Does the application of silicon and Moringa seed extract reduce heavy metals toxicity in potato tubers treated with phosphate fertilizers?

Environmental Science and Pollution Research - Two field trials were carried out in two successive agricultural seasons to study the possibility of using silicon (Si) and Moringa seed extract (MSE)...     

The nitrogen and phosphorus footprints of food products in Yemen over the last 57 years

Food nitrogen (N) and phosphorus (P) footprints are indicators for determining the losses of N and P over food production (FP) and food consumption (FC) chain. Yemen is an interesting case because, given the country’s heavy dependence on food imports, food insecurity, and poverty, the N footprint (NF) and P footprint (PF) could affect its future development. However, NF and PF over time have not yet been studied in Yemen. Therefore, this is the first paper to compute the NF and PF in Arabian Peninsula (a case study from Yemen) by an adjusted model of N-Calculator, by computing virtual N (VNFs) and virtual P (VPFs) factors for main foodstuffs. The NF (kg N cap^?1 year^?1) and PF (kg P cap^?1 year^?1) elevated from 5.56 and 1.20 in the 1960s to 15.2 and 4.79 during 2011–2017, respectively, while the national NF (Gg [10⁹ g] N year^?1) and national PF (Gg P year^?1) increased from 27.7 and 6.77 in the 1960s to 358 and 122 during 2011–2017, respectively. Cereal was the largest contributor to the NF and PF in Yemen over the past 57 years. FP contributes approximately 80% and 86% of the total NF and PF during 2011–2017. Therefore, if possible, the best way for consumers and farmers in Yemen to decrease NF and PF is to focus efforts on increasing FP and FC of foodstuffs with less VNFs and VPFs. The consumption of vegetable-fruit, legumes, starchy, eggs, poultry, and fish should be increased as their NF and PF are low. However, people in Yemen suffer from shortage of resources and lack of awareness, and thus they do not have the opportunity to choose foodstuffs that are low in NF and PF. Accordingly, policymakers should encourage integrated approaches that introduce powerful tools for controlling crop and livestock production in conjunction with enhancements in nutrient use efficiency.

     

Biological silicon nanoparticles improve Phaseolus vulgaris L. yield and minimize its contaminant contents on a heavy metals-contaminated saline soil

The synthesis of biological silicon nano-particles (Bio-Si-NPs) is an eco-friendly and low-cost method. There is no study focusing on the effect of Bio-Si-NPs on the plants grown on saline soil contaminated with heavy metals. In this study, an attempt was made to synthesis Bio-Si-NPs using potassium silica florid substrate, and the identified Aspergillus tubingensis AM11 isolate that separated from distribution systems of the potable water. A two-year field trial was conducted to compare the protective effects of Bio-Si-NPs (2.5 and 5.0 mmol/L) and potassium silicate (10 mmol/L) as a foliar spray on the antioxidant defense system, physio-biochemical components, and the contaminants contents of Phaseolus vulgaris L. grown on saline soil contaminated with heavy metals. Our findings showed that all treatments of Bio-Si-NPs and potassium silicate significantly improved plant growth and production, chlorophylls, carotenoids, transpiration rate, net photosynthetic rate, stomatal conductance, membrane stability index, relative water content, free proline, total soluble sugars, N, P, K, Ca²⁺, K⁺/Na⁺, and the activities of peroxidase, catalase, ascorbic peroxidase and superoxide oxide dismutase. Application of Bio-Si-NPs and potassium silicate significantly decreased electrolyte leakage, malondialdehyde, H₂O₂, O₂^??, Na⁺, Pb, Cd, and Ni in leaves and pods of Phaseolus vulgaris L. compared to control. Bio-Si-NPs were more effective compared to potassium silicate. Application of Bio-Si-NPs at the rate of 5 mmol/L was the recommended treatment to enhance the performance and reduce heavy metals content on plants grown on contaminated saline soils.