Nanotechnology is playing a significant role in addressing a vast range of environmental challenges by providing innovative and effective solutions. Heavy metal (HM) contamination has gained considerable attention in recent years due their rapidly increasing concentrations in agricultural soil. Due to their unique physiochemical properties, nanoparticles (NPs) can be effectively applied for stress alleviation. In this review, we explore the current status of the literature regarding nano-enabled agriculture retrieved from the Web of Science databases and published from January 2010 to November 2020, with most of our sources spanning the past five years. We briefly discuss uptake and transport mechanisms, application methods (soil, hydroponic and foliar), exposure concentrations, and their impact on plant growth and development. The current literature contained sufficient information about NPs behavior in plants in the presence of pollutants, highlighting the alleviation mechanism to overcome the HM stress. Furthermore, we present a broad overview of recent advances regarding HM stress and the possible mechanism of interaction between NPs and HM in the agricultural system. Additionally, this review article will be supportive for the understanding of phytoremediation and micro-remediation of contaminated soils and also highlights the future research needs for the combined application of NPs in the soil for sustainable agriculture.

Nanomaterials in the food industry are used as food additives, and the main function of these food additives is to improve food qualities including texture, flavor, color, consistency, preservation, and nutrient bioavailability. This review aims to provide an overview of the distribution, fate, and environmental and health impacts of food additive nanomaterials in soil and aquatic ecosystems. Some of the major nanomaterials in food additives include titanium dioxide, silver, gold, silicon dioxide, iron oxide, and zinc oxide. Ingestion of food products containing food additive nanomaterials via dietary intake is considered to be one of the major pathways of human exposure to nanomaterials. Food additive nanomaterials reach the terrestrial and aquatic environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. A significant amount of ingested food additive nanomaterials (> 90 %) is excreted, and these nanomaterials are not efficiently removed in the wastewater system, thereby reaching the environment indirectly through the disposal of recycled water and sewage sludge in agricultural land. Food additive nanomaterials also reach the environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. Food additive nanomaterials undergo various transformation and reaction processes, such as adsorption, aggregation-sedimentation, desorption, degradation, dissolution, and bio-mediated reactions in the environment. These processes significantly impact the transport and bioavailability of nanomaterials as well as their behaviour and fate in the environment. These nanomaterials are toxic to soil and aquatic organisms, and reach the food chain through plant uptake and animal transfer. The environmental and health risks of food additive nanomaterials can be overcome by eliminating their emission through recycled water and sewage sludge.

Purpose of Review: This paper offers a thorough overview of the processes of nutrient enrichment by biochar and how biochar as a nutrient carrier can effectively improve agricultural productivity. The distributions of nutrients in biochar and the dynamics of nutrients in soil are also reviewed in detail. Recent Findings: The application of biochar improves soil health by changing the soil’s biological and physico-chemical characteristics of the soil, such as its structure, cation exchange capacity and microbial biomass carbon. Additionally, biochar produced from low pyrolysis temperatures can enhance nutrient retention in soils and be utilized as a carbon-based fertilizer. Summary: The maintenance of an adequate amount of organic matter in soil and a dynamic biogeochemical cycle of essential nutrients are key components of sustainable soil management. Biochar is a carbonized biomass derived from various feedstock materials, including wood and crop residues, manures, biosolids and animal carcasses. Biochar has been used for more than two decades as a soil amendment to improve soil physicochemical conditions and mitigate soil contamination. Nutrient-enriched biochar-based fertilizers (NEBBF) can be prepared using various nutrient enrichment procedures and have the potential to increase soil fertility and crop productivity. The application of NEBBF, which is a carbon-based nutrient source, has been shown to enhance microbial activity, thereby increasing the efficiency of nutrient use compared to conventional non-carbon-based synthetic fertilizers. This review identified key research gaps and discussed the importance and necessity of biochar as a nutrient carrier in agriculture.

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.

China is the major producer of chestnut, with 1.84 million tons of chestnut production, resulting in an enormous waste of chestnut shells. In the current study, shell biochar (SBC) was produced using the inside shell covering fruit, and the outside shell with thorns was used to produce thorn biochar (TBC). Both types of biochar were characterised through Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These analytical results showed a more obvious smooth surface and micro-pore structure in SBC. The vibration of C=O/C=C and C–O (phenolic) showed a significant difference between the two types of biochar. Sorption experiments indicated that the adsorption capacity of the different types of biochar for cadmium (Cd) did not differ significantly, whereas the adsorption capacity of TBC for lead was better than that of SBC. In the pakchoi cultivation experiment (28 days), the application of TBC (1.5%) promoted plant shoot weight, root weight, shoot length and root length by 465%, 143%, 109% and 97% respectively. The application of biochar effectively increased soil pH and reduced the bioavailability and migration of heavy metals. Besides, membrane integrity and chlorophyll content were enhanced because of the alleviation of oxidative stress. Noticeably, application of TBC (0.1% and 1.5%) reduced the Cd concentration in the root by 40–60%, and enhanced accumulation of Pb by 75–191%. Overall, our study demonstrated that 1.5% TBC has promising potential for remediating Cd-contaminated soil. Our study has demonstrated the remediation potential of chestnut and provided a clue for sustainable management of chestnut shell waste for further development of chestnut resources.

Plastics are extensively utilized across various industries due to their affordability, chemical stability, insulation properties, durability, and resistance to water. Nowadays, plastics have become an integral part of modern society, while microplastics (MPs) and nanoplastics (NPs) are rapidly accumulating in soil, which could have detrimental effects on both ecosystems and human health. This review first analyzes the latest literature on MPs, soil and plant, and analyzes the future research trends. The review encompasses the latest findings on the effects of MPs and NPs on higher plants, elucidating the mechanisms of MPs and NPs absorption by plants from the soil and their resulting phytotoxicity. Furthermore, the review underscores the imperative for further investigations aimed at comprehending the long-term repercussions of MPs and NPs on plant growth, physiology, reproduction, and their potential entry into the food chain. Notably, NPs exhibit a unique propensity to translocate via the xylem to various plant organs, including seeds, raising concerns for human health, given their heightened uptake by plant roots compared to MPs. In addition, the impacts of MPs and NPs in conjunction with other environmental contaminants might be amplified. Finally, important concerns and potential future research initiatives in the area are considered. The authors call for urgent action to address the problem of plastic pollution and suggest that a multi-disciplinary approach is needed to find solutions to this global problem.