on the alluvial one, especially at zero P. Plants grown on the calcareous soil were moderately affected. The varying soil type caused significant differences in the aboveground biomass and the uptake of N, K, P and Zn. It was obvious that P ameliorated wheat growth under salt stress, and this role was greater under moderate and high salinity. The increases in N, P, K and Zn uptake driven by P application were more conspicuous in the sandy and calcareous soils. The results also indicated that the combined application of inorganic and organic P sources surpassed that of either when applied alone on all soil types and salinity levels.

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