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The UK dietary reference value framework. (a) Estimated average requirement (EAR), reference nutrient intake (RNI), and lower RNI (LRNI), based on a hypothetical population with an EAR for a nutrient of 100 arbitrary units and an SD of 20. Data are expressed as a probability density distribution (---) and as a cumulative probability function (–––). (b) Illustrative nutrient intake among a population whose mean intake equals the RNI (SD = 20) and which is normally distributed. The probability density distribution is the grey-shaded area; the cumulative probability function () shows that the risk of intake deficiency is extremely low. Adapted from Department of Health (1) .
Source publication
Human individuals require at least 20 inorganic elements ('minerals') for normal functioning. However, much of the world's population is probably deficient in one or more essential minerals and at increased risk of physiological disorders. Addressing these 'hidden hungers' is a challenge for the nutrition and agriculture sectors. Mineral deficienci...
Contexts in source publication
Context 1
... and planned at a population level using the dietary reference value (DRV) framework. The DRV framework was intro- duced in 1991 by the Department of Health to replace the previous system of RDA (1) . The DRV framework includes an estimated average requirement (EAR), a reference nutrient intake (RNI) and a lower RNI (LRNI) for each mineral ( Fig. 1(a)). Half of the group will usually require more of a mineral than the EAR intake level, and half will require less (1) . The RNI and LRNI are defined as the intakes of two standard deviations (SD) above and below the EAR, respectively ( Fig. 1(a)). The RNI defines an intake that is sufficient, or more than sufficient, for about 97% of a ...
Context 2
... average requirement (EAR), a reference nutrient intake (RNI) and a lower RNI (LRNI) for each mineral ( Fig. 1(a)). Half of the group will usually require more of a mineral than the EAR intake level, and half will require less (1) . The RNI and LRNI are defined as the intakes of two standard deviations (SD) above and below the EAR, respectively ( Fig. 1(a)). The RNI defines an intake that is sufficient, or more than sufficient, for about 97% of a population. If the average mineral intake of a group approximates the RNI, mineral deficiency risk within that group is considered small (e.g. Fig. 1(b)). The LRNI defines an intake that is sufficient only for those few people in the group who ...
Context 3
... LRNI are defined as the intakes of two standard deviations (SD) above and below the EAR, respectively ( Fig. 1(a)). The RNI defines an intake that is sufficient, or more than sufficient, for about 97% of a population. If the average mineral intake of a group approximates the RNI, mineral deficiency risk within that group is considered small (e.g. Fig. 1(b)). The LRNI defines an intake that is sufficient only for those few people in the group who have low needs, and therefore intakes below the LRNI carry a very high risk of defi- ciency (1) . For UK adults in the age range 19-64 years, the RNI/EAR/LRNI for Ca is 700/525/400 mg/d, and for Mg is 270/200/150 (for females) and 300/250/190 ...
Citations
... which clearly shows that the "short planks" in the crop nutrient barrel theory of China are changing from N, P, and K to Mg (Chen et al. 2022). Therefore, Mg fertilizer application is required to improve both crop yield and nutritional value, in order to ensure food security and human health (Broadley and White 2010;Cakmak 2015;Kisters and Gröber 2013). ...
Purpose
The application of magnesium (Mg) fertilizer to alleviate Mg deficiency and improve crop yield has gained wide recognition. However, high Mg leaching loss is a growing concern in high rainfall areas, especially in acidic soils. Developing Mg fertilizer with less risk of leaching and adequate Mg supply to crops in a convenient way is worth considering in agricultural production.
Methods
In this study, five Mg-fortified mono-ammonium phosphate (MAP) fertilizers were produced with anhydrous magnesium sulfate (MgSO4) and dolomite (CaMg(CO3)2) in various ratios. Nutrient solubility, Mg nutrient release, Mg leaching, and agronomic effectiveness under rainfall conditions in an acidic soil were evaluated.
Results
Addition of the Mg sources to the MAP fertilizer did not affect P solubility of the fertilizer. The MAP fertilizers fortified with both MgSO4 and dolomite showed an initially fast release of Mg followed by slower release. In a pot experiment with simulated rainfall, the amount of Mg leached significantly decreased with increasing proportion of dolomite in the Mg-fortified fertilizers, which varied from 19.1% for the MgSO4 treatment to 3.8% for the dolomite treatment. Shoot dry matter yield and Mg concentration of soybean were higher for treatments with Mg-fortified MAP than for MAP-only.
Conclusions
The use of dual-release Mg sources in macronutrient fertilizers could be a promising strategy to better meet crop Mg demands and effectively reduce Mg leaching losses, especially in sandy soils of high rainfall areas.
... Vegetable growers tend to apply large amounts of fertilizers, causing the accumulation of excessive salts (e.g., Mg 2+ , Ca 2+ , and Na + ) in the soil [26]. The massive accumulation of salts would lead to elemental antagonism and thereby strongly inhibit the plant's absorption of other nutrients [8,27]. It has been reported that increasing the supplied concentration of Mg 2+ ions can reduce the relative quantity of Mg 2+ ions adsorbed by xylem conduit walls and improve ion transport efficiency to the shoots. ...
Magnesium (Mg) plays a crucial role in crop growth, but how Mg supply level affects root growth and nutrient absorption in vegetable crops with different genotypes has not been sufficiently investigated. In this study, the responses of tomato (Solanum lycopersicum L.) and cucumber (Cucumis sativus L.) crops to different levels of Mg supply were explored. Four levels of Mg treatment (i.e., 0.2, 1.0, 2.0, 3.0 mmol/L) were applied under hydroponic conditions, denoted as Mg0.2, Mg1, Mg2, and Mg3, respectively. The results showed that with increasing Mg levels, the plant biomass, root growth, and nutrient accumulation in both vegetable crops all increased until reaching their maximum values under the Mg2 treatment and then decreased. The total biomass per tomato plant of Mg2 treatment was 30.9%, 14.0%, and 14.0% higher than that of Mg0.2, Mg1, and Mg3 treatments, respectively, and greater increases were observed in cucumber plant biomass (by 54.3%, 17.4%, and 19.9%, respectively). Compared with the Mg0.2 treatment, the potassium (K) and calcium (Ca) contents in various plant parts of both crops remarkably decreased under the Mg3 treatment. This change was accompanied by prominently increased Mg contents in various plant parts and para-hydroxybenzoic acid and oxalic acid contents in root exudates. Irrespective of Mg level, plant biomass, root growth, nutrient accumulation, and root exudation of organic acids were all higher in tomato plants than in cucumber plants. Our findings indicate that excessive Mg supply promotes the roots to exude phenolic acids and hinders the plants from absorbing K and Ca in different genotypes of vegetable crops despite no effect on Mg absorption. A nutritional deficiency of Mg stimulates root exudation of organic acids and increases the types of exuded organic acids, which could facilitate plant adaption to Mg stress. In terms of root growth and nutrient absorption, tomato plants outperform cucumber plants under low and medium Mg levels, but the latter crop is more tolerant to Mg excess.
... It is essential for the normal functioning of cells and organs [7,8] due to its involvement in nerve transmission, muscle contractions, blood pressure regulation, and skeleton integrity [5,[9][10][11]. Fruits, legumes, starchy roots and tubers, whole grains, and vegetables are the primary dietary sources of potassium [6,12,13]. The regulation of urinary potassium excretion is primarily responsible for the homeostatic control of serum potassium concentration. ...
Background:
Hypertension (HT) and obesity have both been on the rise in children. Each is associated with an increase in cardiovascular disease risk, and both track into adulthood.
Objectives:
This study aimed to identify the association of sodium intake (Na), potassium (K) intake, and sodium-to-potassium (Na/K) ratio with the development of HT and abdominal obesity amongst the Ellisras rural population over time.
Methods:
In this longitudinal study, data on dietary intake of Na and K were collected using a 24 h recall questionnaire from a total of 325 participants tracked from 1999 (5-12 years), 2001 (7-14 years), and 2015 (18-30 years). The averages of Na and K intake were analysed using local food tables and the South African Food Composition Database System (SAFOODS). In addition, blood pressure (BP) and anthropometric measurements (waist circumference (WC) and height) were also examined. Parametric (independent t-test) and Chi-square/Fishers exact tests were conducted to determine the difference between the years for numerical data and categorical variables. A generalised estimating equation (GEE) was used to assess the association of Na intake, K intake and their ratio on BP, WC, and waist-to-height ratio (WHtR).
Results:
Our results indicate a significant positive association between K intake and WHtR, and even though the model was adjusted for age and sex, there was still an association with WHtR. The Na/K ratio was associated with both BP measurements and abdominal obesity, respectively. Furthermore, Na/K was shown to be associated with an increased risk of developing HT and abdominal obesity.
Conclusions:
In our study, we observed that an increase in the Na/K ratio is a predictor of HT and abdominal obesity over time compared to Na and K alone. However, more studies are required to further prove this.
... 13 Depending on the context, additional analysis should also test the potential contribution of fortifying other, more broadly consumed and accessible foods, such as maize or rice, with calcium, or increasing the calcium content of common staple foods using biofortification. 22,65,66 Water is universally consumed, and as such, the calcium content of water could impact the diets of most populations. 22 However, water intake is rarely captured in dietary surveys; for this reason, this analysis tested different daily water portions. ...
Adequate calcium intake is essential for health, especially for infants, children, adolescents, and women, yet is difficult to achieve with local foods in many low‐ and middle‐income countries. Previous analysis found it was not always possible to identify food‐based recommendations (FBRs) that reached the calcium population recommended intake (PRI) for these groups in Bangladesh, Guatemala, and Uganda. We have modeled the potential contribution of calcium‐fortified drinking water or wheat flour to FBR sets, to fill the remaining intake gaps. Optimized diets containing fortified products, with calcium‐rich local foods, achieved the calcium PRI for all target groups. Combining fortified water or flour with FBRs met dietary intake targets for adolescent girls in all geographies and allowed a reduction from 3–4 to the more feasible 1–2 FBRs. Water with a calcium concentration of 100 mg/L with FBRs was sufficient to meet calcium targets in Uganda, but higher concentrations (400–500 mg/L) were mostly required in Guatemala and Bangladesh. Combining calcium‐fortified wheat flour at 400 mg/100 g of flour and the FBR for small fish resulted in diets meeting the calcium PRI in Bangladesh. Calcium‐fortified water or flour could improve calcium intake for vulnerable populations, especially when combined with FBRs based on locally available foods.
... The accumulation, transport, and distribution of nutrients in plants are also important processes in nutrient utilisation. In an individual plant, the ionome is specific to organ type; for example, calcium (Ca) concentrations in leaves are higher than those in tubers as a result of its limited phloem mobility (Broadley and White 2010). Nutrients like Ca, potassium (K), and magnesium (Mg) accumulate to a different extent in different organs in Malus domestica, Pyrus pyrifolia, and Glycine max (Shibuya et al. 2015). ...
Knowledge of the ionome of plant organs helps us understand a plant's nutritional status. However, the ionome of Macadamia (Proteaceae), which is an important nut-producing tree, remains unknown. We aimed to characterise the allocation of biomass and nutrient-partitioning patterns in three macadamia genotypes. We excavated 15 productive trees (three cultivars at 21years of age; two cultivars at 16years of age) in an orchard. Biomass, nutrient concentrations, and contents of roots, stems, branches, and leaves were analysed. Dry weight of roots, stems, branches and leaves accounted for 14-20%, 19-30%, 36-52%, and 12-18% of total plant weight, respectively. No significant difference was found in the total biomass among the cultivars at the same age. Compared with most crop plants, macadamia had low phosphorus (P) concentrations in all organs (<1gkg-1), and low leaf zinc (Zn) concentration (8mgkg-1). In contrast, macadamia accumulated large amounts of manganese (Mn), with a 20-fold higher leaf Mn concentration than what is considered sufficient for crop plants. Leaves exhibited the highest nutrient concentrations, except for iron and Zn, which exhibited the highest concentrations in roots. The organ-specific ionomics of Macadamia is characterised by low P and high Mn concentrations, associated with adaptation to P-impoverished habitats.
... Moreover, given that the Na toxicity is dependent on the K/Na ratio in the cell, and its capacity to compartmentalize this ion in the vacuole and not on its absolute amount in the cytosol, the unaffected K concentration of the leaf tissues of the LNa and HNa treatments could have played a role in alleviating the NaCl salinity stress [130]. Given that Ca is an important nutrient for plant growth and signal under various stress conditions [131][132][133][134][135][136], it is not expected to be treated as a stress factor by the plants and, as a result, it is not considered to be responsible for the acute reduction of the LFW of the CaCl 2 treatments. Nevertheless, the greater yield reduction was observed in the LCa and HCa treatments. ...
Corn salad (Valerianella locusta) is a popular winter salad, cultivated as an ingredient for ready-to-eat salads. The application of mild salinity stress (eustress) can increase the flavor and reduce the nitrate content of certain crops but, at the same time, a wrong choice of the eustress type and dose can negatively affect the overall productivity. In this research, the effects of different isosmotic salt solutions, corresponding to two different electrical conductivity (EC) levels, were investigated on the yield and mineral composition of hydroponically grown Valerianella locusta “Elixir”. Five nutrient solutions (NS) were compared, including a basic NS used as the control, and four saline NS were obtained by adding to the basic NS either NaCl or CaCl2 at two rates each, corresponding to two isosmotic salt levels at a low and high EC level. Corn salad proved moderately susceptible to long-term salinity stress, suffering growth losses at both low and high EC levels of saline solution, except from the low NaCl treatment. Hence, it appears that mild salinity stress induced by NaCl could be employed as an eustress solution and corn salad could be cultivated with low-quality irrigation water (20 mM NaCl) in hydroponic systems.
... Similarly, when liquid fertilizers are applied to the soil, Mg 2+ and Ca 2+ may combine with CO 3 2− in the soil to form precipitates, thus affecting their uptake and utilization by plants and reducing their biological effectiveness (Broadley and White, 2010), therefore, attention should be paid to soil characteristics when applying liquid fertilizers. It is important to note that the risk of soil erosion may lead to an increase in water hardness due to ions entering the water body, therefore, the evaluation of the ecological risk indicator for liquid fertilizers Mg 2+ and Ca 2+ can be analogous to the hardness indicator for water, which in engineering practice is defined as the sum of Mg 2+ and Ca 2+ concentrations (Tang et al., 2021). ...
The recovery of nutrients from livestock manure has generated a lot of interest in biosolids value-adding. There is now more research on manure with high solids content but less study on manure with lower solids content. This study used swine manure slurry as the research object and comprehensively examined the characteristics of organic matter conversion, nitrogen, phosphorus, and metals release during the catalytic-thermal hydrolysis (TH) process. It was found that ammonia nitrogen showed a continuous increase with increasing temperature while inorganic phosphorus showed a rising and then decreasing trend. The addition of HCl and H2O2 (TH-HCl-H2O2) promoted the hydrolysis of organic matter, showing the best nitrogen and phosphorus release performance, releasing 62.2% of inorganic phosphorus and 50.8% of nitrogen. The release characteristics of nutrients and metals from the TH process were significantly affected by the addition of HCl and H2O2, according to structural equation modelling study. The data analysis demonstrated that the liquid fertilizer produced by TH did not surpass the environmental risk associated with nutrients or the ecological risk associated with heavy metals. This study would offer theoretical justification for biowaste conversion for agricultural applications.
... There has been a growing interest in mineral efficiency in crops since at least 40% of the world's arable land suffers from mineral deficiencies [2] which usually demand the use of inorganic fertilizers in order to sustain high yields. In addition, it has been suggested from dietary surveys that an approximate 10% of the energetically well-nourished adult population in developed countries assumes a suboptimal intake of macronutrients such as K, Ca and Mg and is considered to be at risk of deficiency [3]. Meanwhile, the significant increase in the fertilizers' cost and growing concerns regarding the environmental impact of the recently excessive fertilizer inputs, coupled with the increasing demand for fresh and nutritious food on an overpopulated planet, further enhances the importance of both nutrient-efficient cultivars and agricultural systems [4,5]. ...
Nutrient-efficient plants and agricultural systems could tackle issues resulting from conventional agriculture. Spiny chicory (Cichorium spinosum L.), a very adaptive, wild edible vegetable, is gaining commercial interest as a functional food. Floating-raft hydroponics is a method commonly used for the commercial cultivation of leafy vegetables due to numerous advantages compared to soil cultivation. In this paper, the simultaneous effects of different potassium, calcium and magnesium ratios and different electrical conductivity (EC) levels on the growth and mineral composition of hydroponically grown C. spinosum were investigated. Four nutrient solutions (NS) were compared, two NS with low EC (L, 2.4 dS/m) and two with high EC (H, 3.6 dS/m) with K:Ca:Mg ratios of either 50:40:10 or 40:50:10. The results showed no interactions between the two factors. No significant effects were observed on the fresh and dry weight, leaf number and leaf area. High EC levels increased the K content and decreased the Mn and Zn content in the leaf tissues. The 40:50:10 ratio led to increased Ca content in plant tissues. The Nitrate-N was only affected by the EC level and was increased under H conditions, whereas the total-N was not affected.
... The Mg-related nutritional disorders in humans are linked to declining Mg concentrations in the soil and food crops (Rosanoff, 2013;Rosanoff and Kumssa, 2020). Therefore, optimizing Mg nutrition is an imperative concern for food security and human health (Broadley and White, 2010). ...
Magnesium (Mg) is an essential nutrient for a wide array of fundamental physiological and biochemical processes in plants. It largely involves chlorophyll synthesis, production, transportation, and utilization of photoassimilates, enzyme activation, and protein synthesis. As a multifaceted result of the introduction of high-yielding fertilizer-responsive cultivars, intensive cropping without replenishment of Mg, soil acidification, and exchangeable Mg (Ex-Mg) leaching, Mg has become a limiting nutrient for optimum crop production. However, little literature is available to better understand distinct responses of plants to Mg deficiency, the geographical distribution of soil Ex-Mg, and the degree of Mg deficiency. Here, we summarize the current state of knowledge of key plant responses to Mg availability and, as far as possible, highlight spatial Mg distribution and the magnitude of Mg deficiency in different cultivated regions of the world with a special focus on China. In particular, ~55% of arable lands in China are revealed Mg-deficient (< 120 mg kg⁻¹ soil Ex-Mg), and Mg deficiency literally becomes increasingly severe from northern (227–488 mg kg⁻¹) to southern (32–89 mg kg⁻¹) China. Mg deficiency primarily traced back to higher depletion of soil Ex-Mg by fruits, vegetables, sugarcane, tubers, tea, and tobacco cultivated in tropical and subtropical climate zones. Further, each unit decline in soil pH from neutral reduced ~2-fold soil Ex-Mg. This article underscores the physiological importance of Mg, potential risks associated with Mg deficiency, and accordingly, to optimize fertilization strategies for higher crop productivity and better quality.
... Tomato (Solanum lycopersicum L.) is one of the most important vegetable plants worldwide and it requires more Mg to form the same biomass than grass or grain crops (Broadley and White, 2010;Gerendás and Führs, 2013). In this study, we used tomato as a model plant to investigate the response of seedlings, especially the root system, to low external Mg supply at the molecular level. ...
Magnesium (Mg) deficiency is becoming a widespread limiting factor for crop production. How crops adapt to Mg limitation remains largely unclear at the molecular level. Using hydroponic-cultured tomato seedlings, we found that total Mg²⁺ content significantly decreased by ∼80% under Mg limitation while K⁺ and Ca²⁺ concentrations increased. Phylogenetic analysis suggested that Mg transporters (MRS2/MGTs) constitute a previously uncharacterized 3-clade tree in planta with two rounds of asymmetric duplications, providing evolutionary evidence for further molecular investigation. In adaptation to internal Mg deficiency, the expression of six representative MGTs (two in the shoot and four in the root) was up-regulated in Mg-deficient plants. Contradictory to the transcriptional elevation of most of MGTs, Mg limitation resulted in the ∼50% smaller root system. Auxin concentrations particularly decreased by ∼23% in the Mg-deficient root, despite the enhanced accumulation of gibberellin, cytokinin, and ABA. In accordance with such auxin reduction was overall transcriptional down-regulation of thirteen genes controlling auxin biosynthesis (TAR/YUCs), transport (LAXs, PINs), and signaling (IAAs, ARFs). Together, systemic down-tuning of gene expression in the auxin signaling pathway under Mg limitation preconditions a smaller tomato root system, expectedly stimulating MGT transcription for Mg uptake or translocation.
