Most major crops in agricultural soils exhibit relatively low nutrient use efficiency for nitrogen (N), phosphorus (P), and potassium (K), often necessitating supplemental nutrient inputs to achieve sustainable yields. Furthermore, the increasing use of biowastes such as compost, manure, and biosolids, which frequently have nutrient ratios that do not match crop requirements, has contributed to excessive nutrient inputs and subsequent accumulation in soils. This situation has been further exacerbated by intensive farming practices involving multiple cropping cycles per season. Overuse of nutrients causes them to accumulate in the soil, creating a legacy nutrient pool. The application of biochar as soil amendment is considered a potential strategy to control legacy nutrients dynamics. The current review inspects the possible value of biochar in modulating legacy nutrient reserves in the soil, thereby increasing the bioavailability of nutrients and improving crop yield. This review discusses the search scope and synthesis approaches for the bibliometric methodological component through rigorous screening process (Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)), focusing on journal articles published in last 20 years that specifically address legacy nutrient management. The significance of the economic and environmental effects of legacy nutrients and the insufficient knowledge of how biochar application influences nutrient dynamics in soil highlight the necessity for additional research to address current gaps.

Climate change is accelerated by increasing levels of greenhouse gases (GHGs) as a result of human activity, particularly the release of carbon dioxide (CO2). Soil carbon (C) sequestration, or the transfer of atmospheric CO2 to soil organic matter (SOM) with long-term stabilization within the soil, is an important process of C removal from the atmosphere. For the accounting of soil C and offset markets in most countries including Australia, the standard soil sampling depth is 0–30 cm, although deeper sampling is recommended for more accurate C stock assessments and to capture long-term sequestration potential. While 30 cm soil depth accounts for most short-term management impacts on C storage, a significant portion of soil C is stored below this depth (i.e., deep soil C), and sampling at greater depths can provide a more complete account of total C stocks and potential sequestration benefits. This paper aims to provide a comprehensive review, including a bibliometric analysis and a critical discussion of the link between deep soil C storage and sequestration potential in relation to climate change mitigation and soil health. Deep soil layers contain over 850 Pg C worldwide, which is approximately 50

The extensive occurrence of microplastics (MPs) in both aquatic and terrestrial environments requires enhanced detection, characterization, monitoring, and management approaches. Researchers have made significant progress in making MPs detection more efficient, accurate, and scalable by combining artificial intelligence (AI) with analytical techniques like Raman spectroscopy (RS), Fourier transform infrared spectroscopy (FTIR), image processing (IP), and hyperspectral imaging (HSI). India, China, and the USA have been recognized as major contributing countries in terms of global MPs pollution. Netravathi River in India has the maximum MP pollution of 288 pieces/m3, 96 pieces/kg, and 84.45 pieces/kg, respectively in water, sediment and soil. In China, the Inland freshwater lakes of Wuhan have the maximum MPs pollution of 1660.0 ± 639.1-8925 ± 1591 n/m3 in water. In the USA, San Francisco Bay, California, has the maximum MPs pollution of 15,000-2,000,000 particles/km2. Furthermore, the application of Machine Learning (ML) algorithms incorporated FTIR, Raman, and HSI have provided better efficacy (99 %, 99.1 %, and 97 % respectively) in detection and characterization of MPs. This study emphasizes the need to understand the foundational concepts, data resources, preprocessing methods, and limitations of the ML algorithms employed in the identification, detection, distribution, and management of MPs. Also, novel prospects for research and development on combining ML technologies were explored. Overall, AI and environmental science can revolutionize MPs research by providing powerful tools for real-time monitoring and mitigation, preserving ecosystem health.

Green chemistry is defined as a set of principles that reduce or prevent the use or generation of hazardous substances during the design, production, and utilization of chemical products. The vision of such a paradigm shift in the chemical sciences is that the concept of being green is directly introduced to the molecular design process and is centered on atom economy and the prevention of waste. This review examines the principles of green chemistry in relation to agro-industrial waste valorization, with specific reference to the ecological and economic conditions of India, where approximately 350 million metric tons of annual agro-residues have become a source of serious environmental management issues, such as greenhouse gas emissions through open burning, leachate waste generation through landfills, and effects on the health of the population through poor disposal practices. The analysis summarizes the latest developments in nanotechnology-based catalytic systems, new solvent platforms (ionic liquids, deep eutectic solvents, and supercritical fluids), and integrated biorefineries, and critically reviews the scalability limitations and commercial feasibility. It also discusses more recent developments, such as systems based on nanotechnology, catalyst transformations (homogeneous, heterogeneous, and biocatalysts), and the creation of alternative solvents, such as ionic liquids, deep eutectic solvents, and supercritical fluids. The virtues of agri-industrial residues and biomass-based feeds are given particular attention in terms of their role in models of the circular economy and the generation of value-added chemicals, fuels, and materials. By illustrating how green chemistry can minimize the environmental footprint of traditional processes and create safer and more economically viable alternatives, this review makes it clear why green chemistry has become a revolution in the field of industrial practice. Lastly, the paper addresses contemporary issues of scalability, economic competitiveness, and regulatory integration and outlines opportunities that will make green chemistry the foundation of sustainable, resource-efficient, and environmentally responsible chemical companies.

Biochar is a climate-positive green material that has proven its potential application in various sectors related to the circular economy, including waste management, wastewater treatment, global climate change mitigation, sustainable agriculture, and the construction industry. Although many hundreds of studies have explored the applications of biochar, the existing literature remains highly segregated, largely focused on isolated or specific sectoral applications due to the diverse properties. To date, no comprehensive review has conceptualized biochar as a protagonist in the circular economy of cities. An approach is urgently needed to assess how biochar can contribute holistically to sustainable city development—bridging production, utilization, and long-term urban planning for resilience. This includes examining both economic and environmental returns, establishing sustainable supply chains for scaling up biochar solutions. Since biochar has diverse properties and context-dependent applications, it is also suitable to propose a model biochar-integrated city at a pilot scale to investigate real-world problems, limitations, and transformative potential. This demonstration can serve as a blueprint for future urban sustainability planning worldwide. Thus, by highlighting biochar as a crucial component of urban resilience, this article seeks to promote the idea of a sustainable city supported by the ideas of the circular economy.

In this study, the life cycle assessment technique is used to assess and compare the environmental effects of existing plastic waste management scenarios based on the impact categories in India. The study considered end-of-life (gate-to-grave) treatment scenarios for plastic wastes, including landfilling, incineration, recycling, and pyrolysis. All four scenarios were assessed and compared based on their environmental impact using the CML 2001 baseline method in GaBi software. The results proved that landfilling had the least environmental impact in abiotic depletion potential, acidification, global warming, and human toxicity potential, followed by recycling. Pyrolysis and incineration had the most negative impacts on the environment. Transport distance (40 and 100 km) has minor environmental impact (mostly <2% change). However, pyrolysis is most sensitive to distance (similar to 5% increase). This study might help policymakers and municipal bodies implement better plastic waste management plans.

Rapid population growth, urbanization, industrialization, and poor wastewater treatments are increasing heavy metal pollution and worsening global water scarcity. These problems posing serious threat to environmental sustainability, food safety, and human health. Globally, about 359 billion cubic meters of wastewater are generated annually, yet nearly 80% is discharged into ecosystems without proper treatment, lead to the accumulation of toxic metals in ecosystems and the food chain. Prolonged exposure to these metals can cause severe neurological, cardiovascular, and carcinogenic disorders. Although conventional wastewater treatment technologies are effective, but their large-scale application remains constrained by operational costs, energy demand, chemical consumption, complex processes, secondary pollution, and hazardous sludge generation. These limitations highlight the urgent need for sustainable, low-cost, and eco-friendly remediation approaches, particularly in resource-limited regions of world. This review critically examines the agro-waste derived bioadsorbents as green, sustainable, regenerable and cost-effective alternative for wastewater treatment within the framework of waste valorization and circular economy. Unlike previous studies that mainly focused on removal efficiency only, this review provide a comprehensive evaluation of agro-waste based biosorbent, including their preparation, characterization techniques, adsorption mechanisms, isotherm and kinetic models, influencing factors, and comparative assessment with conventional and emerging wastewater treatment technologies. A critical synthesis of studies published between 2001 and 2025 reported that raw biosorbents achieved 60–90% contaminant removal efficiency, whereas chemically modified and thermally activated biosorbent showed significantly higher removal efficiency of 90–97% and up to 99%, respectively. These findings confirm the strong practical potential of agro-waste-derived bioadsorbents for large-scale wastewater treatment. The novelty of this review lies in its holistic perspective of their scientific performance along with sustainability, feasibility, and environmental benefits in line with waste-to-wealth paradigm and sustainable development goals (SDGs). Overall, agro-waste based bioadsorbent offer a promising and greener solution for wastewater treatment that can reduce environmental footprint and support global water security. Therefore, future research should be focused on hybrid treatment system, improved biosorbent modification, standardized testing protocols, techno-economic assessment and pilot-scale validation to support real-world implementation.

Speedy decomposition of organic manure and efficient utilization of rice husk waste are two critical challenges for sustainable environment and soil health management. However, understanding the synergistic effects of rice husk biochar (B) and organic manure (OM) on soil properties and crop growth in subtropical conditions remains unclear. A field study was conducted to investigate the impact of sole and combined application of rice husk biochar (0 t ha-1, 3 t ha-1), farmyard manure (FYM), and vermicompost (VC) on soil aggregation, aggregateassociated carbon, water use efficiency (WUE), economic benefits, and yield of radish crop in sandy clay loam organic soil. Biochar application enhanced the macroaggregate stability and aggregate associated C contents. Soil moisture, infiltration rate (IR) and WUE were significantly improved by 9.2%, 20.8% and 13.6%, respectively, with addition of biochar, which might be related to improved aggregate-associated carbon and water retention in the soil. Similarly, improved soil properties, WUE were noticed in the treatment receiving combination of FYM + VC over the control. 16% and 30.9% higher radish yield was observed with biochar and FYM + VC amended treatments compared without B0 and manure OM0, respectively. The integrated use of biochar (3 t ha-1) and OM (FYM + VC) resulted in highest economic benefits of net return (Indian Rupee 138,325 ha-1) and B:C (1:5) ratio and least in control plots. These results indicate that adding biochar in organic management practices considerably improved the soil properties, WUE which resulted in increased organic radish production.

Abstract Emerging contaminants (ECs) pose a growing threat to the agricultural ecosystems and human health. Biochar (BC) may be applied for the remediation of ECs in soils and water. There are some research papers that have been published about the potentiality of BC for the remediation of ECs in soils and water; however, there have been no critical and comprehensive review articles published on this topic up to now. Therefore, this review explores the application of pristine and modified BC for the remediation of various emerging inorganic contaminants (EICs), including vanadium (V), antimony (Sb), thallium (Tl), mercury (Hg), fluoride (F−), and rare earth elements (REEs) in soils and water. The review explores the specific mechanisms by which BC removes these EICs from water and soil. The roles of ion exchange, complexation, electrostatic interactions, and precipitation in the removal of these EICs from water by pristine and functionalized BC have been reviewed and discussed. Particular attention is also paid to the interaction and potential immobilization of those EICs in soils with pristine and functionalized BC, highlighting some applicable strategies for treating EIC-contaminated soils, particularly paddy soils, aiming to mitigate the associated ecological and human health risks. Finally, the potential environmental implications and further research on the applications of pristine and functionalized BC for remediation of EICs in water and soils have been summarized. This article provides a comprehensive overview on the potential applications of different pristine and engineered BCs for the sustainable remediation of EICs contaminated soils and water. Graphical Abstract

Soil microbial communities—including bacteria, archaea, fungi, and viruses—play a pivotal role in mediating critical nutrient cycling processes (carbon, nitrogen, and phosphorus transformations) that underpin agricultural productivity and ecosystem resilience. Recent advancements in high-throughput sequencing, multi-omics (metagenomics, metatranscriptomics, metabolomics), exudate chemistry, isotope-tracing, and synthetic microbiome engineering (SynComs, microbial inoculants) have enabled mechanistic insights into how soil microbiomes regulate nutrient fluxes under diverse agroecosystem contexts. This review synthesizes findings from 2019–2025 regarding: (1) microbial community composition and functional potential; (2) microbial mechanisms underlying N, P, and C cycling; (3) the impact of agricultural practices (fertilizer regimes, tillage, crop rotations, cover cropping, organic amendments) on soil microbiomes and nutrient dynamics; (4) emerging technologies and strategies for microbiome-based nutrient management—including SynCom design, host genotypic selection, and precision agriculture tools; and (5) major challenges such as context dependency, reproducibility, scale-up logistics, and socio-economic barriers. We propose research priorities including trait- and interaction-focused approaches, coordinated multi-site field trials, host-microbiome co-selection, digital decision-support integration, and supportive policy mechanisms to realize robust, field-deployable microbiome-based strategies for sustainable agriculture.