28 research outputs found

    Root Morphology and Rhizosphere Characteristics Are Related to Salt Tolerance of Suaeda salsa and Beta vulgaris L.

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    Halophytes are capable of resisting salinity, and their root system is the part in direct contact with the saline soil environment. The aim of this study was to compare the responses of root morphology and rhizosphere characteristics to salinity between a halophyte, Suaeda salsa (suaeda), and a glycophyte, Beta vulgaris L. (sugar beet). The soil salt content was set to four levels (0.7, 1.2, 1.7, and 2.7%) by NaCl-treated plants. We investigated the soil pH, EC, nutrients and soil, plant ion (Na+, Cl−, K+, and Mg2+) concentration to evaluate the rhizospheric processes, and salt tolerance of suaeda by the root mat method. The highest biomass was in the 1.2% salt level for suaeda and in the 0.7% salt level for sugar beet. The root length and root surface area of suaeda showed similar trends to biomass, but the root diameter decreased by 11.5–17.9% with higher salinity. The Na+, Cl−, and K+ accumulations in the shoot of suaeda displayed higher than that in sugar beet, while the Mg2+ accumulation was lower in suaeda than that in sugar beet. High salinity resulted in increased pH and EC values in the rhizosphere for suaeda, but lower values of these parameters for sugar beet. Under high salinity, the Olsen phosphorus content was 0.50 g·kg−1 and 0.99 g·kg−1 higher in the rhizosphere than in the non-rhizosphere for suaeda and sugar beet. We concluded that the two species [halophyte, Suaeda salsa (suaeda), and a glycophyte, B. vulgaris L. (sugar beet)] showed diverse approaches for nutrient absorption under salinity stress. Suaeda altered its root morphology (smaller root diameter and longer roots) under salt stress to increase the root surface area, while sugar beet activated rhizospheric processes to take up more nutrients

    Nitrogen Promotes the Salt-Gathering Capacity of Suaeda salsa and Alleviates Nutrient Competition in the Intercropping of Suaeda salsa/Zea mays L.

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    Nitrogen accelerates salt accumulation in the root zone of an euhalophyte, which might be beneficial for inhibiting the salt damage and interspecific competition for nutrients of non-halophytes in intercropping. However, the variations in the effect of euhalophyte/non-halophyte intercropping with nitrogen supply are poorly understood. Here, we selected the euhalophyte Suaeda salsa (suaeda) and non-halophyte Zea mays L. (maize) as the research objects, setting up three cropping patterns in order to explore the influence of nitrogen application on the intercropping effect in the suaeda/maize intercropping. The results showed that the biomass of maize in the intercropping was significantly lower than that in the monoculture, while for suaeda, it was higher in the intercropping than that in the monoculture. The biomass of maize under NO3−-N treatment performed significantly higher than that under no nitrogen treatment. Moreover, under suitable NO3−-N treatment, more salt ions (Na+, K+) gathered around the roots of suaeda, which weakened the salt damage on maize growth. In the intercropping, the effect of NO3−-N on the maize growth was enhanced when compared with the non-significant effect of NH4+-N, but a positive effect of NH4+-N on suaeda growth was found. Therefore, the disadvantage of maize growth in the intercropping suaeda/maize might be caused by interspecific competition to a certain extent, providing an effective means for the improvement of saline–alkali land by phytoremediation

    Nitrogen–Salt Interaction Adjusts Root Development and Ion Accumulation of the Halophyte <i>Suaeda salsa</i>

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    Nitrogen (N) application might exert a great impact on root (biomass, length) distribution, which possibly contributes to ion and nutrient uptakes. Here, we address the effects of N application on these characteristics to detect how N improves its salt tolerance. Suaeda salsa was subjected to four salt levels (0.5, 1.0, 1.5, and 2.0%) and three N treatments (NO3−-N: 0, 0.25, and 0.50 g·kg−1) in soil column experiments. The N applications performed a “dose effect” that significantly enhanced the growth of Suaeda at low salt levels, while negative effects were displayed at high salt levels. Moderate N markedly benefited from Na+ and Cl− uptake, which was approximately 111 mg and 146 mg per plant at a salt level of 1.0%. Exposure to a certain N application significantly enhanced topsoil root length at salt levels of 0.5% and 1.0%, and it was higher by 0.766 m and 1.256 m under N50 treatment than that under N0 treatment, whereas the higher salt levels accelerate subsoil root growth regardless of N treatment. Therefore, its interactive effects on root development and ion uptake were present, which would provide further theoretical basis for improving saline soil amelioration by N application. Regression analysis always showed that topsoil root length generated more positive and significant influences on ion uptake and vegetative growth than total root length. The results suggested that N application is beneficial to salt tolerance by altering root allocation so as to raise its elongation and gather more ions for halophyte in the topsoil

    Optimal allocation model and method for parallel ‘reservoir and pumping station’ irrigation system under insufficient irrigation conditions

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    Abstract The effective regulation and storage of water resources by reservoirs in arid and semi-arid areas is important for alleviating water resource shortages. In this paper, multiple irrigation reservoirs and pumping stations are evaluated, according to their special hydraulic connections and used to establish the water resources optimal allocation model of the parallel ‘reservoir and pumping station’ irrigation system. The mathematical model takes the maximum total income of the whole irrigation area as the objective function, the water supply and spill of the reservoir and the water replenishment of the pumping station as the decision variables, and the system water supply, agricultural water rights, reservoir operation criteria as the constraints. A new multilevel decomposition aggregation dynamic programming (MDADP) algorithm is proposed to solve the complex nonlinear model and is compared with the real-coded genetic algorithm, particle swarm optimization, cat swarm optimization and whale optimization algorithm. From the analysis of optimality and the applicability of the algorithm, MDADP was found to be more suitable than the above heuristic models for solving problems in the field of the optimal allocation of water resources

    Technology-based cognitive training and rehabilitation interventions for individuals with mild cognitive impairment: a systematic review

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    Abstract Background Individuals with mild cognitive impairment (MCI) are at heightened risk of developing dementia. Rapid advances in computing technology have enabled researchers to conduct cognitive training and rehabilitation interventions with the assistance of technology. This systematic review aims to evaluate the effects of technology-based cognitive training or rehabilitation interventions to improve cognitive function among individuals with MCI. Methods We conducted a systematic review using the following criteria: individuals with MCI, empirical studies, and evaluated a technology-based cognitive training or rehabilitation intervention. Twenty-six articles met the criteria. Results Studies were characterized by considerable variation in study design, intervention content, and technologies applied. The major types of technologies applied included computerized software, tablets, gaming consoles, and virtual reality. Use of technology to adjust the difficulties of tasks based on participants’ performance was an important feature. Technology-based cognitive training and rehabilitation interventions had significant effect on global cognitive function in 8 out of 22 studies; 8 out of 18 studies found positive effects on attention, 9 out of 16 studies on executive function, and 16 out of 19 studies on memory. Some cognitive interventions improved non-cognitive symptoms such as anxiety, depression, and ADLs. Conclusion Technology-based cognitive training and rehabilitation interventions show promise, but the findings were inconsistent due to the variations in study design. Future studies should consider using more consistent methodologies. Appropriate control groups should be designed to understand the additional benefits of cognitive training and rehabilitation delivered with the assistance of technology

    Deficits at Coal Mines Subject to Unified Distribution and the Policy to Reverse Losses

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    Coal is China's primary energy source. Among major countries in the world, coal makes up less than 35 percent of energy consumed whereas in this country, the percentage is over 70. Coal is not only a major fuel for all branches of the economy as well as the home, but also a major industrial raw material.

    The Effects of <i>Suaeda salsa</i>/<i>Zea mays</i> L. Intercropping on Plant Growth and Soil Chemical Characteristics in Saline Soil

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    Halophytes possess the capacity to uptake high levels of salt through physiological processes and their root architecture. Here, we investigated whether halophyte/non-halophyte intercropping in saline soil benefits plant growth and contains root-dialogue between interspecific species. Field and pot experiments were conducted to determine the plant biomasses and salt and nutrient distributions in three suaeda (Suaeda salsa)/maize (Zea mays L.) intercropping systems, set up by non-barrier, nylon-barrier, and plastic-barrier between plant roots. The suaeda/maize intercropping obviously transferred more Na+ to the suaeda root zone and decreased salt and Na+ contents. However, the biomass of the non-barrier-treated maize was significantly lower than that of the nylon and plastic barrier-treated maize. There was lower available N content in the soil of the non-barrier treated groups compared with the plastic barrier-treated groups. In addition, the pH was lower, and the available nutrient content was higher in the nylon barrier, which suggested that rhizospheric processes might occur between the two species. Therefore, we concluded that the suaeda/maize intercropping would be beneficial to the salt removal, but it caused an adverse effect for maize growth due to interspecific competition, and also revealed potential rhizospheric effects through the role of roots. This study provides an effective way for the improvement of saline land

    Engaging With Aging: A Qualitative Study of Age-Related Changes and Adaptations.

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    BACKGROUND AND OBJECTIVES: In the context of global aging, there is a need to better understand how older adults adapt to their changing health status. Engaging with aging (EWA) is an emerging framework proposed by Carnevali, which provides a new lens to understand an active, conscious daily-living process of managing age-related changes (ARCs) taken on by older adults. Study aims were to (a) describe the ARCs experienced by community-dwelling older adults and (b) identify the strategies and resources used by older adults to accommodate the daily-living challenges caused by the associated ARCs. RESEARCH DESIGN AND METHODS: We conducted semistructured interviews using a virtual card sort to gather qualitative data about ARCs and strategies to manage ARCs. Interviews were conducted virtually due to coronavirus disease 2019 (COVID-19) restrictions. RESULTS: Participants included 19 females and 10 males. The mean age was 77.45 years old (range from 64 to 98). Sixteen ARCs (e.g., changes in hearing, changes in stability, changes in sleep, etc.) were mentioned by participants, and their corresponding adaptations were discussed. Participants linked their adaptations to their ARCs based on their changing capacities and needs. Examples of commonly used adaptations included, for example, conserving energy, utilizing tools or technology, and being more conscious before and while taking actions. The challenges caused by COVID-19 in implementing the adaptations were also discussed. DISCUSSION AND IMPLICATIONS: Findings from this study demonstrate how older adults explore, generate, and utilize adaptive behaviors to address their ARCS. This study substantiates the EWA framework by showing common patterns among older adults in linking ARCs with adaptations. Implications for clinicians include using EWA to help older adults identify personalized health solutions that fit their capacities. Researchers may use EWA to design and test interventions by considering the specific ARCs older adults encounter and the attitudes they hold towards the ARCs
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