Search Results (4)

Iron (Fe) and Zinc (Zn) deficiencies in crops pose indirect problems for human health. The risk of these deficiencies increases with high doses of phosphate fertilizers. Fertilizers obtained through recycling—so-called bio-based fertilizers (BBFs)—can contain significant amounts of Fe and Zn, which can contribute to crop biofortification. Although the use of some organic BBFs has been shown to improve biofortification, an in-depth study on this effect and on the effect of P on Fe and Zn nutrition with the use of different kinds of bio-based P fertilizers is still lacking. A pot experiment with 11 different BBFs was conducted using two soils with different physicochemical properties that affect P, Fe, and Zn dynamics (one rich in CaCO₃ and the other rich in Fe oxides) to assess their biofortification effects on wheat and sunflower. Although some BBFs increased Fe concentration in the edible parts, the overall trend was towards an increased P:Fe ratio (up to 62%), which decreased Fe digestibility. On the other hand, all BBFs led to Zn biofortification, with a 27% decrease in the P:Zn ratio in the CaCO₃-rich soil, while in the Fe oxide-rich soil, the decrease was up to 61%. The supply of Zn and organic C, as well as the dominant P forms in BBFs, were the main factors explaining Zn biofortification. Bio-based fertilizers also decreased the antagonism between P and Zn and between Fe and Zn. The results demonstrated that the inclusion of BBFs in agrosystems management can contribute to improving the quality of human diets, at least with regard to Zn intake, while also contributing to more sustainable fertilization practices. Full article

Elevated levels of cadmium (Cd) and lead (Pb) in the edible parts of rice (Oryza sativa L.) grown in agricultural soils may enter the human body through the food chain, posing significant health risks. In this study, rice and paired rhizosphere soil samples were collected from 194 locations in Jiangsu Province, China, with 60 samples selected for diffusive gradients in thin films (DGT) extraction analysis. The findings indicate that total soil concentrations of Cd and Pb are inadequate for assessing cadmium bioavailability, implying that current soil quality standards may not accurately reflect the bioaccessible fractions of these metals. Both DGT and soil solution measurements effectively predicted crop Cd levels, with the effective concentration (C_E) derived from the DGT-induced soil flux (DIFS) model showing the strongest correlation with rice Cd content. Pearson correlation analysis and a random forest (RF) model further identified critical factors influencing rice uptake of Cd and Pb, including soil iron (Fe) content, cation exchange capacity (CEC), pH, and the levels of zinc (Zn) and selenium (Se), which antagonize Cd uptake. Full article

Fusarium Wilt Tropical Race 4 (TR4) is spreading rapidly all over the world and threatens banana production, especially the Cavendish variety, which is the main commercial cultivar in Asia. This work aims to use beneficial microbes and fertilizers to control TR4. Both Bacillus mycoides NP02 (BM) and Bacillus amyloliquefaciens BaPD1 (BA) antagonized TR4 growth in plate tests. In addition, basal nutrients (BN) in combination with BM and BA were used to treat 1-month-old banana seedlings infected by Fusarium Wilt; plant growth and nutrients of leaves were investigated after 6-month cultivation in the field. The seedling survival rates for uninfected and infected controls without the microbes were 89.4 ± 14.8% and 50 ± 10.7%, respectively. In contrast, the corresponding rates for 2BM, 5BM, 1BA, F1 (5BM + 4BN + 1BA) and G1 (1BM + 4BN + 1BA) in the infected plants were 80 ± 9.4%, 83 ± 4.3%, 85 ± 14.2%, 96.7 ± 1.9% and 96.7 ± 3.3%, respectively. The 2BM treatment promoted the growth of both uninfected and infected banana plants and the 5BA treatment significantly reduced the severity index by 1.45-fold. Plants infected with TR4 showed significantly reduced contents of nitrogen and potassium, but the contents of iron, copper and zinc were higher than those of healthy plants. Additionally, 1BM treatment stimulated the accumulation of nitrogen and zinc ions in the leaves of uninfected plants. Both the 1BA and 2BN treatments increased the iron (Fe) and nickel (Ni) metal ion levels of TR4 infected plants. The F2 (5BM + 2BN + 1BA) treatment significantly maintained the growth of banana plants under TR4 stress with increased contents of nickel and zinc in banana leaves, suggesting that these ions may play a key role in stimulating the growth of banana plants under the threat of TR4. This work shows the potential of applying BM, BN and BA in the control of Fusarium wilt in field conditions. Full article

The recognized antagonistic actions between zinc and iron prompted us to study this subject in children. A convenience sample was used. Thirty healthy children between 8 and 9 years of age were studied with the aim of establishing the effect of a 3-mo oral zinc supplementation on iron status. Fifteen individuals were given a placebo (control group), and 15 were given 10 mg Zn/day (experimental group). Blood samples were collected at 0, 60, 120, 180 and 210 min after a 12-h overnight fast, before and after placebo or zinc supplementation. This supplementation was associated with significant improvements in energy, protein, fat, carbohydrate, fiber, calcium, iron, and zinc intake in accordance with the recommendations for age and sex. The basal serum zinc concentration significantly increased after oral zinc supplementation (p < 0.001). However, basal serum iron concentrations and area under the iron curves significantly decreased in the experimental group (p < 0.0001) and remained at the same level throughout the 210-min study. The values obtained for hemoglobin, mean corpuscular volume, ferritin, transferrin, transferrin saturation, ceruloplasmin and total protein were within normal reference ranges. In conclusion, the decrease in serum iron was likely due to the effects of chronic zinc administration, and the decrease in serum iron was not sufficient to cause anemia. Full article