Selenium fertilizers (Se-fertilizers) were applied to promote the growth of plant and improve the Se content in crops. However, traditional Se-fertilizers have low utilization efficiency of Se due to adsorption or leaching. Herein, Alg-g-Polyacrylamide/Se orange peel polysaccharide (AP/SeOPP) hydrogel was prepared and characterized by FT-IR, SEM, XRD and XPS. The swelling behaviors of AP8/SeOPP3 in different saline solution were investigated. Meanwhile, the rheological properties of AP8/SeOPP3 were studied. The water-retention ratio of AP8/SeOPP3 at -0.08 MPa were 84.9 %. The water-holding capacities of soil with AP8/SeOPP3 (1 wt%) was 33.8 % at 20th day. The pot experiments showed that the Se content of Chinese cabbage treated by AP8/SeOPP3 of 2 wt% was 2.67 mg/kg. Compared with control treatment, the average stem height and fresh weight of Chinese cabbage fertilizered by AP8/SeOPP3 were higher than that treated by AP8 hydrogel. The release mechanism indicated that there was the ion exchange between Cl-, PO43- , SO42- in sandy soil and SeO32- in AP8/ SeOPP3 hydrogel. This work provides a feasible strategy for promoting vegetable growth and achieving Seenrichment of crops in arid and semi-arid region.

The threat of cadmium (Cd) stress to agricultural soil environments, as well as their productivity attracting growing global interest. Tall fescue (Festuca arundinacea Schreb.) is a strong candidate for the remediation of heavy metals in soil. However, the joint analysis of Cd tolerance, physiological responses, and multifaceted plant microbiomes in tall fescue fields has not been extensively researched. Therefore, this study employed microbial sequencing (i.e., 16S and ITS sequencing) to investigate the differences in microbial community structure among various plant compartments of Cd-resistant tall fescue (cv. 'Arid3 ') and Cd-sensitive tall fescue (cv. 'Barrington'). Furthermore, we examined the mechanism of resistance to Cd by introducing three different bacteria and a fungus that were isolated from the 'Arid3 ' rhizosheath soil. It highlighted the potential application of enriched taxa such as Delftia, Novosphingobium, Cupriavidus and Torula in enhancing the activity of antioxidant defense systems, increasing the production of osmotic regulatory substances, and stimulating the expression of Cdresistance genes. This ultimately promoted plant growth and enhanced phytoremediation efficiency. This study shed light on the response mechanism of the tall fescue microbiome to Cd stress and underscored the potential of tall fescue-microbe co-culture in the remediation of heavy metal-contaminated areas.

Plant lead (Pb) tolerance and accumulation are key characteristics affecting phytoremediation efficiency. Bermudagrass is an excellent candidate for the remediation of Pb-polluted soil, and it needs to be mowed regularly. Here, we explored the effect of different mowing frequencies on the remediation of Pb-contaminated soil using bermudagrass. Mowing was found to decrease the biomass and photosynthetic efficiency of bermudagrass under Pb stress, thereby inhibiting its growth. Although mowing exacerbated membrane peroxidation, successive mowing treatments alleviated peroxidation damage by regulating enzymatic and nonenzymatic systems. A comprehensive evaluation of Pb tolerance revealed that all the mowing treatments reduced the Pb tolerance of bermudagrass, and a once-per-month mowing frequency had a less negative effect on Pb tolerance than did more frequent mowing. In terms of Pb enrichment, mowing significantly increased the Pb concentration, total Pb accumulation, translocation factor (TF), and bioenrichment factor (BCF) of bermudagrass. The total Pb accumulation was greatest under the once-a-month treatment, while the TF and BCF values were greatest under the three-times-a-month mowing treatment. Additionally, the decrease in soil pH and DOC were significantly correlated with the soil available Pb content and plant Pb accumulation parameters. The results showed that changes in the rhizosphere are crucial factors regulating Pb uptake in bermudagrass during mowing. Overall, once-a-month mowing minimally affects Pb tolerance and maximizes Pb accumulation, making it the optimal mowing frequency for soil Pb remediation by bermudagrass. This study provides a novel approach for the remediation of Pb-contaminated soil with bermudagrass based on mowing.

Dry cracking and salt enrichment are common deterioration of earthen sites being exposed to soil- air coupled environments. The deterioration of earthen sites cannot be completely prevented by simply maintaining a high relative humidity (RH) of air environment, especially in the absence of supplemental liquid water, because of one-way migration of moisture from earthen sites to air environment. In the current work, a protection strategy of constructing a mist atmosphere over the surface of earthen sites, of which near-saturated air with micron-sized moisture droplets by an ultrasonic water atomization, was proposed to enhance the back diffusion of liquid moisture into earthen sites, and thereby inhibit the deterioration of earthen sites. The experimental moisturizing system with an ultrasonic atomization unit was built in an analogous earthen site exhibition hall in the field of Han Yangling Museum of Xi'an City, China. A series of tests were conducted to evaluate the feasibility and safety of the moisturizing system for earthen sites. The results showed that the moisture content of earthen site topsoil after moisturizing can be recovered to a level close to that prior to excavation of earthen sites, and the fractures once occurring on the surface of earthen site was effectively inhibited; The soluble salt content of earthen site topsoil was significantly reduced, and no salt damage occurred. It is anticipated that this study has a great potential for application to resist the one-way migration of moisture from earthen sites to air environment, and the salt damage and fracture of earthen sites. (c) 2023 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved.

The deposition of light absorbing impurities (LAIs) (e.g., black carbon (BC), organic carbon (OC), mineral dust (MD)) on snow is an important attribution to accelerate snowmelt across the northern Xinjiang, China. At present, there is still a lack of understanding of the LAIs concentration, elution and enrichment process in snow cover over Xinjiang. Based on these, continuously sampling during two years carried out to investigate the concentrations, impacts and potential sources of LAIs in snow at Kuwei Station in the southern Altai Mountains. The average concentrations of BC, OC and MD in the surface snow were 2787 +/- 2334 ng g(-1), 6130 +/- 6127 ng g(-1), and 70.03 +/- 62.59 mu g g(-1), respectively, which dramatically increased along with snowmelt intensified, reflecting a significant enrichment process of LAIs at the snow surface. Besides, high LAIs concentrations also found in the subsurface and melting layers of the snowpit, reflecting the elution and redistribution of LAIs. With the simulation of the SNow ICe Aerosol Radiative model, BC was the main dominant factor in reducing snow albedo and radiative forcing (RF), its impact was more remarkable in the snowmelt period. The average contribution rates of BC, MD and BC + MD to snow albedo reduction increased by 20.0 +/- 1.9%, 13.0 +/- 0.2%, and 20.5 +/- 2.3% in spring compared with that in winter; meanwhile, the corresponding average RFs increased by 15.8 +/- 3.4 W m(-2), 4.7 +/- 0.3 W m(-2) and 16.4 +/- 3.2 W m(-2), respectively. Changes in the number of snowmelt days caused by BC and MD decreased by 3.0 +/- 0.4 d to 8.3 +/- 1.3 d. It indicated that surface enrichment of LAIs during snow melting might accelerate snowmelt further. Weather Research and Forecasting Chemistry model showed that the resident emission was the main potential source of BC and OC in snow. This implied that the mitigation of intensive snowmelt needs to mainly reduce resident emission of LAIs in the future. (C) 2020 Elsevier Ltd. All rights reserved.