Introduction

The rapid growth of the world’s population, combined with climate change and changes in land use, has placed significant pressure on soil, water, and agricultural systems (Food and Agriculture Organization of the United Nations, 2017; Youssef et al., 2024; Weiberg et al., 2021). Soil compaction has emerged as a major concern affecting agricultural production and sustainability. This issue, largely attributed to increased mechanization in agricultural practices, has been shown to lead to significant loss of arable land. A recent study found that severe soil compaction can result in crop yield losses of 50% or more, depending on the level of compaction (Shaheb et al., 2021).

To address the challenges in the agricultural sector and ensure food security, it is crucial to employ innovative measures to enhance soil health and reduce the negative impacts of soil compaction. The use of soil amendments has been identified as an effective method for improving soil porosity and reducing compaction (Gupta et al., 2023; Rashmi et al., 2024). Additionally, soil amendments play a significant role in enhancing irrigation water use efficiency (Ferretti et al., 2024) and increasing overall soil productivity (Mali et al., 2020; Shukla et al., 2024). The mechanisms of amendments work by increasing the pore space and reducing the bulk density of the soil. However, this issue is worsened by the frequent use of agricultural machinery during tillage, irrigation, and harvesting (Pitla et al., 2016; Figure 1), ultimately leading to reduced crop yields (Yu et al., 2024). Additionally, in many developing countries, soil compaction is intensified by the weight of grazing animals rather than mechanization (Bertonha et al., 2015). Soil compaction hinders root penetration and nutrient uptake, resulting in poor crop growth and loss of yield (de Moraes et al., 2020; Yu et al., 2024).

Figure 1.

Soil compaction due to agricultural machinery impact (Some icons created in BioRender. Alkhaza’leh, H. (2024)  https://BioRender.com/b61r626).

Soil compaction has effects beyond reducing agricultural production. It reduces infiltration rates, increasing the risk of runoff and soil erosion (Alam et al., 2017). Traditional soil amendments such as organic farm wastes, lime, and gypsum have contributed to improving soil health and agricultural production. However, recent developments in nanotechnology (NT) offer a promising path to overcome the challenges facing the agricultural sector and soil by increasing soil fertility and pest control. It also has the potential to improve soil mechanical properties, increase soil strength, and reduce compaction (Alsharef et al., 2020; El-Sharkawy et al., 2022; Rajabi et al., 2021).

Nanoparticles, which are particles with diameters less than 100 nm, are essential to NT components. Their unique size-dependent physicochemical properties differentiate them from bulk or micron-sized particles (Dasgupta et al., 2017; Verleysen et al., 2019). NPs can be formed through natural processes such as dust storms, volcanic ash, and artificial synthesis methods (Buzea et al., 2007; Chimbekujwo et al., 2024). The metal-based nanoparticles (NPs) have a long persistence (Ameen et al., 2021; Li et al., 2012). Therefore, the introduction of NPs into ecosystems raises significant environmental concerns for both human health and ecological integrity (Adhikari, 2021). Historically, the unique characteristics of NPs have made them useful in various industries such as agriculture, food production, environmental management, pollution control, and energy. These qualities make NPs valuable for addressing climate change and sustainability goals (Chausali et al., 2023; Choudhary et al., 2023; Mohammed et al., 2023).

Recent research has primarily focused on demonstrating the effects of NPs on the physical and hydrological properties of soil for construction purposes. At the agricultural level, studies have addressed their effects on plant nutrition (Iqbal et al., 2024; Komendova et al., 2019; Sharifnasab et al., 2016; Sharma et al., 2024; Younis et al., 2021;). Several studies have explored the role of NPs in influencing soil water dynamics, revealing that the materials used and the properties of the parent soil had a reciprocal effect on the mechanism and behavior of the medium (Elahe et al., 2024; Gill et al., 2024; Komendova et al., 2019). Additionally, physical and chemical variables such as soil texture, moisture content, pH levels, and nutrients affect the interaction and behavior of NPs in soil (X. Gao et al., 2019; Figure 2).

Figure 2.

Nanotechnology approaches in soil reclamation (Some icons created in BioRender. Alkhaza’leh, H. (2024)  https://BioRender.com/b61r626).

The use of NPs to enhance agricultural soil strength is an exciting possibility for future research (Sonderegger & Pfister, 2021; Stolte et al., 2016). However, current research indicates that NP exposure has various effects on plants, such as differences in crop production and potential cytotoxicity, with many studies still in their early stages. Therefore, a review of recent studies on the role of NPs in improving physical properties is necessary, especially given the ongoing advancements in NT, to enhance our understanding of their potential in reclaiming agricultural soil. In this paper, a comprehensive analysis of certain NPs is presented, with a focus on their role in enhancing the physical and microstructural properties of soil. The paper also examines the interaction mechanisms that influence soil behavior and compaction. Additionally, it briefly discusses the potential toxic effects of NPs on human health and ecosystems. The final section assesses the economic viability and sustainability of NP applications, as well as the regulatory frameworks governing their use and waste management.

Nanoparticles Used in Soil Reclamation and Protection

Nanoparticles show promise in improving compacted soil in agriculture. However, it is important to thoroughly document the effects of NPs on the physical characteristics of soil, especially in geotechnical and geological engineering and construction. Nanotechnology (NT), which involves manipulating and utilizing materials at the nanoscale (generally below 100 nm), has been developed and used for environmentally sustainable and cost-efficient soil improvement in geotechnical, geological, and engineering applications. NPs promote flocculation, increasing soil porosity, and reducing bulk density, thereby mitigating the effects of soil compaction (Harsh et al., 2023; Krishnan & Shukla, 2019; Taha & Taha, 2012; Zhang, 2007). In agriculture, nanotechnology (NT) has been used for plant nutrition, protection, and increased productivity (see Table 1). In 2006, the US National Research Council (NRC, 2006) highlighted the introduction of NT in geotechnical materials, creating clay-sized particles of 0.002 mm. Over time, NT applications for soil enhancement have evolved to align with the principles of sustainable development (Liu et al., 2020). This paper explores various environmentally friendly NPs and their potential for soil treatment, especially in reducing soil compaction and for agricultural use. These NPs include Carbon nanotube (CNT), nanozeolites (NZ), nanosilica (NS), Nano-Clays (NCs), Nano-Calcium Carbonate “CaCO₃” (NCC), and Nano-Aluminum Oxide “Al₂O3” (NAO).

Table 1.

Summary of Nanoparticles Used in Soil Reclamation.

Carbon nanotubes

Carbon nanotubes (CNTs) are formed from extremely thin, concentric graphene sheets. CNT atoms are arranged in a hexagonal “honeycomb” pattern to create multi-walled carbon nanotubes (MWCNT) and single-walled carbon nanotubes (SWCNTs; see Figure 3). CNTs vary in length and size, ranging from a few hundred nanometers to several micrometers (Brock, 2004; Herrero-Latorre et al., 2015). CNTs have diverse applications in industries, agriculture, and the environment, including use in sports materials, battery electrodes, LCDs, transparent films, and supercapacitors (De Volder et al., 2013; Wieland et al., 2021). CNTs have a large specific surface area and can effectively absorb chemicals and biological toxins, especially in aquatic environments, making them a promising and environmentally friendly option in the field of environmental science (Alobaid et al., 2022; Hsu et al., 2023; Li et al., 2013). Over the past two decades, CNTs have consistently demonstrated reliability in agricultural applications, particularly in the controlled release of fertilizers and herbicides, which contributes to their stability and effectiveness (Abd-Elsalam, 2019; Bisinoti et al., 2019; Giraldo et al., 2014; Tiwari et al., 2014).

Figure 3.

The chemical structure of (a) single-walled and (b) multi-walled carbon nanotube (Created in BioRender. Alkhaza’leh, H. (2024)  https://BioRender.com/c02s558).

The exceptional flexibility and unique physical properties of CNTs are due to their high-dimensional structure and extremely high flexibility (Fakhim et al., 2012; Sathurusinghe et al., 2012; Terrones, 2004; Xu & Jiang, 2023). The use of CNTs in soils results in significantly stronger and stiffer matrices, which enhances their physical and geotechnical potential as reinforcing fillers to improve soil strength and stability (Liu et al., 2020; Taha, Alsharef, Al-Mansob, & Khan, 2018; Taha, Alsharef, Khan, et al., 2018). While the mechanisms governing the interaction of CNTs with soil are not fully understood, CNTs have the potential to enhance soil behavior and reduce compaction. This underscores the need for further research on their impacts (Morais et al., 2024).

Most of the reviewed studies focused on improving the physical structure and soil stability for non-agricultural purposes. Morais et al. (2024) enhanced the compressive strength of clay soil by using CNTs. The liquidity and flexibility tests showed a decrease of 10% and 13% respectively. Zhao and Xu investigated the effect of adding 2% CNT to sand, and the results showed a 36% increase in the sand’s modulus of elasticity with a hydrostatic pressure increase from 100 to 300 kPa. According to Alobaid et al. (2022), CNTs show great potential for soil reclamation. The treatments resulted in a decrease in soil specific gravity from 2.6 to 2.53 and an increase in soil dry density from 1.48 to 1.49 g/cm³ using 0.05% of CNTs. Additionally, CNTs improved the hydraulic retention time by causing a slight decrease in hydraulic conductivity, which helped reduce soil cracking. Arabania et al. (2012) also studied the blending of clayey sand with CNTs (0.05%–3% by weight of the soil). The soil’s compressive strength increased by about 120% when it contained 3% CNTs compared to the reference clay soil. These studies suggest that even a small amount of CNTs can significantly improve soil compressive strength. Additionally, CNTs reduce the friction angle while increasing the cohesiveness between soil grains. These findings suggest that CNTs may have the potential for agricultural soil reclamation. Further experiments going to help clarify the capabilities of CNTs in this field.

Nanozeolites

Nanozeolites (NZ) are porous crystals composed mostly of Si, Al, and O atoms. Their most important current application is in sustainable, green chemical processes. Synthetic NZ is preferred over natural zeolites due to its superior purity (Asgar Pour et al., 2023; Figure 4). Zeolites come in various forms and are used in many industrial applications. They are commonly found in volcanic and sedimentary materials (Holmberg et al., 2003; Niwa et al., 2010). When in their nano form, zeolites are used as catalysts in the chemical industry, providing high surface areas and shape/size selectivity (Yilmaz, 2009). NZ have been successfully produced and utilized in various petroleum chemical processes, such as catalytic cracking, hydrocracking, and hydroisomerization. NZ are efficient catalysts in methanol conversion processes, where crystal size impacts activity, product distribution, and coke production (Palčić, 2021). Furthermore, New Zealand-generated thermoelectric waste is beneficial for treating wastewater, particularly in nano-adsorption and Fenton-like processes (Oviedo, 2021).

Figure 4.

Micrography of zeolite, silica, and clay. Images from “Selvam et al., 2020, and Arulmurugan and Venkateshwaran, 2021” (used according to the Creative Commons Attribution 3.0 Unported License and STM permission guidelines, respectively), and “Richard et al., 2022” (used with permission from the Copyright Clearance Center’s RightsLink® service; Order Number: 5881860570738, Order Date: Oct 4, 2024).

Nanozeolites have shown significant potential in agriculture, especially in the development of nanofertilizers. These nanofertilizers can slowly release nitrates into the soil (Tsintskaladze, 2017), thereby reducing groundwater contamination and soil toxicity, minimizing fertilization losses, and increasing the soil’s capacity for holding nutrients and water. This can help mitigate the negative effects of overdosing (Feng et al., 2022; Manjunatha, 2019). In addition to improving nutrient delivery in precision farming and restoring soil health and fertility (Pimsen et al., 2021; Hamad, 2020), NZ substantially enhance the geotechnical properties of clayey soil and increase the compression strength of fine-grained soil (Goodarzian, 2020).

The interaction mechanism between soil and NZ particles is a balance of attractive and repulsive forces, with electrostatic forces playing a crucial role in forming or separating aggregates by promoting soil particle binding (Hu et al., 2019). NZ, when combined with other NPs, may effectively solve soil cracking and compaction (Taha & Taha, 2012). Öncü and Bilsel (2017) assessed the effectiveness of combining zeolite with clay soil in a semi-arid climate. The results showed that using a soil/zeolite ratio of 0.5 reduced observed swelling potential by 85%, and shrinkage and compression by 30% to 34%.

A study by Balkaya (2015) observed that zeolite exhibits physical stability and has potential applications in geotechnical and environmental engineering. The samples showed low compressibility, with cohesion (c) values ranging from 0 to 25 kPa and an internal friction angle (ϕ, shear strength coefficient) ranging from 44° to 37°. Yukselen-Aksoy (2010) found that loamy clay soil supported with zeolite has moderately high internal friction angles (34° to 36.5°), making zeolites mechanically stable. The zeolite samples’ free swelling index (FSI) was estimated to be about 2.0, indicating low swelling potential. While most studies focus on geotechnical applications, zeolites, especially NZ, combined with other nanomaterials, can effectively address agricultural soil cracking and compaction.

Environmental and Health Implications of Nanoparticle

Nanoparticles (NPs) have a complex dual impact, yielding both positive and negative effects on the environment and human health. Their unique physicochemical properties make them useful for applications in water treatment and pollution remediation (Kumar et al., 2019; Yamini et al., 2023). Despite their nano size and increased reactivity, these attributes pose significant eco-toxicity concerns that could result in major environmental challenges (Abbas et al., 2020; Ramanathan et al., 2019). Alongside environmental issues, health hazards linked to NPs are a major concern. Research by De Matteis (2017) and Świdwińska-Gajewska (2007) found that the nano size of NPs allows them to evade systemic barriers, particularly when inhaled, which is a significant route of exposure. NPs toxicity often manifests as inflammation, which can be triggered by oxidative stress (Świdwińska-Gajewska, 2007; Tee et al., 2016). Thus, robust methods for assessing occupational exposure and conducting toxicological studies are essential for understanding and mitigating health risks (Adamcakova-Dodd et al., 2014; O’Shaughnessy, 2013). Several factors influence the toxicity of NPs, including their surface properties, the generation of free radicals, and their specific characteristics (Fu et al., 2014; Warheit et al., 2008). Multiple factors influence the environmental impact of NPs, including their physicochemical properties, manufacturing processes, and ecological stability (Joudeh & Linke, 2022; Martínez et al., 2020). A key factor in assessing the environmental impact of NPs is their movement within soil and water systems, which can contaminate groundwater and disrupt ecosystems (Pérez-Hernández et al., 2020; Zheng et al., 2022). Migration is influenced by several factors, including particle size, surface charge, and organic content, all of which can hinder the mobility of NPs (Wang et al., 2016). Additionally, NPs experience changes that affect their movement, particularly during freeze-thaw cycles. The soil type and its moisture content also play significant roles in determining their mobility (Xu et al., 2021). The physical and chemical properties of NPs and their surrounding medium influence their retention and movement. The size of agglomerates is often more significant than the size of the primary particles (Darlington et al., 2009). A thorough understanding of these interactions is essential for addressing potential environmental concerns related to NPs and their long-term behavior in soil and groundwater systems (Sun et al., 2022).

Several studies have indicated that NPs are generally non-toxic to soil and groundwater systems (Alazaiza et al., 2021; Kang et al., 2008; Li et al., 2013; Rajan, 2011). However, some research suggests that NPs may pose minor to moderate environmental concerns (Lead et al., 2018; Pérez-Hernández et al., 2021). Krug (2014) explored the methodologies used in various nanotoxicology studies, critiqued certain research approaches, and suggested that improved study designs could yield more accurate and reliable outcomes. Most risk characterization ratios (RCRs) for NPs are below one. However, some NPs, such as CNTs, have RCRs that exceed one (Arvidsson, 2018; Spinazzè et al., 2021). While the environmental risks associated with the NPs reviewed are generally low, there are significant gaps in knowledge, particularly concerning ambient concentrations and dosimetry methods (Lead et al., 2018).

Several organisms are utilized to evaluate potential health risks. Such as the fruit fly (Drosophila melanogaster) serves as a valuable and cost-effective model organism due to its genetic similarities to humans. This makes it a reliable tool for accurately assessing toxicity (Chifiriuc et al., 2016; Vecchio et al., 2013). Traditional methods for eco-toxicity testing can also be applied to NPs, and research involving algae has demonstrated their high sensitivity to these substances (Boros and Ostafe, 2020). Additionally, leaching testing protocols are becoming an essential tool for examining the behavior of NPs in different environments and evaluating their environmental impact (Brunelli et al., 2021; Moghal et al., 2023). Leaching testing protocols offer an effective short-term alternative to traditional methods like using nano-calcium silicates in soil. They reduce metal extraction rates and enhance soil stability by encapsulating heavy metals, which helps prevent their migration into groundwater (Moghal et al., 2023).

Additionally, Computational methods, such as quantitative structure-activity relationship (QSAR) models, have enhanced our understanding of the toxicity of NPs and their associated health risks (Kleandrova et al., 2014). However, uncertainty still exists, particularly due to technological advancements that could alter the concerns regarding the increased release of particles into the environment (Lead et al., 2018). Therefore, further research is necessary to address these knowledge gaps and ensure the safe and sustainable use of NPs in various agricultural and industrial applications.

Economics, Sustainability, and Regulatory of Nanoparticles

Nanotechnology has the potential to improve soil and plant nutrition in agriculture, offering more affordable and environmentally friendly alternatives to current methods (Singh et al., 2021). The economic feasibility of using NPs in agriculture depends on production and application costs. However, the long-term benefits, such as increased agricultural yields and improved soil health, far outweigh the initial costs (Yadav et al., 2023). Nevertheless, significant obstacles are present, including high manufacturing costs, limited availability, concerns about toxicity, and high energy requirements for synthesis, resulting in increased carbon emissions (Pallas et al., 2018).

The challenges mentioned above are important, particularly in developing countries. High initial costs, unclear regulations, and uncertainty in environmental risks make it difficult to adopt NT, despite its potential to address food insecurity (Acharya & Pal, 2020). Furthermore, potential benefits for rural populations in developing regions are greater than in developed countries (Rathore & Mahesh, 2021). On the other hand, the “green and clean” claims often associated with NPs are not universally applicable, especially in the energy sector, where life cycle assessments indicate high energy consumption and carbon emissions from production processes (Pallas et al., 2018).

Despite this, the emerging field of nanoeconomics combines nanoscience and economic theory, which can speed up technological advancements and encourage more sustainable economic growth. Some potential benefits include cost reductions, lower toxicity, improved efficiency, and increased reliability across various applications. However, it is important to thoroughly assess the full environmental costs of complex engineered nanomaterials to ensure they contribute to sustainable development sound (Dave & Chaturvedi, 2021).

It is crucial to establish regulatory guidelines for the use of NPs in agriculture. Current regulations may not fully address the unique properties and risks associated with NPs, highlighting the need for tailored policies. Conducting thorough risk assessments, implementing proper handling, storage, and disposal practices, and ensuring compliance with safety standards are essential steps to facilitate the safe development of NT (Nath et al., 2021). Additionally, collaboration among stakeholders, including researchers, policymakers, and industry leaders, is necessary to develop comprehensive regulations that consider both environmental and health impacts.

Concerns about nanowaste management and the need for adequate regulatory policies persist (Suman & Pei, 2022). Current waste management systems are often ill-equipped to handle nano-waste, necessitating new approaches and regulations (Musee, 2011). Effective nanowaste management requires proper detection, segregation, and treatment techniques, which depend on the specific class of engineered NPs involved (Gupta & Bharti, 2022). Further research is needed to understand the life cycle of NPs and their long-term effects on health and the environment (Li et al., 2022). To address these challenges, researchers propose tagging nanoproducts for easier separation and recovery. They emphasize the need for collaboration among all stakeholders to develop comprehensive regulations and conduct life cycle assessments of NPs, therefore, better understand their long-term environmental impacts (Chowdhury et al., 2022).

Conclusions and Prospects

Over the past century, extensive research on nanomaterials has highlighted their significant potential across various fields, including agriculture. Nanotechnology (NT) is emerging as a critical tool for enhancing agricultural productivity, with promising applications in pesticide delivery, biopesticides, fertilizers, and soil reclamation. The studies reviewed herein demonstrate the efficacy of these materials in improving soil structure and stability. Key factors such as the size and microstructure of NPs have been identified as essential contributors to enhancing soil strength. Moreover, the widespread availability of NPs—including clays, silica, calcium carbonate, and zeolite—coupled with their cost-effectiveness, positions them as economically viable options for large-scale agricultural use. Their eco-friendly characteristics further support their role in sustainable agricultural practices, striking a balance between technological advancement and environmental conservation.

However, despite these promising developments, research focusing on the application of NT to improve the physical properties of agricultural soils remains limited. Comprehensive investigations are needed to understand how NPs interact with natural ecosystems, including soil texture, moisture content, pH levels, and nutrients, to ensure that their application does not inadvertently lead to environmental degradation or demonstrate diminished effectiveness. Large-scale, long-term studies are crucial to identifying the specific properties of NPs that can enhance agricultural soils while assessing their potential health and environmental impacts. Although the reviewed studies reported no immediate toxic hazards, there remains a possibility that certain NPs could pose risks by entering biological systems, particularly through inhalation.

From an economic perspective, the scalability of NPs in agriculture will depend on production costs, market availability, and long-term benefits. While initial investments in NT can be substantial, the potential for increased crop yields, improved soil health, and reduced reliance on conventional agrochemicals may justify these costs over time. Sustainable practices in the development and deployment of NPs will be vital to ensuring that economic benefits are realized without compromising environmental integrity. The widespread adoption of NT in agriculture will require clear regulatory frameworks, robust economic models, and thorough sustainability assessments.

Ultimately, while NT holds great promise for transforming agricultural practices, long-term research is essential to fully understand its impacts. Future studies should prioritize not only the efficacy and safety of NPs but also their economic viability and environmental sustainability. Additionally, developing robust methods for assessing occupational exposure and potential toxicity is critical for minimizing health risks. By addressing these challenges, NT can play a pivotal role in advancing sustainable agriculture, providing solutions that are both economically feasible and environmentally responsible.