Search Results (159)

The influence of rootstocks on mineral nutrient composition in the edible tissue of citrus fruits has not been explored so far. This study assessed leaf and juice mineral nutrients of sweet orange (Citrus sinensis (L.) Osbeck) cultivars (‘Pusa Sharad’ and ‘Pusa Round’) grafted onto different rootstocks (‘RLC-6’, ‘C-35’, ‘X-639’, ‘Yamma Mikan’, ‘Soh Sarkar’, ‘RLC-7’, and ‘Jatti Khatti’). Deviation from optimum percentage (DOP) index was employed as an integrative measure to assess leaf mineral nutrient balance for specific scion–rootstock combinations. The relative abundance of leaf mineral nutrients was ranked as follows: Ca > K > P > S > Mg > Na > Fe > Mn > Zn > Cu. Overall, rootstock ‘X-639’ demonstrated superior mineral nutrient uptake efficiency across grafted plants of both scion cultivars, as indicated by higher leaf mineral nutrient concentrations. Juice mineral nutrient concentrations followed the order K (930.87–1362.17 mg L⁻¹), Ca (346.40–651.33 mg L⁻¹), P (116.23–236.97 mg L⁻¹), Mg (64.60–102.50 mg L⁻¹), S (49.35–74.34 mg L⁻¹), Na (25.61–47.88 mg L⁻¹), Fe (4.76–7.92 mg L⁻¹), Zn (1.79–4.34 mg L⁻¹), Mn (0.73–1.62 mg L⁻¹), and Cu (0.41–0.71 mg L⁻¹), indicating distinct differences in the accumulation pattern of macro- and micro-mineral nutrients in the edible tissues across the studied scion–rootstock combinations. Multivariate analysis revealed that the rootstocks significantly influenced juice mineral nutrient levels, indicating rootstock-mediated agronomic biofortification. Rootstock ‘RLC-6’ enhanced juice K levels, and ‘Soh Sarkar’ improved juice Mg contents, while ‘X-639’ improved juice micronutrient (Zn, Mn, Cu) accumulation in both cultivars. This study constitutes the first comprehensive investigation that explicitly evaluates the influence of rootstocks on the enhancement of mineral nutrient content in the edible tissues of citrus fruits. It further elucidates how rootstock selection can indirectly affect dietary mineral intake, thereby highlighting its potential role for improved nutrition. Full article

Magnesium is an essential macronutrient for both plants and humans. However, its availability in agricultural systems and dietary intake has been declining, raising concerns about crop productivity and nutritional security. In plants, magnesium plays a critical role in photosynthesis, enzyme activation, carbohydrate transport, and overall metabolic regulation, while in humans it is required for numerous biochemical processes related to energy metabolism, cardiovascular function, and disease prevention. Long-term studies have reported a 20–30% decrease in magnesium concentrations in fruits and vegetables worldwide, potentially contributing to widespread magnesium deficiency. Soil factors such as acidification, nutrient imbalance, and intensive agricultural practices further limit magnesium availability along the soil–plant–human continuum. This review summarizes the biological importance of magnesium in plants and humans, evaluates the occurrence and causes of magnesium deficiency, and discusses current strategies for improving magnesium nutrition through agronomic and genetic biofortification. It considers even fertilizer management, nano-fertilizers, and alternative magnesium sources such as serpentinite. The review highlights biofortification as a cost-effective and sustainable strategy to enhance crop magnesium concentration and mitigate global magnesium deficiency while emphasizing the need for further research on bioavailability, environmental safety, and long-term agricultural sustainability. Full article

Biofortification of wheat with anthocyanins is a strategy for solving the problem of “hidden hunger” and preventing chronic diseases. In this study, the blue aleurone trititrigia line ‘Istra 116’ is characterized as a new genetic resource for wheat breeding. Field and laboratory assessments (the years 2021–2024) compared its characteristics with the commercial trititrigia variety in ‘Pamyati Lyubimovoy’ and wheat varieties (Triticum aestivum L.). ‘Istra 116’ showed excellent agronomic qualities: a higher coefficient of productive tillering (1.93 versus 1.2), longer spikes (up to 17.5 cm) and grain yield (4.2 t/ha), exceeding the control for trititrigia (2.6 t/ha) and comparable to winter wheat (4.5 t/ha). A laboratory baking assessment confirmed its satisfactory quality (overall score 4.5/5). The blue pigment from the aleurone layer partially passed into the flour, giving the bread a darker crust but retaining the anthocyanins in the finished product. The results position ‘Istra 116’ as a dual-purpose genetic resource: a potential commercial biofortified crop and a valuable donor of the blue aleurone layer trait for traditional wheat breeding, offering a practical way to increase the nutritional value of basic foodstuffs. Full article

The aim of this study was to evaluate the effects of selenium (Se) biofortification on growth, biomass accumulation, and micronutrient composition of industrial hemp (Cannabis sativa L., cv. Finola) microgreens, with emphasis on Se uptake and its distribution among leaves, stems, and roots. Microgreens were subjected to four Se treatments (Se_0, Se_2, Se_4, and Se_6 µmol Se/L), and changes in morphological traits, micronutrient status (Mn, Fe, Cu, Zn), and Se accumulation were assessed. Selenium biofortification had a marked impact on plant morphology and biomass. Stem length decreased by 12–18% under Se treatments compared with the control, whereas root length increased slightly, particularly at Se_2 and Se_4 (up to +6%). Fresh industrial hemp microgreens biomass responded strongly to Se supply, with the highest stem, root, and total fresh mass recorded at Se_4—representing an increase of 15–22% relative to control plants. At the highest Se level (Se_6), biomass declined by approximately 10–14%, indicating potential growth inhibition at excessive Se concentrations. Micronutrient concentrations were significantly affected by Se. Leaf Mn increased from 152 mg kg⁻¹ at Se_0 to 175 mg kg⁻¹ at Se_6 (+15%), while leaf Zn decreased by 20–25% at higher Se exposure. Stems and roots showed similar antagonistic interactions, with Fe and Zn decreasing by up to 30% at elevated Se levels. Conversely, Mn in stems and roots increased with Se up to Se_4, reaching 400 mg kg⁻¹ in roots. Selenium accumulation exhibited a strong linear response to biofortification, with high coefficients of determination (R² = 0.9685–0.9943), confirming predictable and efficient Se uptake. Correlation analysis revealed strong positive associations among biomass-related traits and distinct interactions among micronutrients, especially the near-perfect correlation between Se and Cu in roots (r ≈ 0.99). Overall, industrial hemp microgreens demonstrate potential for selenium biofortification, provided that selenium application levels remain within safe dietary limits. Full article

Inadequate intake of Fe and Zn is prevalent in a large part of the world’s population, and agronomic biofortification has been a strategy to improve the nutritional quality of food and, consequently, the nutrient intake by people. The objective of this study was to evaluate the effects of Fe and Zn concentrations in the nutrient solution on the morphophysiological traits, nutritional quality, and biofortification of two cultivars of baby leaf lettuce in a deep water technique hydroponic system. Two experiments were conducted, one with ‘Vanda’ lettuce (green) and the other with ‘Luminosa’ lettuce (reddish). Six treatments were evaluated, in a 3 × 2 factorial scheme, corresponding to the concentrations of Fe (2.0, 4.0, and 8.0 mg L⁻¹) and Zn (0.06 and 0.24 mg L⁻¹), with four replicates. ‘Vanda’ proved to be more productive, while ‘Luminosa’ has a higher nutraceutical value. The growth traits, yield, and leaf contents of carotenoids and anthocyanins of both cultivars were not influenced by the increase in Fe and Zn concentrations in the nutrient solution. There was a 25% and a 33% increase in the content of phenolic compounds in ‘Vanda’ and ‘Luminosa’, respectively, when the Fe concentration increased from 2 to 8 mg L⁻¹. The Fe content in ‘Vanda’ was influenced only by the Fe concentration in the nutrient solution and increased by 13% between 2 and 8 mg L⁻¹ of Fe. For ‘Luminosa’, there was an interaction, but the highest Fe contents in the shoot were observed with 8 mg L⁻¹ of Fe, which were 24 and 38% higher than those obtained with 2 mg L⁻¹ of Fe at Zn concentrations of 0.06 and 0.24 mg L⁻¹, respectively. The study showed the importance of evaluating the biofortification for cultivars. While ‘Vanda’ baby leaf was biofortified only with Fe, ‘Luminosa’ was biofortified with both micronutrients. Full article

Micronutrient malnutrition persists as a global health burden, while conventional biofortification approaches suffer from low efficiency and environmental trade-offs. This study aimed to develop and evaluate a foliar-applied selenium–zinc nanocomposite (Nano-ZSe, a mixture of zinc ionic fertilizer and nano selenium) for synergistic Se/Zn co-biofortification in Brassica chinensis L., using a controlled pot experiment that integrated physiological, metabolic, molecular, and rhizosphere analyses. Application of Nano-ZSe at 0.18 mg·kg⁻¹ (Based on soil weight) not only increased shoot biomass by 28.4% but also elevated Se and Zn concentrations in edible tissues by 7.00- and 1.66-fold (within the safe limits established for human consumption), respectively, compared to the control. Mechanistically, Nano-ZSe reprogrammed the ascorbate-glutathione redox system and redirected carbon flux through the tricarboxylic acid cycle, suppressing acetyl-CoA biosynthesis and reducing abscisic acid accumulation. This metabolic rewiring promoted stomatal opening, thereby enhancing foliar nutrient uptake. Simultaneously, Nano-ZSe triggered the coordinated upregulation of BcSultr1;1 (a sulfate/selenium transporter) and BcZIP4 (a Zn²⁺ transporter), enabling synchronized translocation and the tissue-level co-accumulation of Se and Zn. Beyond plant physiology, Nano-ZSe improved soil physicochemical properties, enriched rhizosphere microbial diversity, and increased crop yield and economic returns. Collectively, this work demonstrates that nano-enabled dual-nutrient delivery systems can bridge nutritional and agronomic objectives through integrated physiological, molecular, and rhizosphere-mediated mechanisms, offering a scalable and environmentally sustainable pathway toward functional food production and the mitigation of hidden hunger. Full article

Wheat possesses inherently low concentrations and bioavailability of the essential micronutrients (EMis) zinc (Zn), iron (Fe), manganese (Mn), and copper (Cu), limiting its capacity to sufficiently address human nutritional requirements. Biofortification of wheat with EMis through agricultural methods is a strategy aimed at addressing EMi deficiencies in human populations that emphasize cost-effectiveness and sustainability. All EMis are usually applied foliarly as sulfates, which indicates sulfur (S)-assisted biofortification. The formation of EMi complexes provides solubility as well as protection during long-distance transport. Several small molecules are possible candidates as ligands—the S-containing amino acids cysteine and methionine among them—linking EMi homeostasis to S homeostasis, which represents another aspect of S-assisted biofortification. In this study, we delve into the S-assisted agronomic biofortification strategy by applying sulfate micronutrients coupled with a sulfur-containing amino acid and we explore the effect of the selected accompanying cation (Zn, Fe, Mn, or Cu) on the EMi metallome of the grain, along with the biofortification effectiveness, whilst the type of the incorporated surface active agent seems to affect this approach. A field experiment was conducted for two years with durum wheat cultivation subjected to various interventions at the initiation of the dough stage, aiming to biofortify the grain with EMis provided as sulfate salts coupled with cysteine or methionine as potential biofortification enhancers. The mixtures were applied alone or in combination with commercial surfactants of the organosilicon ethoxylate (SiE) type or the alcohol ethoxylate (AE) type. The performance of two relevant preparations, FytoAmino-Bo (FABo) and Phillon, has been studied, too. The interventions affected the accumulation of the EMi metallome into the grains, along with the interactions of the EMis within this metallome. Several interventions increased the EMi metallome of the grain and affected the contribution of each EMi to this metallome. Many interventions have increased Zn and Fe, while they have decreased Mn and Cu. An increase in Zn corresponded (i) to a decrease in Cu, (ii) to an increase or no increase in Fe, and (iii) to a variable change in Mn. Cys increased the metallome by 34% and Zn and Fe within it. ZnSO₄ and FeSO₄ increased the metallome by 5% and 9%, whilst MnSO₄ and CuSO₄ increased the metallome by 36% and 33%, respectively. The additives improved the contribution to increasing the metallome in most cases. Without surfactant, the efficacy ranking proved to be MnSO₄ > CuSO₄ > ZnSO₄ > FeSO₄. The use of SW7 sustained the order CuSO₄ > MnSO₄ > ZnSO₄ > FeSO₄. The use of Saldo switched the order to CuSO₄ > ZnSO₄ > FeSO₄ > MnSO₄. In the case of Phillon, the order was CuSO₄ > FeSO₄ > ZnSO₄ > MnSO₄. The effect of Cys or Met was case-specific. The differentiations in the intensity of both the agronomic performance (grain weight, grain weight per spike, and yield) and the biofortification performance (concentrations vs. accumulations of each EMi within the grain) among the various combinations of EMis and additives are depicted by adopting a grading scale, which highlighted the intensity of the acclimation reaction of the biofortified grain to the applied intervention. Full article

Selenium (Se) is an essential micronutrient for human health, yet its dietary intake is insufficient in many populations worldwide. Agronomic biofortification represents an effective strategy to enrich crops with Se, and Totally Controlled Environment Agriculture (TCEA) provides a reliable platform to evaluate cultivar-specific responses under standardized conditions. This study evaluated the effects of foliar sodium selenate doses of 0, 5, 10, and 15 µM on two basil (Ocimum basilicum L.) cultivars, ‘Fine Verde’ (FV) and ‘Red Rubin’ (RR), in a micro-TCEA system. The yield was not significantly different at 5–10 µM but declined by 21% at 15 µM, particularly for FV. RR out-yielded FV (+14%), whereas FV produced taller shoots. The 5 µM Se concentration did not affect the total chlorophyll content and quantum yield of photosystem II under control conditions. The highest Se dose (15 µM) decreased the chlorophyll content and electron transport rate by 18% and 12%, respectively, while increasing the stomatal conductance (50%) and transpiration rate (120%). The total phenolics content in RR was double that in FV and increased with Se, whereas the NO₃⁻ concentration in RR decreased by 9% at 10 µM. Principal component analysis separated treatments by Se dose (PC1 = 44.5%) and cultivar (PC2 = 42.7%), showing RR’s stronger connection of RR to biomass and antioxidant accumulation under moderate Se. Overall, a single foliar application of 5 µM sodium selenate appears optimal to achieve effective Se enrichment while maintaining productivity and quality. These findings support basil as a promising candidate for Se biofortification in TCEA systems, with potential contributions to dietary Se intake. Full article

Zinc (Zn) deficiency affects over 30% of the global population, with the highest burdens in developing countries reliant on cereal-based diets. As a major dietary staple in regions such as Sub-Saharan Africa and Latin America, common bean (Phaseolus vulgaris L.) represents a promising vehicle for addressing hidden hunger. This review critically evaluates the efficacy of various strategies to enhance Zn concentration in common bean, ranging from agronomic to genetic manipulation, and proposes promising strategies for biofortifying common bean in developing countries that are resource- and technology-limited. Biofortification strategies include agronomic practices, conventional breeding, and genetic engineering, each with distinct strengths and limitations. Agronomic methods such as soil and foliar fertilization can rapidly increase micronutrient content, but they require recurrent costs and may not be sustainable for smallholders without subsidies. Genetic engineering, particularly transgenic approaches, can significantly boost Zn levels; however, regulatory hurdles, cost of production, and public acceptance remain significant obstacles to widespread adoption. Conventional breeding is secure and widely adopted, but is time-consuming and limited by genetic diversity, making it less precise and slower than genetic engineering. We argue for a context-specific and integrated biofortification framework that prioritizes agronomic interventions such as biofertilizer, seed priming, soil Zn application, and foliar Zn application as approaches for quick results. Moderate- to long-term progress towards a biofortified common bean can be achieved using conventional breeding methods by selecting for local germplasm that accumulates higher Zn amounts in grain. On the other hand, genetic engineering is best for rapid, targeted nutrient enhancement where genetic diversity is lacking, but faces regulatory and acceptance challenges. We recommend that policymakers prioritize frameworks that harmonize these approaches, improve communication and education regarding the benefits of biofortified crop produce, subsidize and strengthen biofortified seed systems, and promote soil health initiatives. Full article

Agronomic biofortification strategies have been used to increase selenium (Se) concentrations in edible parts, with broccoli cultivation showing high potential. Recent studies have demonstrated that prior application of selected elements during the seedling phase (priming) can enhance agronomic biofortification when this element is applied during the adult phase; however, no such effect has yet been reported for Se. Additionally, Se concentration in broccoli florets may be affected by post-harvest processing, thus determining losses is essential in the agronomic biofortification process. This study aimed to determine whether seedling production with priming using selenium (Se) could enhance different agronomic biofortification strategies for Se, and to evaluate the effect of post-processing on the Se concentration in broccoli. Seedlings were produced with and without priming (75 mg L⁻¹ of Se), and different application methods (soil and foliar), sources, and doses of Se were tested on Se concentration in broccoli florets. Foliar application strategies for Se were more effective than soil application for producing Se-biofortified broccoli. Seedlings produced and subjected to Se application to promote the priming effect enhanced Se absorption and increased Se concentration in broccoli florets. However, the highest Se absorption with a dry mass concentration exceeding 18 mg kg⁻¹ reduced broccoli production, except for Se applied via multi-nutrient fertilizer. Foliar fertilization strategies using 50 g of Se ha⁻¹ via multi-nutrient fertilizer, Se + organic compounds, and sodium selenate, along with the use of seedlings produced with priming and the application of 50 g of Se ha⁻¹ via multi-nutrient fertilizer using seedlings produced without priming, can provide Se amounts reaching the human dietary requirement of 60–70 µg day⁻¹, based on the adequate daily consumption of broccoli (40 g of broccoli). Different processing stages do not cause significant losses of Se in biofortified florets. Therefore, it is concluded that seedlings produced with priming combined with foliar Se applications are effective strategies for promoting agronomic biofortification of Se in broccoli florets for the human diet. Full article

Potato (Solanum tuberosum L.) is an important global food crop, being greatly valued for its high carbohydrate content and nutritional profile. In response to the world population’s rapid growth and the increasing need for nutritionally enhanced food quality, potato biofortification has become a key focus of agronomic research. This study investigated the effect of calcium (Ca) biofortification on two potato cultivars (Picasso and Rossi) cultivated in Portugal, assessing its impact on the photosynthetic functioning and the Ca content and distribution of tubers. At the beginning of the tuberization stage, seven foliar applications of CaCl₂ or Ca-EDTA at 12 kg ha⁻¹ were performed. The application of Ca-EDTA led to an increased Ca content in peeled tubers of Picasso (37%) and Rossi (16%), and 88% and 79% in unpeeled tubers, in the same cv. order and as compared to their controls, with Ca predominantly accumulating in the epidermis/peel region. Photosynthetic performance was negatively impacted by the Ca-EDTA treatment in Picasso but not in Rossi, which was reflected in the significant declines in net photosynthesis (P_n) and maximal (F_v/F_m) and actual (F_v′/F_m) photochemical efficiency of photosystem II. Additionally, both genotypes showed negative impacts (greater in Picasso) on the quantum yield of non-cyclic electron transport (Y_(II)) and photochemical quenching (q_L) after five foliar applications. This contrasted with the absence of negative impacts under the use of CaCl₂, which resulted in 17.1% (Picasso) and 29.5% (RFossi) increase in Ca content in peeled tubers, without any significant differences between the unpeeled tubers of both cvs. Moreover, only with CaCl₂, the tuber weight and yield were not negatively impacted. These findings pointed out that, although with a lower Ca increase in the tubers, CaCl₂ was the best suitable option for the Ca biofortification of these cvs. at the applied doses. Full article

Nutrient intake is vital for human health, yet micronutrient deficiencies remain widespread despite sufficient calorie consumption. Biofortification is the process by which the nutrient density of food crops is increased through various strategies without altering key agronomic characteristics. This approach is widely recognised as a cost-effective method for addressing micronutrient malnutrition. When combined with the nutritional properties and inherent resilience of underutilised crops to harsh conditions, biofortification emerges as highly promising and sustainable solution. This study investigates the effects of selenium biofortification by adding different doses of SeO₂ (0, 1, 2, and 4 μM) in the nutrient solution in three underutilised leafy vegetables [Portulaca oleracea L. (purslane), Taraxacum officinale L. (dandelion), and Mesembryanthemum crystallinum L. (iceplant)] grown in an open soilless system. The addition of SeO₂ to the nutrient solution increased yield in all three species, although iceplant exhibited reduced yield at the highest SeO₂ dose. In particular, the total yield of purslane was enhanced by 14–19% when treated with 1, 2, and 4 doses of SeO₂, whilst the dandelion yield increased by 25% under 4 μM SeO₂. Furthermore, the yield of iceplant increased by 14.7–17.8% at 1 and 2 μM SeO₂. SeO₂ application led to a dose-dependent increase in selenium concentration in the shoot tissues while remaining within safe intake limits. More specifically, selenium concentration in purslane, dandelion, and iceplant tissues increased by 92%, 91%, and 89%, respectively, at the highest SeO₂ dose (4 μΜ) compared to untreated plants. Selenium treatment also influenced the nutritional profile of the examined plant species. With regard to the antioxidant activity, the highest recorded value was observed at 1 μM SeO₂ for purslane and iceplant, and at 4 μM SeO₂ for dandelion. These values were enhanced by 20%, 12%, and 27%, respectively, in comparison with 0 μM SeO₂. In conclusion, rootzone SeO₂ supplementation via a nutrient solution can be considered an effective biofortification strategy that enhances growth characteristics and antioxidant properties of the three investigated underutilised leafy vegetables without compromising their nutritional value. Full article

This study investigated the effects of four selenium fertilizers (nano-Se, EDTA-chelated Se, organic Se, and microbial Se) at three concentrations (50, 25, and 12.5 mg·L⁻¹) on garlic (Allium sativum L. cv. ‘Xusuan 918’) through foliar application during critical growth stages. Comprehensive evaluation combining agronomic traits, yield components, nutritional quality (soluble sugars, vitamin C), and selenium accumulation revealed distinct fertilizer-specific responses. Organic Se at 50 mg·L⁻¹ (O1) maximized vegetative growth (21.83% increased plant spread), while 25 mg·L⁻¹ microbial Se (M2) showed optimal yield enhancement (10.04% higher bulb dry weight vs. CK). Notably, 50 mg·L⁻¹ nano-Se (N1) achieved simultaneous improvement in nutritional quality and selenium biofortification (29-fold bulb Se enrichment). Principal component analysis integrated with membership function method identified N1 treatment (D-value = 0.571) as the most effective protocol for selenium-enriched garlic production, demonstrating the importance of fertilizer selection for crop-specific selenium management strategies. Full article

Enhancing the nutritional content of crops is crucial for safeguarding human health and mitigating global hunger. A viable method for attaining this goal is the planned implementation of various agronomic practices, including tillage and nutrient provision. A field experiment was executed at the Hungarian University of Agriculture and Life Sciences in Gödöllő in the 2023 and 2024 growing seasons. The study aimed to assess the effects of foliar nutrient supply and soil tillage methods on the grain nutritional composition and mineral content of winter barley. Employing a split-plot design with three replications, the experiment included four nutrient treatments (control, bio-cereal, bio-algae, and MgSMnZn blend) and two soil tillage types (i.e., plowing and cultivator). The results indicated that while protein content was not influenced by the main effects of nutrients and tillage, the levels of β-glucan, starch, crude ash, and moisture content were significantly (p < 0.05) affected by the nutrient treatments and by growing year, treated as a random factor. Notably, bio-algae and bio-cereal nutrients, combined with cultivator tillage, enhanced β-glucan content. All applied nutrient treatments increased the level of starch compared to the control. With regard to grain mineral content, the iron and zinc content responded to the nutrient supply, tillage, and growing year. However, applying a multiple-nutrient composition-based treatment did not increase iron and zinc levels, suggesting that individual applications may be more effective for increasing the content of these minerals in grains. Cultivator tillage improved iron and zinc levels. Moreover, manganese (Mn) and copper (Cu) were predominantly affected by nutrient availability and by growing seasons as a random factor. Therefore, to improve grain quality, this study emphasizes the significance of proper nutrient and tillage methods by focusing on the intricate relationships between agronomic techniques and environmental factors that shape barley’s nutritional profile. Full article

Microelement deficiencies, often termed “hidden hunger”, represent a significant global health challenge. Optimal human health relies on adequate dietary intake of essential microelements, including selenium (Se), zinc (Zn), copper (Cu), boron (B), manganese (Mn), molybdenum (Mo), iron (Fe), nickel (Ni), and chlorine (Cl). In recent years, there has been a growing focus on vitality and longevity, which are closely associated with the sufficient intake of essential microelements. This review focuses on these nine elements, whose bioavailability in the food chain is critically determined by their geochemical behavior in soils. There is a necessity for an understanding of the sources, soil–plant transfer, and plant uptake mechanisms of these microelements, with particular emphasis on the influence of key soil properties, including pH, redox potential, organic matter content, and mineral composition. There is a dual challenge of microelement deficiencies in agricultural soils, leading to inadequate crop accumulation, and the potential for localized toxicities arising from anthropogenic inputs or geogenic enrichment. A promising solution to microelement deficiencies in crops is biofortification, which enhances nutrient content in food by improving soil and plant uptake. This strategy includes agronomic methods (e.g., fertilization, soil amendments) and genetic approaches (e.g., marker-assisted selection, genetic engineering) to boost microelement density in edible tissues. Moreover, emphasizing the need for advanced predictive modeling techniques, such as ensemble learning-based digital soil mapping, enhances regional soil microelement management. Integrating machine learning with digital covariates improves spatial prediction accuracy, optimizes soil fertility management, and supports sustainable agriculture. Given the rising global population and the consequent pressures on agricultural production, a comprehensive understanding of microelement dynamics in the soil–plant system is essential for developing sustainable strategies to mitigate deficiencies and ensure food and nutritional security. This review specifically focuses on the bioavailability of these nine essential microelements (Se, Zn, Cu, B, Mn, Mo, Fe, Ni, and Cl), examining the soil–plant transfer mechanisms and their ultimate implications for human health within the soil–plant–human system. The selection of these nine microelements for this review is based on their recognized dual importance: they are not only essential for various plant metabolic functions, but also play a critical role in human nutrition, with widespread deficiencies reported globally in diverse populations and agricultural systems. While other elements, such as cobalt (Co) and iodine (I), are vital for health, Co is primarily required by nitrogen-fixing microorganisms rather than directly by all plants, and the main pathway for iodine intake is often marine-based rather than soil-to-crop. Full article