Effects of two Mn-based nanomaterials on soybean antioxidant system and mineral element homeostasis

Modern perspectives of heavy metals alleviation from oil contaminated soil: A review

Heavy metal poisoning of soil from oil spills causes serious environmental problems worldwide. Various causes and effects of heavy metal pollution in the soil environment are discussed in this article. In addition, this study explores new approaches to cleaning up soil that has been contaminated with heavy metals as a result of oil spills. Furthermore, it provides a thorough analysis of recent developments in remediation methods, such as novel nano-based approaches, chemical amendments, bioremediation, and phytoremediation. The objective of this review is to provide a comprehensive overview of the removal of heavy metals from oil-contaminated soils. This review emphasizes on the integration of various approaches and the development of hybrid approaches that combine various remediation techniques in a synergistic way to improve sustainability and efficacy. The study places a strong emphasis on each remediation strategy that can be applied in the real-world circumstances while critically evaluating its effectiveness, drawbacks, and environmental repercussions. Additionally, it discusses the processes that reduce heavy metal toxicity and improve soil health, taking into account elements like interactions between plants and microbes, bioavailability, and pollutant uptake pathways. Furthermore, the current study suggests that more research and development is needed in this area, particularly to overcome current barriers, improve our understanding of underlying mechanisms, and investigate cutting-edge ideas that have the potential to completely transform the heavy metal clean up industry.

Investigation of the effects and mechanisms of manganese-based NMs on rice growth

Manganese-based (Mn-based) nanomaterials (NMs) have great potential as alternatives to conventional Mn fertilizers. Yet, its environmental risks and effects on plant growth are not completely well understood. This study investigated the physiological effects of manganese dioxide (MnO2) and manganese tetroxide (Mn3O4) NMs on inter-root exposure (0-500 mg/L) of hydroponically grown rice. The results showed that on inter-root exposure, 50 mg/L Mn-based NMs promoted the uptake of mineral elements and enhanced the enzymatic activities of antioxidant systems (CAT and SOD) in rice, whereas 500 mg/L Mn3O4 NMs disrupted the mineral element homeostasis and led to phytotoxicity. The promotion effect of MnO2 NMs was better, firstly because MnO2 NMs treatment had lower Mn content in the plant than Mn3O4 NMs. In addition, MnO2 NMs are more transported and absorbed in the plant in ionic form, while Mn3O4 NMs exist in granular form. MnO2 NMs and Mn3O4 NMs both can be used as nano-fertilizers to improve the growth of rice by inter-root application, but the doses should be carefully selected.

Insights into the effect of manganese-based nanomaterials on the distribution trait and nutrition of radish (Raphanus sativus L.)

Manganese (Mn) is one of the essential elements for plant growth and is involved in the process of photosynthesis and seed germination. Herein, we applied two Mn-based nanoparticles, MnO2 and Mn3O4, to the soil to investigate their effects on radish growth, antioxidant system, and nutrients. The radish plant height after treatment with 10 mg/kg of MnO2 and Mn3O4 NPs were increased, compare to the control. In radish's shoot, MnO2 NPs at high concentrations (100 mg/kg) increased MDA activity by 58 % compared to the control group, while exposure to Mn3O4 NPs at the same concentration decreased MDA activity by 14 %. The nutrient content of radishes, such as soluble sugar and vitamin C, was improved. Moreover, single particle inductively coupled plasma mass spectrometry (SP ICP-MS) was used to understand the patterns of migration of Mn-based NPs in radish and subsequent impact on nutrients. We found that Mn-based NPs accumulated mainly in the roots of radish. Interestingly, the accumulation characteristics of MnO2 NPs and Mn3O4 NPs were different. MnO2 NPs accumulated more in radish leaves than in fruits, while the accumulation of Mn3O4 NPs gradually decreased from roots to leaves. Finally, we determined the mineral element content of the leaves, fruits, and roots of radish, and found that the uptake of main metallic mineral elements (e.g. Cu, Fe, Mg, Zn, Na, K) was inhibited by the application of Mn-based NPs. These findings underscore the importance of considering species and multifaceted impacts of Mn-based NPs as nanofertilizers for their wide application in agriculture.

The combination of nanotechnology and potassium: applications in agriculture

Potassium fertilizer is indispensable for ensuring crop production, which in turn supports global food supply and safe farming practices. Potassium resources are primarily located in the Northern Hemisphere, leading to a current shortage of affordable potash and severe soil deficiencies in certain regions of the Southern Hemisphere. There is a shift away from mined salts in favor of locally available potassium resources. Utilizing potassium-rich silicates, for instance, could be a viable option to address this situation. The imperative of enhancing crop productivity and quality necessitates either increasing potassium availability or utilizing potassium more efficiently. Geneticists may find the development of plants that use potassium more effectively to be a valuable pursuit. Nanomaterials are increasingly becoming part of people's professional lives as a novel material category. This technology is gradually finding applications in agriculture to boost crop yields while reducing environmental pollution. This paper reviews the applications of common potassium-containing materials, explores the effects and mechanisms of nano-fertilizers on plants, and offers insights into future applications of nano-potassium fertilizers in agriculture. All in all, the application of nanotechnology in the production and utilization of potassium fertilizers is both necessary and effective. However, there are still many gaps in the current field of nano-potassium fertilizer application that require further research. It is hoped that this review can serve as a valuable reference for researchers working in this field.

Influence of Fertilization on Growth and Lead Content of Pepper under Lead Stress

To investigate the effect of fertilization on Pb content in vegetables, pepper was planted in L1645 (the 5 influencing factors are fertilizers (N, P, K), organic fertilizers (sheep manure) and Pb2+; the 4 levels are blank, low, medium and high; a total of 16 treatments) pot orthogonal experiment. The effects of fertilizers on the growth and Pb content in various parts of pepper under Pb stress were analyzed. The results showed that: (1) The Pb content in pepper fruit ranged from 0.011 mg·kg-1 to 0.085 mg·kg-1, which did not exceed the limit value (0.1 mg·kg-1) in the National Standard for Food Safety-Limit of Contaminants in Food (GB2762-2017); (2) The effect order of fertilization on pepper fruit weight was P2O5 > sheep manure > N > K2O; The horizontal combination of factors that promoted the maximum fruit weight of pepper was N (0.15 g·kg-1), P2O5 (0.225 g·kg-1), K2O (0.15 g·kg-1) and sheep manure (9 g·kg-1); (3) The order of fertilizer effects on Pb content in pepper fruit was Pb2+ > K2O > N = sheep manure > P2O5; the factor level combination that resulted in the maximum Pb content in pepper fruits was N (0.15 g·kg-1), P2O5 (0 g·kg-1), K2O (0.45 g·kg-1), sheep manure (6 g·kg-1) and Pb2+ (350 mg·kg-1); (4) Based on the soil fertility characteristics of Urumqi, the recommended optimal fertilizer application rate was: high phosphorus fertilizer P2O5 (495 kg·hm-2), low-level potassium fertilizer K2O (330 kg·hm-2), medium-level nitrogen fertilizer N (660 kg·hm-2) (or low-level nitrogen fertilizer N (330 kg·hm-2) + high-level organic manure sheep manure (19,800 kg·hm-2), which can achieve high yield while ensuring that the Pb content in the fruits does not exceed the standard. Strengthening control of effective and reasonable fertilization methods in Urumqi agricultural land is helpful to reduce the Pb content in vegetables.

Effect of Silica-Based Nanomaterials on Seed Germination and Seedling Growth of Rice (Oryza sativa L.)

The application of nanomaterials (NMs) in agriculture has become a global concern in recent years. However, studies on their effects on plants are still limited. Here, we conducted a seed germination experiment for 5 days and a hydroponics experiment for 14 days to study the effects of silicon dioxide NMs(nSiO₂) and silicon carbide NMs(nSiC) (0,10, 50, 200 mg/L) on rice (Oryza sativa L.). Bulk SiO₂ (bSiO₂) and sodium silicate (Na₂SiO₃) were used as controls. The results showed that nSiO₂ and nSiC increased the shoot length (11-37%, 6-25%) and root length (17-87%, 59-207%) of germinating seeds, respectively, compared with the control. Similarly, inter-root exposure to nSiO₂, bSiO_2, and nSiC improved the activity of aboveground catalase (10-55%, 31-34%, and 13-51%) and increased the content of trace elements magnesium, copper, and zinc, thus promoting the photosynthesis of rice. However, Na₂SiO₃ at a concentration of 200 mg/L reduced the aboveground and root biomass of rice by 27-51% and 4-17%, respectively. This may be because excess silicon not only inhibited the activity of root antioxidant enzymes but also disrupted the balance of mineral elements. This finding provides a new basis for the effect of silica-based NMs promotion on seed germination and rice growth.