From Contamination to Mitigation: Addressing Cadmium Pollution in Agricultural Soils

Abstract

Cadmium (Cd) contamination in agricultural soils originates mainly from atmospheric deposition, irrigation water, fertilizers, pesticides, and industrial waste discharges. This human-induced pollution adversely affects soil fertility and structure, disrupts plant growth and physiological activities, and poses severe health risks through food-chain accumulation. Despite increasing research attention, comprehensive assessments that integrate global patterns, remediation strategies, and knowledge gaps remain limited. Therefore, this literature review critically synthesizes findings from 1060 peer-reviewed studies (screened using PRISMA guidelines) retrieved from Scopus and Web of Science databases, focusing on Cd sources, environmental behavior, plant responses, and soil remediation techniques. Results show that most research has been concentrated in Asia—particularly China—and Latin America. The most frequently investigated topics include Cd accumulation in crops, soil amendments, phytoremediation, and microbial-assisted remediation. Among remediation strategies, assisted phytoremediation and integrated biological–chemical approaches (biochar, PGPR, and soil amendments) emerged as the most promising for sustainable Cd mitigation. In conclusion, this review highlights regional disparities in research coverage, emphasizes the effectiveness of combined remediation approaches, and identifies the need for interdisciplinary and field-scale studies to advance sustainable solutions for Cd pollution control in agricultural systems.

1. Introduction

The expansion of urban areas, the intensification of agricultural activities and industrialization contribute significantly to the increase in anthropogenic emissions, which contribute to soil pollution by heavy metals such as arsenic, Cd, mercury and lead. Long-term use of phosphate fertilizers [1,2], pesticides and sewage sludge [3] contributes to the accumulation of Cd (Cd) in agricultural soils. Cadmium (Cd) is particularly concerning due to its high mobility in soils, strong bioavailability, persistence in agricultural environments, and notable toxicity and non-biodegradability [4,5]. These properties contribute to its prolonged presence in the environment, highlighting the importance of monitoring and mitigation strategies. So far, a lot of research has been carried out on soil pollution [6] with Cd and its accumulation in plants [7].

Heavy metal pollution, particularly Cd, represents a significant global problem in agricultural regions [8]. Among heavy metals, Cd is of particular concern because of its high mobility in soils and its ability to accumulate in crops, which indirectly affects human health. Epidemiological studies suggest that Cd exposure may increase the risk of several chronic and neurodegenerative conditions, including cancer, osteoporosis, and disorders of the central nervous system such as Parkinson’s and Alzheimer’s diseases [9]. The strategies currently being addressed for the identification, evaluation and monitoring of soils polluted with heavy metals differ according to the level of industrialization and economic development of the countries where studies are conducted, the agricultural practices used and the financial resources available.

There are numerous connections between the presence of pollutants such as Cd in the soil and the physiological and biochemical characteristics of agricultural and forestry plants that grow in Cd-contaminated soils [10,11,12,13,14,15,16]. These interactions are largely detrimental, as Cd toxicity can impair plant growth, reduce nutrient uptake, and ultimately lower crop productivity [17,18,19,20].

Moreover, climate change acts as a stress multiplier for agricultural systems, further exacerbating soil contamination issues. Altered precipitation patterns, rising temperatures, and the increasing frequency and intensity of extreme events influence water resources and soil dynamics [21,22]. These processes can intensify soil erosion and runoff, promoting the redistribution of pollutants within the landscape [23,24]. Forest ecosystems play a crucial role in mitigating these effects by regulating the water cycle and preventing soil erosion. However, climate change impacts on forests—such as drought-induced tree mortality—reduce their ability to perform these protective functions [25,26,27,28]. Consequently, reduced forest cover and enhanced erosion can facilitate the mobilization and deposition of Cd and other contaminants into agricultural soils, increasing Cd concentrations and aggravating the risks associated with its accumulation in the food chain. Although previous review articles have addressed agricultural soils [29,30,31] or the presence of Cd in soil and plants [32,33,34], to our knowledge, no review has specifically focused on cadmium-contaminated agricultural soils. Therefore, the aim of this study was to evaluate current monitoring, assessment, and remediation strategies addressing Cd pollution in soils and its accumulation in different plant species. Additionally, we sought to identify and classify the regions where most research on the management and control of Cd in soils and plants has been conducted, as well as the indexed journals that cover environmental pollution by heavy metals.

This study identified 1060 scientific articles on Cd contamination in agricultural soils, revealing that most research is concentrated in Asia, especially China, and focuses on phytoremediation, microbial-assisted remediation, and soil amendments. The findings show an increasing global trend in Cd-related research and highlight integrated approaches as the most promising strategies for remediation. The structure of this paper is as follows: Section 2 describes the materials and methods used in data collection and analysis; Section 3 presents the results of the bibliometric and content reviews; Section 4 discusses the main findings and trends; Section 5 summarizes the conclusions and implications for future research.

2. Materials and Methods

This investigation was structured into two complementary phases. The first phase consisted of a bibliometric study designed to explore global research dynamics concerning Cd contamination in agricultural soils. Relevant publications were retrieved from two major bibliographic databases: Scopus and the Science Citation Index Expanded (SCI-Expanded) within Web of Science (WoS). The search query combined the keywords “agricultural soils polluted with Cd”, ensuring a comprehensive coverage of studies aligned with the research focus. Bibliometric approaches were selected due to their robustness in mapping scientific productivity, detecting research trends, and identifying emerging thematic areas. This investigation was structured into two complementary phases. The first phase consisted of a bibliometric study designed to explore global research dynamics concerning Cd contamination in agricultural soils. Relevant publications were retrieved from two major bibliographic databases: Scopus and the Science Citation Index Expanded (SCI-Expanded) within Web of Science (WoS). The search query combined the keywords “agricultural soils polluted with cadmium”, ensuring a comprehensive coverage of studies aligned with the research focus. The bibliometric phase was conducted prior to the qualitative content review in order to establish a data-driven understanding of the research landscape and identify prevailing trends, influential contributors, and thematic clusters. This systematic mapping provided an empirical foundation for the subsequent qualitative phase, guiding the selection and interpretation of literature to ensure analytical depth and relevance. Bibliometric approaches were selected due to their robustness in quantitatively mapping scientific productivity, detecting research trends, and identifying emerging thematic areas across disciplines [35,36]. These characteristics make them particularly suitable for contextualizing complex environmental issues such as Cd pollution in agricultural soils, where research is dispersed across multiple scientific domains.

Following data collection, the screening and refinement of records adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [37]. The initial query yielded 1424 records (787 from Scopus and 637 from WoS). After eliminating 246 duplicates, 1178 unique publications were retained. A two-stage screening was then applied based on pre-established inclusion and exclusion criteria. The inclusion criteria focused on peer-reviewed studies addressing cadmium contamination, assessment, or remediation in agricultural soils, published in English, and providing sufficient bibliographic information. Publications were excluded if they were irrelevant to the scope, non-peer-reviewed, unpublished, missing abstracts, or classified as editorials or correspondence. This rationale ensured that only scientifically sound and thematically relevant records were included for bibliometric and content analyses. This process excluded 12 manually filtered entries, 9 inaccessible documents, 8 without abstracts, and 89 unrelated records. Ultimately, 1060 articles were deemed eligible for bibliometric and content analyses (Figure 1).

The bibliometric assessment considered ten analytical dimensions: (1) Publication type; (2) Research discipline; (3) Year of publication; (4) Geographic distribution of contributions; (5) Authorship; (6) Institutional affiliations; (7) Language of publication; (8) Journals; (9) Publishers; (10) Keywords.

Data analysis and visualization were performed using Web of Science Core Collection (version 5.35, Clarivate) [38], Scopus [39], Microsoft Excel (version 2024) [40], and Geochart [41]. To further explore bibliometric relationships, VOSviewer (version 1.6.20) [42] was applied for mapping co-authorship networks, co-citation patterns, and keyword co-occurrence clusters.

The second phase consisted of a qualitative content review of the 1060 screened publications. This stage enabled a deeper examination of knowledge production on the subject and facilitated the categorization of findings into five thematic domains (Figure 2): (1) Research trends on Cd contamination in agricultural soils; (2) Country-specific case studies; (3) Effects of Cd exposure on plant growth, physiology, and phytoremediation potential; (4) Soil remediation strategies for Cd contamination; (5) Techniques for mitigating Cd accumulation in crops.

Over 1000 publications were screened during the preparation of this review. Of these, 185 studies were directly relevant to the topic and are cited in the reference list.

3. Results

3.1. Qualitative Review of Literature

In summary, the bibliometric analysis revealed a growing global interest in Cd pollution of agricultural soils, with a significant rise in publications after 2010. Most studies have been conducted in Asia, particularly in China, which dominates the field in terms of authorship and institutional contributions. Research has been published mainly in environmental and agricultural journals, focusing on topics such as Cd accumulation, heavy metal contamination, and soil remediation. The keyword evolution also highlights a shift from general heavy-metal pollution studies toward more targeted investigations on Cd’s effects and innovative mitigation approaches.

From the bibliometric analysis conducted, we identified a total of 1060 publications related to agricultural soils polluted with Cd. Of these, most are research articles (949, representing 90% of the total), followed by 58 reviews (5%), 42 proceedings papers (4%), and 11 book chapters (1%) (Figure 3). Highlighting these categories provides insight into the development stage and evolving research focus within this field. The predominance of research articles reflects the extensive empirical investigations conducted to understand Cd behavior, risk assessment, and remediation strategies in agricultural contexts. Review articles synthesize these findings, supporting comprehensive evaluations of mitigation approaches, while proceedings and book chapters indicate emerging topics and interdisciplinary discussions relevant to ongoing policy and management frameworks. Together, these publication types collectively support the objectives of this study by mapping the scope, depth, and evolution of Cd-related research in agricultural soils.

The evolution of the number of publications over the years is shown in Figure 4. A steady increase in the number of published articles can be observed, particularly after 2010, when their number began to double every five years. This growth likely reflects the rising global awareness of heavy metal pollution, the development of advanced analytical techniques, and the implementation of stricter environmental regulations and sustainability policies that have driven scientific and policy interest in Cd contamination.

The classification of published articles by research areas, according to the Web of Science Core Collection, highlights the predominance of the following out of 34 categories: Environmental Sciences (413 articles), Agriculture (106 articles), Engineering (84 articles), and Plant Sciences (67 articles) (Figure 5).

The authors of these publications come from 88 countries across all inhabited continents (Figure 6). By far, China has published the highest number of articles (293), followed by Pakistan (50), the USA (45), and India (41).

The authors’ countries of origin, who have published articles on this topic, can be organized into three clusters, each comprising at least seven countries. These clusters are as follows: Cluster 1 includes: China, Argentina, Belgium, England, Germany, Nigeria, Poland, Romania, Scotland, South Africa and Turkey; Cluster 2 consists of Australia, Austria, Bangladesh, Canada, Ghana, Japan and Slovakia; Cluster 3 consists of Brazil, Czech Republic, Denmark, France, Iran, Italy and Switzerland; (Figure 7). Since each cluster includes countries from different continents, no clear geographical pattern of grouping could be identified; it seems that connections between authors are the main factor driving these associations.

The publications on this topic have appeared in a wide range of scientific journals (237 in total). The most prominent among them were Science of the Total Environment (with 26 articles), Environment Science and Pollution Research (with 39 articles), Ecotoxicology and Environmental Safety and Environmental Pollution (with 20 articles each), (

Table 1. The leading journals that have published articles on the studied topic.

Serial Number	Journal	Documents	Citations	Total Link Strength *
1	Science of the Total Environment	41	4513	74
2	Environment Science and Pollution research	39	1152	34
3	Ecotoxicology and Environmental Safety	20	1052	27
4	Journal of Hazardous Material	16	930	25
5	International Journal of Phytoremediation	17	320	23
6	Environmental Pollution	20	1404	22
7	Chemosphere	13	1169	12
8	Environmental Geochemistry and Health	15	278	12
9	Environmental Monitoring and Assessment	17	452	10
10	Sustainability	13	95	10
11	Agronomy	8	217	7
12	Plant and Soil	7	551	7

* Total Link Strength indicates the cumulative strength of co-citation links between articles in the journal.

and Figure 8).

In terms of institutional affiliation, the most representative institutions for authors publishing on this topic were: the Chinese Academy of Sciences (74 articles), Nanjing Institute for soil science (34 articles), Egyptian Knowledge Bank (27 articles) and University of Chinese Academy of Sciences (26 articles). The leading publishers in this research domain included Elsevier (193 articles), Springer Nature (153 articles), MDPI (59 articles) and Taylor & Francis (56 articles).

From the multitude of keywords used in the published articles, the most frequently encountered were cadmium, heavy metals, accumulation, and agricultural soils (

Table 2. The most frequently occurring keywords in studied articles.

Serial Number	Keyword	Occurrences	Total Link Strength
1	Cd	338	1496
2	heavy metals	324	1385
3	accumulation	148	714
4	lead	110	548
5	agricultural soils	112	527
6	zinc	87	450
7	phytoremediation	96	438
8	contamination	85	377
9	plants	67	332
10	pollution	76	323
11	contaminated soils	63	319
12	bioavailability	55	297
13	toxicity	59	277
14	copper	56	264
15	phytoextraction	51	256
16	remediation	46	218

).

When grouped into clusters, the keywords formed three main categories: Cluster 1, includes terms specific to our search: agricultural soils, health risks, heavy metals, pollution, sediments, soils, spatial distribution; Cluster 2, generally includes terms related to Cd accumulation and its toxicity: accumulation, bioaccumulation, phytoextraction, phytoremediation, tolerance, toxicity; Cluster 3, includes keywords related to the mode of action of this toxic: adsorption, availability (Figure 9).

The evolution of keyword usage over time comprises three stages: between 2016 and 2017, the most common keywords were related to heavy metals associated with Cd in the publications (lead, copper, zinc); between 2017 and 2019, keywords were mainly linked to their effects and remediation (bioavailability, phytoremediation, contamination, tolerance, soil pollution); between 2019 and 2020, the focus shifted to more recent research aspects regarding Cd’s impact—particularly on rice—and modern remediation methods for polluted soils (risk assessment, rice, biochar, toxicity, growth, health risk) (Figure 10).

3.2. Literature Review

In summary, the literature review showed that Cd contamination in agricultural soils is a complex global issue affecting soil health, plant productivity, and human well-being. The reviewed studies emphasized geographic disparities, with Asia being the most researched region, and identified a wide range of remediation strategies, including phytoremediation, microbial assistance, soil amendments, and integrated approaches. Overall, the evidence suggests that while significant progress has been made in understanding Cd dynamics, continued interdisciplinary efforts are needed to develop scalable, sustainable solutions for cadmium mitigation in agricultural systems.

3.2.1. Research Trends on Cd Pollution in Agricultural Soils

Across the numerous articles published on this topic, a wide range of aspects has been studied. Some of these are presented in

Table 3. Main research aspects analyzed in scientific articles of the studied topic.

Current Number	Generic Research Aspect	Representative Studies (Country, Citation)	Number of Studies
1	Cadmium accumulation and plant response	China [43,44,45,46,47,48]; Georgia [49]; Ethiopia [50]	8
2	Soil amendment and immobilization techniques	China [47,48,51,52,53]; Czech Republic [54]; Turkey [55]; Switzerland [56,57]; USA [58]	6
3	Microbial and biochemical responses	China [59]; Turkey [55,60]	3
4	Human exposure and health effects	Japan [61]; China [62]; Jamaica [63]	3
5	Modeling and environmental assessment	Iran [64]; Australia [65]; Belgium [66]; USA [58]; China [67]; general [68]; New Zealand [69]	7

.

The review of 27 selected articles highlights the broad range of research efforts directed toward understanding Cd (Cd) behavior in agricultural soils and its ecological and health implications. Studies have been conducted across multiple continents, with a strong focus on China, reflecting the country’s extensive agricultural activity and severe Cd-related challenges. The research spans diverse aspects, including Cd accumulation and uptake in food crops such as rice, maize, potato, and eggplant [43,44,50], soil processes such as adsorption, desorption, and mobilization [42,47], and the impact on microbial communities [59,67].

Several studies explored remediation strategies, such as phytoremediation using willow, maize, and Solanum species [56,69], soil amendments including zeolite, biochar, and vermicompost [53,54,55], and immobilization techniques using Al-montmorillonite [56]. Human health risks associated with Cd transfer through crops and irrigation practices were also reported from Japan, China, and Jamaica [61,62,63]. More recently, emerging tools such as artificial intelligence have been used to estimate Cd concentrations in soils [64].

3.2.2. Country Case Studies of Cd in Agricultural Soils

A broad range of Cd concentrations has been reported in environmental matrices across different countries. Average Cd values (mg/kg) were found in rocks (92, Idaho; 38, North Carolina), coal (3.8, China; 0.28, India), and groundwater (0.98, China; 0.8, Bangladesh; 0.3, India; 0.16, Egypt). Soil concentrations were reported as 6.3 in Nigeria, 2.5 in Ecuador, 0.8 in Selangor, and 5.0 in Kelantan. Cd levels in fertilizers varied widely, with 5 in China, 192 in the USA, 11 in Morocco, 8.7 in Iran, and 14 in Algeria. Wastewater concentrations reached 20 in Pakistan, 37 in India, and 1.7 in China. Plant Cd contents included 0.81 in Nigeria, 1.2 in Pakistan, and 0.05 in Romania [70,71,72,73,74,75,76,77,78,79]. These examples were selected as they represent geographically diverse regions with varying degrees of industrialization, agricultural intensity, and regulatory control, providing a broad overview of Cd distribution patterns across environmental matrices.

In China, soils near heavy metal–contaminated irrigation areas showed significant Cd accumulation. Approximately 95.5% of soil samples exceeded the national screening value, with irrigation water (56.95%) and atmospheric deposition (42.53%) identified as the main Cd input sources. Mass balance estimations indicated an annual topsoil Cd increase of 2.46 µg kg−1, suggesting a long-term accumulation trend [71,80,81]. To mitigate Cd uptake in rice, molecular breeding has produced low-Cd-accumulation varieties such as OsNRAMP5 null mutants, achieving over 93% reduction in grain Cd concentration—an approach showing strong potential for Chinese rice production [72,82].

In Taiwan, Cd pollution has been recognized since the 1970s, affecting over 200 hectares of farmland and rice paddies. The main source was wastewater discharge from cadmium stearate factories. Government interventions since the 1980s, including factory closures and process modifications, have reduced emissions, though occasional pollution incidents persist [73,83]. Geostatistical modeling using kriging revealed widespread topsoil contamination in Changhua County, with Cd hotspots between 10 and 600 mg/kg, exceeding health-based thresholds [74].

In India, soils affected by industrial activities and long-term fertilizer use displayed elevated Cd concentrations. Industrial soils contained the highest Cd levels, followed by agricultural and roadside soils. Continuous application of phosphate fertilizers and industrial wastes contributed significantly to topsoil contamination, with average concentrations exceeding national guideline values. Cd distribution was strongly influenced by soil pH and seasonal variations [75,84,85].

In Pakistan, effluent-irrigated soils showed a 248–260% increase in Cd content compared to tube well and canal-irrigated soils, primarily due to the use of untreated or partially treated industrial and domestic wastewater, which often contains elevated Cd concentrations. Cd accumulated predominantly in the upper 30 cm of soil, indicating limited vertical mobility. Crop uptake varied with species, with the highest Cd content recorded in chickpea seeds (0.177 mg/kg) and the lowest in wheat seeds (0.034 mg/kg). Among shoots, mung bean accumulated more Cd (0.62 mg/kg) than wheat, reflecting differences in root absorption capacity and translocation efficiency. The general order of seed Cd accumulation under wastewater irrigation was chickpea > maize > mung bean > wheat [76].

In Peru, cacao-growing soils across four agricultural regions showed variable Cd concentrations. Neither cacao variety (Theobroma cacao), cultivation year, nor management practices were directly associated with Cd levels. Both natural and anthropogenic factors contributed to Cd accumulation, highlighting the need to integrate land management with Cd monitoring for sustainable cacao production [77].

In Ecuador, a nationwide survey revealed total soil Cd levels averaging 0.44 mg kg⁻¹, characteristic of young and non-polluted soils. High Cd accumulation in cacao beans was attributed to strong plant uptake capacity combined with cultivation on geologically young soils. Suggested mitigation strategies included soil amendments to reduce Cd bioavailability [78].

3.2.3. Effects of Cd Contamination on Plant Growth, Physiology, and Phytoremediation Potential

Cd (Cd) contamination in soils exerts detrimental effects on plants, with severity depending on concentration and exposure time. Cd interferes with enzymatic and photosynthetic processes, induces membrane damage, and reduces seed germination and overall growth. At higher concentrations, Cd disrupts nutrient and water balance, enhances oxidative stress, and alters photosynthetic structures, ultimately reducing crop yield [79].

In parsley (Petroselinum crispum), widely consumed for its nutraceutical properties in Lebanon, Cd accumulation increased proportionally with soil Cd concentration, with roots showing greater accumulation than shoots. This elevated Cd exposure triggered distinct physiological responses: a marked reduction in shoot and total fresh weights as well as in chlorophyll a, b, and total chlorophyll contents, indicating photosynthetic inhibition. Conversely, increased soluble sugars and amino acids reflected stress adaptation mechanisms. These physiological alterations corresponded to increased Cd uptake and internal redistribution, as confirmed by bioconcentration and translocation factor values, establishing a clear link between Cd exposure, physiological stress responses, and accumulation behavior [80].

Celery and parsley demonstrated distinct responses to Cd exposure. Celery showed strong phytoextraction ability (99.9 µg/g Cd dry weight) and a high tolerance capacity linked to efficient antioxidative defenses. However, risk assessment revealed potential human health hazards (hazard index, HI, and carcinogenic risk, CR) through chronic consumption of contaminated herbs [81].

In maize (Zea mays), Cd toxicity reduced growth, photosynthetic gas exchange, sugar content, ascorbate–glutathione (ASA–GSH) cycle activity, cellular integrity, and proline metabolism. Simultaneously, Cd increased oxidative stress markers, antioxidants, and gene expression linked to stress response [82].

Sorghum (Sorghum bicolor) inoculated with Streptomyces pactum (Act12) and grown in Cd-contaminated soils showed reduced Cd uptake in shoots and roots due to biochar application, suggesting biochar-mediated adsorption as a mitigation strategy [83].

Screening of wild plant species revealed varying bioaccumulation potentials. Among Limnocharis flava, Colocasia esculenta, Ipomoea fistulosa, Commelina benghalensis, and Eichhornia crassipes, Colocasia esculenta displayed significant Cd accumulation, identifying it as a candidate for phytoremediation of contaminated sites, including mining areas and agricultural lands [84].

Mung bean (Vigna radiata) seedlings exposed to increasing Cd stress displayed reductions in growth parameters, photosynthetic pigments (chlorophyll a, b, carotenoids), soluble proteins, and free amino acids. In contrast, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and electrolyte leakage (EL) increased, indicating oxidative stress. Antioxidant activities (ascorbic acid, catalase, ascorbate peroxidase, and peroxidase) were also upregulated with Cd exposure [85].

In sweet potato (Ipomoea batatas), the coexistence of microplastics (MPs) and Cd was evaluated. Hydroponic experiments showed that original polyethylene (PE) MPs enhanced P, K, and Cd adsorption more strongly than weathered MPs. Cd increased accumulation of original MPs in root cortex while decreasing their accumulation in shoots, highlighting complex interactions between MPs and heavy metals in plant systems [86].

Wheat (Triticum aestivum) cultivated in salt-affected soils contaminated with Cd exhibited decreased plant height and reduced straw and grain yield. Simultaneously, Cd concentrations increased in both straw and grain, demonstrating enhanced Cd bioavailability in stressed soils [87].

In marigold (Calendula officinalis), Cd accumulation from polluted irrigation water compromised growth and quality. However, application of plant growth-promoting rhizobacteria (PGPR) strains facilitated both Cd remediation and healthy marigold flower production, supporting multifunctional applications such as urban vertical farming in Cd-contaminated soils [88].

3.2.4. Remediation of Soils Contaminated with Cd

Phytoremediation

Phytoremediation has emerged as one of the most promising approaches for mitigating Cd (Cd) toxicity in soils and has attracted increasing attention over the last decade. This strategy uses plants to extract, stabilize, or transform contaminants in soils, thereby reducing their concentration and mobility. Particular focus has been given to hyperaccumulator species, which can absorb and translocate elevated Cd levels into their aerial tissues without severe growth inhibition. These plants are considered ideal candidates for phytoextraction technologies [89].

Different plant and microbial species have been investigated for their potential to enhance Cd remediation through direct accumulation or by increasing Cd bioavailability. For instance, the yeast Saccharomyces cerevisiae, when applied as a pre-cultured biosorbent medium to Cd-contaminated soils, demonstrated Cd removal efficiencies between 65 and 82% within 30 days at pH 5.5 [75]. In combination with this microbial treatment, plants such as Brassica juncea (Indian mustard) have been shown to accumulate Cd efficiently, enhancing overall remediation.

Crop rotation systems such as Cichorium intybus (chicory)—Nicotiana tabacum (tobacco)—Arachis hypogaea (peanut) have also shown effectiveness in Cd removal under field conditions [90]. Similarly, field experiments confirmed that Sedum plumbizincicola can achieve high remediation efficiencies, particularly when intercropped with Zea mays (maize), combining food production with soil decontamination [91].

Other species, including Rorippa globosa, have been reported as efficient Cd hyperaccumulators suitable for both moderately and highly contaminated soils, especially when glutathione-assisted strategies are employed [92]. Screening experiments revealed that Humulus scandens, Trifolium repens (white clover), and Fanzha (Pueraria montana var. lobata) are tolerant to Cd stress, with accumulation coefficients ranging from 1.19 to 4.08, although Pueraria’s low biomass may limit large-scale application [93].

Despite their potential, hyperaccumulator species are generally limited by low biomass and slow growth, which restrict large-scale phytoextraction. To address this, assisted phytoextraction methods are being developed, involving plant trait modifications or the addition of external substances—such as chelating agents (e.g., EDTA, citric acid), plant growth regulators, or soil amendments (e.g., biochar, compost, or nanoparticles)—to enhance Cd uptake and improve plant tolerance [94,95,96].

An overview of plant species documented for Cd phytoremediation is summarized in

Table 4. Different plant species experimentally tested for phytoremediation of Cd-polluted soils.

Cur. №	Plants Species	Country	Cited by
1	Ageratum conyzoides L.	China	Wang et al., 2023 [97]
2	Amaranthus hypochondriacus L.	China	Wang et al., 2019 [98]
3	Atriplex halimus L.	Greece	Manousaki et al., 2009 [99]
4	Beta vulgaris var. cicla L.	China	Tan et al., 2020 [100]
5	Brassica juncea L.	China	Wang et al., 2022 [101]
6	Brassica napus L.	Bangladesh	Sultana et al., 2024 [102]
7	Brassica oleracea L.	China	Ma et al., 2021 [103]
8	Brassica parachinensis L.	China	Qiu et al., 2011 [104]
9	Celosia argentea L.	China	Yu et al., 2024 [105]
10	Chenopodium album L.	India	Kumar et al., 2024 [106]
11	Chrysanthemum indicum L.	China	Lu et al., 2025 [107]
12	Helianthus petiolaris Nutt.	Belgium	Saran et al., 2020 [108]
13	Morus alba L.	China	Jiang et al., 2019 [109]
14	Ocimum gratissimum L.	Thailand	Prapagdee and Khonsue, 2015 [110]
15	Phragmites australis (Cav.) Trin. Ex Steud.	Iran	Nezhad et al., 2012 [111]
16	Populus tremula L.	Belgium	Van Nevel et al., 2011 [112]
17	Ricinus communis L.	India; China	Bauddh et al., 2016; Sun et al., 2018 [113,114]
18	Rorippa globosa Turcz.	China	Dou et al., 2019 [92]
19	Salix × aureo-pendula CL ‘J1011’	China	Li et al., 2010 [115]
20	Salix caprea L.	Austria	Wieshammer et al., 2007 [116]
21	Sedum plumbizincicola	China	Deng et al., 2016 [91]
22	Silybum marianum (L.) Gaertn.	Greece	Papadimou et al., 2024 [117]
23	Solanum lycopersicum L.	Saudi Arabia	Alamer et al., 2022 [118]
24	Solanum melongena L.	Saudi Arabia	Alamer et al., 2022 [118]
25	Solanum nigrum L.	China	Ji et al., 2011; Yin et al., 2014 [119,120]
26	Sorghum bicolor (L.) Moench	China	Xiao et al., 2021 [121]
27	Thlaspi caerulescens (J.Presl & C.Presl) F.K. Mey.	France	Saison et al., 2004 [122]
28	Nicotiana tobaccum L.	China	Tan et al., 2020 [100]

, highlighting their geographic origins and sources of citation.

Microorganisms

Microbial-assisted remediation has been increasingly explored as an alternative or complement to plant-based strategies. Soil microorganisms can immobilize or transform Cd, thereby reducing its transfer from soil to crops. For instance, several microorganisms, including one fungus, two actinomycetes, and two bacteria, were isolated from Cd-contaminated soils, with one actinomycete and a Bacillus strain showing particularly high biosorption potential [123].

A Cd-resistant bacterium, Pseudomonas putida strain B14, has been identified with the bioprecipitation capacity of Cd and Zn ions, suggesting its utility for bioremediation in soils and wastewaters. Plant growth-promoting rhizobacteria (PGPR), such as P. putida and P. fluorescens, have demonstrated dual roles in enhancing crop growth (Brassica juncea) and reducing Cd stress, making them a sustainable alternative to chemical fertilizers [124].

In cocoa-growing regions of Colombia, microbial community studies revealed Cd-tolerant strains that may help reduce Cd uptake in cocoa plants, providing significant implications for the chocolate industry [125]. Biochar-immobilized Cd-resistant bacteria (CRB) have also been shown to improve Cd phytoextraction efficiency in ornamental species such as Chlorophytum laxum. Additionally, co-inoculation of Trichoderma harzianum with native soil microbes enhanced Cd tolerance and uptake in barley, supporting its application for remediating heavily polluted soils [126].

Amendments

Soil amendments represent another major approach for reducing Cd mobility and bioavailability. Application of sepiolite at a 5% rate decreased Cd in the acid-soluble fraction by 42.8% while increasing its residual fraction by 35.8%, effectively lowering Cd phytoavailability [127]. Biochar soil amendment (BSA) at rates of 20–40 t ha⁻¹ significantly reduced Cd levels in rice grains (20–90%) across field sites in South China, ensuring food safety thresholds were met [128].

In Europe, lime amendments in paddy fields also proved effective in lowering Cd bioavailability, while compost alone showed limited benefits [129]. More recently, sunflower bottom ash (SBA), with high potassium content and low heavy metal levels, has been identified as a potential amendment for Cd-polluted farmland [130]. Other novel biochar sources, including oil tea shell, reed straw, and urban sludge, have been investigated for similar purposes [131].

Organic Additives

Organic additives (OAs) such as biochar, compost, activated carbon, and plant residues play a critical role in immobilizing Cd in soils through adsorption, complexation, precipitation, and electrostatic interactions [132]. Biochar in particular has been widely studied due to its multifunctional surface properties, which contribute to immobilization mechanisms such as surface complexation, reduction, ion exchange, and π–π interactions [133,134,135].

Rice husk biochar (RHB) prevents Cd leaching into groundwater, reduces plant uptake, and simultaneously enhances soil fertility [136,137,138]. Similarly, vermicomposted green waste improved soil physicochemical properties, nutrient availability, and enzymatic activities, providing a sustainable remediation option [139]. Compost applications were shown to alleviate microbial toxicity under Cd stress, improving key soil quality indicators [140]. Additionally, the application of nano-chelated iron improved crop tolerance and reduced Cd stress in agricultural soils [141].

Electrokinetic Remediation and Geo-Electrochemical Technology

Electrochemical approaches have also been tested for Cd removal. Circulation-enhanced electrokinetic (CEEK) achieved removal efficiencies of up to 91% in agricultural soils in Taiwan, maintaining neutral soil pH during treatment [142]. Similarly, geo-electrochemical technology (GT) applied to paddy fields significantly reduced Cd accumulation in rice tissues and altered Cd transport patterns within plants, offering a novel in situ remediation technique [143].

Combined Methods

Integrated approaches combining biological, organic, and chemical strategies are increasingly being explored to maximize Cd remediation efficiency. Co-application of biochar and microorganisms enhanced crop performance and soil Cd immobilization in soybean and maize systems [144,145]. PGPR combined with nanohybrid fertilizers further reduced Cd bioavailability and supported plant growth [146].

Other promising combinations include heavy metal-immobilizing Enterobacter bugandensis with calcium polypeptides [147], white rot fungi with nanohydroxyapatite (NHAP) [148], and biochar with inorganic agents such as FeSO₄ and manure [149,150]. Moreover, combining biochar with zeolite improved Cd immobilization by providing both adsorption capacity and ion-exchange properties [151].

Finally, bio-organic stabilizing agents composed of biochar, rice straw, lime, and engineered Pseudomonas putida strains demonstrated high cost-effectiveness and strong potential for improving agricultural productivity in Cd-polluted soils [152].

3.2.5. Techniques for Reducing Cd Accumulations in Plants

Several strategies have been explored to reduce Cd (Cd) uptake and accumulation in food crops, with rice and wheat receiving the most attention.

In rice, selenium (Se) supplementation has been reported to mitigate Cd toxicity and restore micronutrient balance in grains, offering a cost-effective, eco-friendly, and sustainable approach for cultivating rice in Cd-polluted soils [153]. In another study, the combined application of silicon (Si) and melatonin (MT) was tested against Cd and arsenic (As) uptake. Results indicated that Si + MT treatment was more effective than Si alone, particularly in high-polluted (HP) soils when applied at the flowering stage, and in low-polluted (LP) soils when applied at the tillering stage. This treatment markedly reduced Cd and As, transport to rice grains [154]. Similarly, nanoscale zero-valent iron (Fe) combined with MT was shown to enhance Cd reduction efficiency by modulating soil chemical and microbial properties [155]. At the genetic level, the rice metal chaperone OsHIPP16 was identified as a detoxification factor, repressing Cd accumulation in rice crops [156].

Agronomic practices also play a crucial role. Foliar spraying with transpiration inhibitor–rhamnolipid reduced Cd levels in rice grains [157]. In contrast, straw incorporation in Cd-contaminated paddies significantly influenced Cd bioavailability and accumulation. Direct incorporation of rice or rape straw was not recommended, whereas co-application with lime effectively decreased Cd accumulation [158].

In wheat, foliar application of ferulic acid (FA) was effective in reducing Cd toxicity and grain accumulation in both hydroponic and field trials, making FA a promising strategy for Cd detoxification [159]. Similarly, mercapto-modified attapulgite (MA) successfully immobilized Cd in alkaline soils, reducing Cd uptake in wheat [160]. Manipulating rhizosphere fungal communities also proved effective: fungicide application (chlorothalonil and benomyl) shifted the rhizosphere microbiome, reducing Cd uptake by promoting Cd-tolerant beneficial fungi such as Rhizopus, while suppressing pathogenic Fusarium [161].

Beyond cereals, phytoremediation approaches have targeted biomass management. Endophytic bacteria were shown to lower Cd content in sunflower stalks without compromising nutrient levels, allowing safer reuse of contaminated biomass as fertilizer [162]. Similarly, inoculation of Brassica rapa with Cd-resistant bacterium Stenotrophomonas sp. CD2 reduced Cd accumulation by over 50% in roots and aerial tissues [163]. In cauliflower (Brassica oleracea), the combined application of Cd-tolerant bacterial consortium (Klebsiella strains) and jasmonic acid (JA) improved growth parameters while reducing Cd uptake into roots [164].

Finally, plant growth-promoting rhizobacteria (PGPR) have emerged as a sustainable and versatile approach to Cd detoxification. Through mechanisms including biosorption, chelation, sequestration, and biotransformation, PGPR not only mitigate Cd stress but also enhance nutrient uptake and crop productivity, highlighting their promise in sustainable agriculture under Cd contamination [165].

4. Discussion

4.1. Bibliometric Review

The majority of publications in this field are research articles, which is consistent with the general trend in scientific literature. As observed in studies on other environmental pollutants [166,167,168,169,170], research articles constitute approximately 90% of all publications. However, review articles and conference papers are also well represented. As in other cases [171,172,173,174,175,176], the number of published articles has followed an exponential growth trend over the past two decades, most likely due to the overall increase in scientific output and the growing interest of researchers in this subject.

Regarding the research areas covered by these publications, the most prevalent ones—Environmental Sciences, Agriculture, and Plant Sciences—are consistent with the scope of the bibliographic query used to retrieve the dataset.

Among the countries where this problem has been studied, China stands out with an exceptionally high number of publications—20 times more than the second-ranking country—as well as the highest number of authors involved. This is largely due to the severe Cd pollution of soils in China [177,178,179]. Another explanatory factor is the Cd contamination of rice, a crop widely cultivated both in China and in other countries with a high publication record on this topic (such as India and Pakistan).

The keywords used in these publications are predominantly focused on the central theme (Cd, heavy metals, accumulation, and agricultural soils). In addition, there is a high frequency of keywords referring to other heavy metals present in soils (lead, zinc, copper), as many authors have analyzed them in parallel with Cd. Keywords related to soil remediation methods (phytoremediation, phytoextraction, remediation) are also common.

The temporal evolution of keyword usage is also insightful: initially dominated by terms associated with heavy metals occurring alongside Cd, later shifting towards effects and remediation strategies, and more recently emphasizing Cd’s impact—particularly on rice—and innovative remediation approaches for polluted soils. This progression reflects not only advances in scientific research and the development of new methodologies but also changes in public awareness and perception of this issue.

4.2. Research Trends on Cd Pollution in Agricultural Soils

The collected studies illustrate that Cd contamination in agricultural soils is a multifaceted issue, affecting crop productivity, soil quality, microbial diversity, and ultimately human health. A notable trend is the concentration of research in Asian countries, particularly China, where high Cd exposure through staple foods such as rice poses significant risks to public health. This geographic clustering reflects both the severity of contamination and strong national research efforts.

From a mechanistic perspective, the literature shows that Cd behavior in soil is highly dependent on factors such as soil pH, organic matter, and amendments. Acidification tends to increase Cd mobilization and plant uptake [66], while amendments like zeolite, biochar, and vermicompost generally mitigate Cd toxicity by immobilization or improving soil structure and enzyme activity [54,55].

Biological solutions, including phytoremediation and the use of biostimulants, demonstrate potential for sustainable Cd management. For instance, maize cultivars and Solanum nigrum show Cd accumulation and remediation capabilities [47,50]. Meanwhile, studies linking Cd exposure to human health effects [61,63] emphasize the importance of translating soil science findings into food safety and public health policies.

Another key trend is the emergence of interdisciplinary approaches, such as artificial intelligence for soil contamination prediction [64], which may enhance monitoring and risk assessment. The combination of traditional agronomic practices, advanced modeling tools, and novel remediation strategies highlights the complexity of tackling Cd pollution but also indicates promising pathways toward safer food systems and healthier soils.

4.3. Country Case Studies of Cd in Agricultural Soils

The case studies presented demonstrate that cadmium contamination in agricultural soils arises from both natural and anthropogenic factors, but its expression differs markedly across countries. Natural sources include parent rock weathering and volcanic emissions [175,176], while anthropogenic contributions mainly result from phosphate fertilizers, wastewater irrigation, industrial emissions, and mining activities [177,178,179].

In China, Cd accumulation is clearly linked to anthropogenic activities such as irrigation with contaminated water and atmospheric deposition [71,178,180]. The annual increase in Cd in topsoil indicates a continuous accumulation trend, and the high proportion of soils exceeding screening values highlights the scale of the issue. However, the development of low-Cd-accumulating rice cultivars illustrates how breeding innovations can offset soil contamination risks and protect food security, even in heavily polluted regions.

In Taiwan, Cd contamination has persisted for decades, primarily driven by emissions from cadmium stearate factories [73]. Despite regulatory actions and industrial closures, spatial analyses still reveal hotspots with Cd levels (10–600 mg/kg) that far exceed safe limits [74]. This indicates that Cd pollution, once established in soils, remains difficult to remediate and that industrial sources leave a lasting legacy in agricultural environments. This persistent legacy arises because Cd binds strongly to soil particles, particularly in clay and organic matter fractions, leading to low mobility and slow natural attenuation rates. In addition, Cd has a long residence time in soils and can be gradually re-mobilized through changes in pH, redox potential, or land-use practices, perpetuating contamination even decades after the original source has been removed. Such characteristics of Cd behavior in soils have been documented in long-term monitoring studies worldwide, underscoring the enduring impact of industrial sources on agricultural landscapes [73,74].

In India, elevated Cd concentrations in soils were closely associated with long-term use of phosphate fertilizers and industrial discharges [75,181]. Seasonal variation and soil pH further influenced Cd distribution, showing how soil chemical conditions interact with human practices to govern Cd dynamics. This suggests that mitigation in India would require both improved fertilizer quality and soil management tailored to local conditions.

In Pakistan, wastewater irrigation caused a sharp increase in soil Cd compared to tube well and canal irrigation [76]. The pattern of crop uptake—greatest in chickpea and lowest in wheat—shows species-specific differences in Cd accumulation. This finding has practical implications: crop selection could help reduce dietary Cd exposure in contaminated areas, at least in the short term [182].

In Peru, cacao-growing soils contained Cd levels influenced by both natural and human factors [75,183]. While soil concentrations were not always extreme, cacao plants efficiently accumulated Cd, highlighting the importance of crop-specific uptake traits in determining food-chain risks.

Similarly, in Ecuador, soils themselves contained relatively low Cd levels (0.44 mg/kg), typical of young soils, yet cacao beans showed high Cd accumulation [76,184]. This again emphasizes that crop physiology—rather than soil concentration alone—can drive contamination of agricultural products and complicate food safety management.

Taken together, these country examples underline that Cd contamination in agricultural systems is not uniform but shaped by the interplay of pollution sources (industrial effluents, fertilizers, wastewater), soil properties, and crop-specific uptake mechanisms. China and Taiwan illustrate the persistence of Cd once introduced into soils, while Pakistan, Peru, and Ecuador demonstrate the importance of crop selection and physiology in mediating risks. In Pakistan, wastewater irrigation represents an agricultural practice that can exacerbate Cd accumulation, highlighting that farming methods themselves can influence contamination levels. India similarly shows how specific agricultural practices can intensify Cd problems over time. These interpretations suggest that solutions must be highly context-specific, combining pollution prevention with crop and soil management strategies adapted to local conditions.

4.4. Plant Responses and Mitigation Strategies to Cd Contamination

The reviewed studies consistently demonstrate that Cd contamination severely hampers plant performance, with impacts ranging from germination inhibition to yield decline. Cd disrupts photosynthesis, impairs enzymatic activity, and promotes oxidative damage, aligning with the general toxicological profile reported in controlled experiments [79,185].

Leafy herbs such as parsley and celery present a dual concern: while they accumulate Cd efficiently—indicating potential for phytoextraction—they pose significant risks to food safety. The increase in sugars and amino acids in parsley suggests adaptive metabolic responses, yet the reduced biomass and chlorophyll highlight compromised productivity [80,81]. The elevated hazard indices and carcinogenic risk values in celery further emphasize the public health risks associated with consuming Cd-contaminated edible plants [81].

Cereal crops such as maize and wheat are not exempt from Cd-induced stress. Both species exhibited impaired growth, photosynthetic inefficiency, and biochemical imbalances [82,87]. In maize, the induction of antioxidative defenses suggests a physiological attempt to mitigate oxidative stress, though it is insufficient to prevent yield loss. In wheat, Cd accumulation in grains highlights its role as a dietary exposure route for humans, exacerbated in salt-affected soils where Cd bioavailability is higher [87].

Legumes such as mung beans displayed similar vulnerability, with reduced photosynthetic pigment levels and increased oxidative markers. The upregulation of antioxidant enzymes underscores a stress-compensation mechanism but does not offset biomass reduction [85].

Root crops, particularly sweet potatoes, present an additional complexity when Cd co-occurs with microplastics. The interaction between Cd and MPs alters nutrient uptake and metal partitioning, pointing to the need for further investigation into combined pollutant effects in agricultural systems [86].

On the other hand, certain species demonstrated phytoremediation potential. Wild plants such as Colocasia esculenta and aquatic macrophytes showed notable Cd bioaccumulation capacity, suggesting a role in rehabilitating contaminated soils and water systems [84]. Similarly, biochar application reduced Cd bioavailability in sorghum, confirming soil amendments as promising remediation strategies [83]. Biotechnological approaches, including inoculation with PGPR, proved effective in marigold, where remediation and sustainable crop production were achieved simultaneously [88].

Overall, while Cd contamination threatens plant growth and food safety across multiple crop types, the reviewed evidence highlights potential remediation pathways—ranging from phytoremediation and biochar amendments to microbial inoculants—that could mitigate risks and support safer agricultural practices.

4.5. Remediation of Soils Contaminated with Cd

The remediation of Cd-contaminated soils remains a critical challenge for sustainable agriculture and food safety. Among the strategies evaluated, phytoremediation has emerged as a particularly promising approach, leveraging plants’ natural capacity to extract, stabilize, or transform contaminants into less harmful forms. Compared to conventional techniques such as soil excavation, chemical immobilization, or washing, phytoremediation offers advantages including lower cost, minimal disturbance to soil structure and fertility, compatibility with agricultural land-use, and the potential for simultaneous biomass production. Additionally, it can be applied over large areas with reduced environmental impact, making it a sustainable and socially acceptable remediation option.

Despite its potential, the availability of Cd hyperaccumulator species is relatively limited. Most are concentrated in five botanical families, with a notable prevalence in the Crassulaceae family, and exhibit region-specific distribution patterns, often associated with historical metal mining areas [96,186]. Over the past decade, considerable progress has been made both domestically and internationally in identifying and characterizing Cd hyperaccumulators suitable for agricultural applications. Notable species such as Sedum plumbizincicola, Rorippa globosa, and Brassica juncea demonstrate significant accumulation potential, though their low biomass and slow growth often constrain large-scale applications [92,93].

To overcome these limitations, assisted phytoextraction strategies have been explored. Approaches such as microbially assisted phytoextraction, agronomic measure-assisted phytoextraction, chelate-assisted phytoextraction, nanotechnology- and CO₂-assisted phytoextraction, as well as integrated approaches, have shown promise in enhancing Cd uptake, tolerance, and overall remediation efficiency [94,96]. The integration of microbial inoculants, such as plant growth-promoting rhizobacteria (PGPR) and Cd-resistant bacteria, with hyperaccumulators not only improves Cd bioavailability but also supports plant growth under metal stress [124,126].

Microbial-assisted remediation further complements phytoremediation by immobilizing or transforming Cd in soils, thereby reducing its bioavailability and transfer to crops. Various bacterial, fungal, and actinomycete strains have demonstrated significant biosorption or bioprecipitation potential. Co-inoculation strategies and biochar immobilization of Cd-resistant microbes have enhanced the efficiency of Cd uptake in both field and greenhouse experiments, highlighting the synergistic potential of biological approaches [144,187].

Soil amendments and organic additives also play pivotal roles in reducing Cd mobility. Amendments such as sepiolite, lime, sunflower bottom ash, and biochar effectively decrease Cd phytoavailability by altering its chemical fractionation or enhancing soil adsorption capacity. Organic amendments like compost, vermicompost, and rice husk biochar not only immobilize Cd but also improve soil fertility and enzymatic activity, thereby supporting sustainable crop production [127,139].

Advanced technologies, including electrokinetic remediation and geo-electrochemical approaches, have demonstrated the ability to remove substantial portions of Cd from soils while maintaining soil pH and minimizing environmental disruption. Compared with biological or plant-based remediation, these methods offer faster and more controllable removal of Cd but often require higher energy input, technical expertise, and infrastructure investment. Nevertheless, they provide targeted in situ remediation possibilities for heavily polluted areas where biological approaches alone may be insufficient [142,143].

Conversely, integrated approaches that combine biological, chemical, and physical strategies appear to offer the most robust and sustainable solutions for Cd remediation. For example, the co-application of biochar with microorganisms, PGPR with nanohybrid fertilizers, or biochar with inorganic stabilizers like FeSO₄ has consistently improved Cd immobilization, enhanced crop growth, and increased overall remediation efficiency [145,149,151]. These outcomes can be directly linked to specific mechanisms: adsorption of Cd²⁺ ions on biochar surfaces, complexation with organic and microbial ligands, precipitation of Cd as insoluble sulfates or carbonates in the presence of FeSO₄, and ion exchange between Cd²⁺ and functional groups on soil amendments. Such synergistic mechanisms act concurrently, yielding cost-effective and environmentally sound remediation for contaminated agricultural soils.

In conclusion, the combined evidence supports that while individual approaches—phytoremediation, microbial inoculation, soil amendments, and electrochemical techniques—have inherent benefits, integrated and assisted strategies represent the most effective and scalable solutions for managing Cd pollution in agricultural soils. The continued development of hyperaccumulator-based phytoremediation, particularly when coupled with microbial or chemical assistance, is likely to play a central role in achieving long-term soil decontamination while maintaining agricultural productivity.

4.6. Strategies for Mitigating Cd Accumulation in Food Crops

The collected studies demonstrate a wide array of strategies for reducing Cd accumulation in crops, which can be broadly categorized into (i) nutrient and chemical amendments, (ii) nanomaterials and biostimulants, (iii) genetic and molecular approaches, (iv) agronomic practices, and (v) microbial interventions.

4.6.1. Nutrient and Chemical Amendments

Selenium (Se), silicon (Si), and ferulic acid (FA) supplementation have been shown to alleviate Cd toxicity and restore plant health. The case of Se in rice [153] and FA in wheat [159] highlights the dual role of these amendments: they not only reduce Cd accumulation but also restore or maintain essential nutrient levels in grains. Lime co-application with straw residues further illustrates how soil amendments can modulate Cd bioavailability [158]. These approaches are relatively cost-effective and scalable, but their efficiency may vary depending on soil type and pollution levels.

4.6.2. Nanomaterials and Biostimulants

Nanoscale zero-valent iron (nZVI) and melatonin (MT) represent innovative approaches. The synergistic effect of Si + MT [152] and Fe + MT [155] underscores the importance of combining chemical and biological factors for improved remediation efficiency. While promising, the ecological risks and long-term impacts of nanomaterials require further evaluation before large-scale adoption.

4.6.3. Genetic and Molecular Approaches

The discovery of OsHIPP16 as a Cd-detoxifying chaperone in rice [156] opens new opportunities for genetic engineering or marker-assisted selection of low-Cd crop varieties. However, translating such molecular findings into field-ready applications remains a long-term challenge, given regulatory and acceptance barriers for genetically modified organisms. Likewise, a high genetic diversity and a better implementation of the genetic management principles is mandatory for a higher resilience of the species, as had resulted in forestry [188,189,190,191].

4.6.4. Agronomic Practices

Agronomic practices, such as foliar sprays (rhamnolipid [157] and residue management [158]), offer practical tools for farmers in Cd-contaminated regions. However, these interventions must be adapted to local soil and crop conditions, as the effectiveness of treatments such as straw return depends heavily on pH and pollutant concentrations.

4.6.5. Microbial Interventions

Microbial strategies—including endophytes, PGPR, and fungal community manipulation—emerge as highly promising. Inoculation with Cd-resistant strains (e.g., Stenotrophomonas sp. CD2 [163] or bacterial consortia with JA [164] substantially reduced Cd uptake while enhancing crop growth. PGPR-mediated detoxification [165] presents a sustainable, environmentally friendly alternative to chemical inputs, aligning with circular bioeconomy principles. Importantly, microbial interventions extend beyond soil remediation: endophyte-assisted biomass decontamination [162] addresses the critical issue of safe biomass disposal after phytoremediation.

4.6.6. Towards Integrated Approaches

A key theme across the studies is integration. No single strategy offers a complete solution, but combining soil amendments, microbial inoculants, and agronomic practices appears most effective [192,193,194]. For example, Si + MT treatment showed synergistic effects [154], while lime incorporation with straw improved Cd immobilization [158]. Future work should explore multi-pronged management packages tailored to crop type, soil characteristics, and pollution intensity.

4.6.7. Implications for Sustainable Agriculture

The reviewed studies highlight the potential of eco-friendly, scalable, and farmer-accessible strategies for reducing Cd accumulation in crops. These findings support global food safety initiatives, particularly in regions where Cd contamination threatens staple crops such as rice and wheat. However, more long-term field trials, cost–benefit analyses, and environmental risk assessments are essential before recommending widespread adoption.

4.7. Research Gaps and Future Directions

Despite significant progress in understanding cadmium (Cd) contamination in agricultural soils, several key areas require further investigation and integration. Research has traditionally focused on Cd as a single contaminant, yet in real agroecosystems it coexists with other heavy metals (Pb, Zn, Cu), pesticides, and emerging pollutants such as microplastics and nanomaterials. These interactions can strongly influence Cd mobility, bioavailability, and plant uptake. Furthermore, most studies emphasize rice and wheat, while other important crops—such as maize, pulses, vegetables, and fruits—remain understudied, despite their differing physiological capacities for Cd accumulation.

Advancing mitigation requires developing scalable, cost-effective, and sustainable remediation approaches. Promising techniques such as phytoremediation, biochar application, microbial inoculants, and electrokinetic methods need to be validated under field conditions, with robust life-cycle, cost–benefit, and risk–benefit analyses. In addition, interdisciplinary approaches that link soil science, plant physiology, toxicology, and public health are essential to better quantify the continuum from soil contamination to human exposure and health outcomes. Finally, socio-economic and policy dimensions—such as farmer adoption, agricultural policy incentives, and market-driven food safety measures—must be incorporated to ensure that proposed solutions are practical and widely implementable.

In summary, future research should integrate multi-pollutant interactions, diversify crop coverage including breeding for low-Cd varieties, and combine technical innovation with socio-economic feasibility. Such a holistic approach will enhance both the scientific and practical effectiveness of Cd pollution mitigation in agricultural systems.

5. Conclusions

The discussion in this paper has emphasized the effects of Cd pollution in soils. Notably, most research conducted in Asia has focused on identifying soils contaminated with heavy metals, reflecting the region’s particular attention to monitoring and assessing Cd pollution risks.

The strategies evaluated for soil remediation include: the phytoremediation—leveraging plants’ natural capacity to extract, stabilize, or transform contaminants into less harmful forms (Sedum plumbizincicola, Rorippa globosa, Brassica juncea); integration of microbial inoculants that promote plant growth and Cd-resistant bacteria; soil amendments and organic additives which immobilize Cd and improve the soil fertility and enzymatic activity; electrokinetic remediation and geo-electrochemical approaches which have the ability to remove substantial portions of Cd from soils while maintaining soil pH and minimizing disruption to the environment; combining biological, chemical and physical strategies that offer the most robust solutions for Cd remediation.

From the literature studied, it was found that strategies to reduce Cd accumulation in plants are grouped as follows: nutritional and chemical modifications (Selenium, silicon, and ferulic acid can mitigate Cd toxicity and restore plant health); nanomaterials and biostimulants (nanoscale zero-valent iron and melatonin improve remediation efficiency); genetic and molecular approaches (remain a persistent challenge in the long term, primarily because of regulatory hurdles and societal resistance to genetically modified organisms); agronomic practices (foliar sprays and residue management); and microbial interventions (endophytes, PGPR, and fungal community manipulation).

Further long-term field testing, comprehensive cost–benefit analyses, and thorough environmental risk assessments are needed before these strategies can be widely recommended for adoption by farmers in areas where Cd contamination is a risk.