Biochar-compost as a new option for soil improvement: Application in various problem soils

Due to the synergistic effects of biochar and compost/composting, the combined application of biochar and compost (biochar-compost) has been recognized as a highly promising and efficient method of soil improvement. However, the willingness to apply biochar-compost for soil improvement is still low compared to the use of biochar or compost alone. This paper collects data on the application of biochar-compost in several problem soils that are well-known and extensively investigated by agronomists and scientists, and summarizes the effects of biochar-compost application in common problem soils. These typical problem soils are classified based on three different characteristics: climatic zones, abiotic stresses, and contaminants. The improvement effect of biochar-compost in different soils is assessed and directions for further research and suggestions for application are made. Generally, biochar-compost mitigates the high mineralization rate of soil organic matter, phosphorus deficiency and aluminum toxicity, and significantly improves crop yields in most tropical soils. Biochar-compost can help to achieve long-term sustainable management of temperate agricultural soils by sequestering carbon and improving soil physicochemical properties. Biochar-compost has shown positive performance in the remediation of both dry and saline soils by reducing the threat of soil water scarcity or high salinity and improving the consequent deterioration of soil conditions. By combining different mechanisms of biochar and compost to immobilize or remove contaminants, biochar-compost tends to perform better than biochar or compost alone in soils contaminated with heavy metals (HMs) or organic pollutants (OPs). This review aims to improve the practicality and acceptability of biochar-compost and to promote its application in soil. Additionally, the prospects, challenges and future directions for the application of biochar-compost in problem soil improvement were foreseen.

A comprehensive performance evaluation of the cement-based expanded perlite plastering mortar

A single performance evaluation does not cover all the situations encountered in cement-based plastering mortar applications in walls. This paper proposes a comprehensive performance evaluation method for assessing the cement-based plastering mortar by comprehensively considering the physical characteristics, microstructures, thermal performances, mechanical properties and adsorbability of materials. The relative performances of each test item were compared with standards and previous studies, and the calculation equation of the comprehensive performance value was obtained. In this study, the common cement plastering mortar (CM) and lightweight mortar were mixed with expanded and vitrified beads as aggregates mortar (EVBM), wood fibres, sepiolite and expanded perlite-based plastering mortar (WM) and three types of homemade optimized mortars were moulded as testing specimens. The reference material was marked as CM, and the weights of each parameter in the equation were artificially set according to the applied conditions of the building and restricted by the comprehensive performance value of the ideal plastering mortar at the same time. Through the evaluation of the comprehensive performance and the calculation of these mortars from a case setting of weights, the combined mixing of diatomite, sepiolite with fly ash is better than each single material mixed in mortars, and the comprehensive performance value of mortars with a single function is functional, such as thermal insulation mortar. This paper provides an evaluation method for the comprehensive application of cement-based plastering mortar on the wall.

Combined effects of vermicompost and vermicompost leachate on the early growth of Meloidogyne incognita stressed Withania somnifera (L.) Dunal

Roots of Withania somnifera, an important medicinal herb, are prone to the infection of Meloidogyne incognita (a root parasitic nematode). The infection lowers the quality and quantity of plant material and poses a challenge in crop cultivation and obtaining desirable yield. In the present study, in vitro inhibitory activity of vermicompost leachate (Vcom-L) was assessed against % hatch and survival of M. incognita in a 96 h assay. Then, Vcom-L was used as soil supplement in combination with vermicompost (Vcom) to evaluate their nematode inhibitory and stress alleviating effect in W. somnifera, in a pot experiment. Root galling intensity and growth performance of nematode-stressed W. somnifera raised from seeds pre-soaked in distilled water (DW), Vcom-L, vermicompost tea (Vcom-T) and different dilutions of Vcom-L were assessed. We observed 79% suppression of egg hatching and 89% juvenile (J2) mortality after 96 h compared to control, at 100% concentration of Vcom-L. Significant reduction in gall formation with increase in growth parameters of seedlings was observed after combined application of Vcom (60% or 100%) + Vcom-L and was evident as enhancement in seedling biomass and contents of chlorophyll and protein. However, proline, total phenolics and malondialdehyde (MDA) content declined significantly in these combinations compared to the control (0% Vcom). Activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidise (APX), guaiacol peroxidise (GPX) and glutathione reductase (GR) declined with Vcom as well as Vcom + Vcom-L and corresponded with decline in the accumulation of reactive oxygen species in leaves. Further, 1:5 and 1:10 dilutions of Vcom-L in combination with Vcom (60%) proved beneficial in mitigating the nematode-induced stress in W. somnifera. Present results showed the potential of Vcom and Vcom-L in standardised combination as an effective strategy in controlling the pathogenicity of M. incognita in medicinal plants such as W. somnifera.

Core-shell alum-borneol fiber for high bioavailability

Currently, the treatment of burns poses a significant challenge to clinical surgical. The use of nanofibers combined with drugs provides an entirely new option for treating burns. Alum-borneol combination has been shown as a promising alternative in clinical burn treatment. However, the utilization of the alum-borneol combination is not optimistic due to the low solubility of borneol. In this study, alum-borneol incorporated polyvinyl pyrrolidone fibers with a core-shell structure were fabricated through coaxial electrospinning. In vitro Borneol release behavior of fibers with different ratios of alum to borneol was explored. Scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimeter, in vitro drug release, and in vitro release mechanism were evaluated. The results showed that the fiber membranes maintained an integrated morphology. In vitro dissolution data showed an improved solubility of borneol, which reached more than 82% at 240 min in alum-borneol fibers. It was 4.8 times higher than borneol powder, and the ratio of alum to borneol was 2:1 for the best results. Therefore, alum-borneol incorporated polyvinyl pyrrolidone fibers can significantly improve the dissolution rate of borneol, which opens up a new way for the combined application of the alum and borneol.

The role of biochar in organic waste composting and soil improvement: A review

Large amounts of organic wastes, which pose a severe threat to the environment, can be thermally pyrolyzed to produce biochar. Biochar has many potential uses owing to its unique physicochemical properties and attracts increasing attentions. Therefore, this review focuses on the agronomic functions of biochar used as compost additives and soil amendments. As a compost additive, biochar provides multiple benefits including improving composting performance and humification process, enhancing microbial activities, reducing greenhouse gas and NH₄ emissions, immobilizing heavy metals and organic pollutants. As a soil amendment, biochar shows a good performance in improving soil properties and plant growth, alleviating drought and salinity stresses, interacting with heavy metals and organic pollutants and changing their fate of being uptaken from soils to plants. Furthermore, combined application of biochar and compost shows a good performance and a high agricultural value when applied to soils. Objectively and undeniably, there are still negative or ineffective cases of biochar amendment on crop yield and heavy metal immobilization, which is worthy of further attention. The medium-long term field monitoring of biochar-specific agricultural functions, as well as the exploration of wider sources for biochar feedstocks, are still needed.

Effect of combined application of lead, cadmium, chromium and copper on grain, leaf and stem heavy metal contents at different growth stages in rice

Most studies on plants' response to heavy metal toxicity have been focusing on single metals. However, soils are always contaminated by several kinds of heavy metals. In this study, pot experiments were carried out to investigate the effects of combined toxicity on two rice genotypes differing in Cd accumulation (Xiushui817, a low-grain-Cd-accumulation and Zheda821, a high-grain-Cd-accumulation genotype). Yield, heavy metal concentrations of grain and leaf/stem at different growth stages were measured under combined application of Cd, Cr, Pb and Cu. Yield was significantly decreased under higher Pb and Cd treatment in both genotypes with Xiushui817 showing greater reduction. Increasing soil Cu level showed no significant effect on grain yield. Zheda821 consistently showed a higher grain Cd content than Xiushui817. The application of Pb, Cd, Cr and Cu significantly affected grain Cd, Cr and Cu accumulations. Similar trends were also observed in leaves and stems at harvest stage. The critical levels of leaf/stem Cd and Cr for safe rice production were also estimated. Alleviation measures should be taken to decrease Cd or Cr accumulations in grain of rice if leaf or stem Cd or Cr concentrations at different growth stages exceed the critical levels.

[Biomonitoring application in the exposome assessment]

Biomonitoring can be applied to assess internal exposure and environmental exposure by exposure markers with providing internal exposure to biological characterization and individual exposure information, which is a key tool to evaluate the risk exposure to disease by biological alternation information. With the development of high throughput, broad spectrum and high efficiency screening and detection technology, biomonitoring is defined as traditional biological monitoring (targeted monitoring) and non targeted monitoring analysis (exposomic approaches). An exposomic approach differs from traditional biomonitoring in that it can theoretically include all exposures of potential health significance, whether they are derived from exogenous sources. Both traditional and nontraditional biomonitoring methods should be used to understand the complexity of exposures faced throughout the lifespan. Through hybrid approaches, emerging techniques and the integration of bioinformatics, and developing the detection methods for low abundance chemicals, improving the differentiation ability between endogenous and exogenous chemical, the health outcomes and exposures can be widely recognized and characterized, which can finally contribute to improving the precise prevention and intervention for diseases under the new exposomic model.

Clinical drugs for reflux esophagitis

Reflux esophagitis (RE) is a common clinical disease with complex etiology and high incidence which is increasing year by year. Although conventional treatments can ease patients' symptoms, the long-term prognosis is unsatisfactory with many adverse reactions and recurrent symptoms. This article discusses the physiological functions, therapeutic effects and combined application of clinical drugs for reflux esophagitis, with an aim to provide guidance for the treatment of this disease.