Effects of Green Silver Nanoparticles on Soil Quality and Induced Germination: A Future Alternative Fertilizer or Environmental Toxicant? (original) (raw)
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Effects of green synthesized silver nanoparticles on soil properties
Journal of Medicinal Plants Studies, 2020
Silver nanoparticles (Ag NPs) were synthesized using culture filtrate of fungal antagonist Trichoderma asperellum for which silver nitrate was used as the precursor. The Ag NPs thus formed were then characterized by using UV-Vis spectrophotometer, Dynamic Light Scattering (DLS), Zetasizer, Transmission Electron Microscope (TEM) and Energy Dispersive X-Ray Analysis (EDX). The UV-Vis spectroscopy showed a characteristic Surface Absorption Band at 420 nm which confirmed the formation of silver nanoparticles. DLS and TEM study revealed the uniform and well-dispersed nature of the biosynthesized nanoparticles with a spherical shape. The average particle size recorded was 8.26 nm with polydispersity index of 0.857. The charge of silver nanoparticles determined by zeta sizer had a negative potential value of -1.34 mV which indicated stability on dispersion. EDX results showed biosynthesized material contained 32.18% silver, 10.16% oxygen, and 57.66% carbon. The silver nanoparticles were ap...
Silver nanoparticles stabilized by humic substances adversely affect wheat plants and soil
Journal of Nanoparticle Research, 2020
More than 50% of engineered nanomaterials released into the environment contain silver nanoparticles (Ag-NPs). The mobility, bioavailability, and toxicity of engineered Ag-NPs are known to depend on their properties and the environmental conditions. However, almost nothing is known about the fate of naturally occurring Ag-NPs, which are formed during the reduction of Ag + by natural organic matter, primarily humic substances (HSs). The aim of this work was to study the interaction of soils and plants with simulated natural Ag-NPs, i.e., Ag-NPs stabilized with HSs (Ag-HS-NPs). To reach this goal, Ag-HS-NPs were synthesized, and their sorptiondesorption behavior on two contrasting soils (a mineral soil and one rich in organic matter) was evaluated, including alterations in the mineral composition of the soil solution. In parallel, the influence of Ag-HS-NPs on wheat seedling growth was estimated. Introduction of Ag-HS-NPs into the soils resulted in a 1.3-to 2-fold or greater increase in the concentration of many elements in the soil solution (Al, Cr, Cu, Fe, etc.), and this effect was more pronounced for the organic soil than for the mineral soil. To explain this effect, we hypothesized that this phenomenon was due to the partial dissolution of Ag-HS-NPs leading to the production of Ag + that could be further reduced by soil organic matter, which was correspondingly oxidized. Therefore, the partial breaking of soil aggregates because of the decomposition of soil organic matter in the presence of Ag-HS-NPs could be expected. Plants treated with Ag-HS-NPs demonstrated a lower rate of water uptake, which decreased by over 81%. The shoot and root biomass decreased by 15-17% and by 13-15%, respectively. This study clearly demonstrates an underestimated hazard of Ag-NPs formed in nature in terms of their ability to adversely affect the environment.
Effect of silver nanoparticles on seed protection in different soils
2010
To investigate the possibility of using silver nanoparticles for protection of a living organism, wheat seeds were coated with these particles and planted. If germination of seeds is not affected by this new nano-treatment, the method can be used on a wide range of common treatment for seed protection. The effect of treatment on seeds with this particle protection against fungi was compared with seeds treated with a conventional preplanting fungicide (Carboxitiram). Being that soil is the most common medium for plant growth in agriculture, this can play a major role in plants life and their relationships with other factors in the field. This study looks at the effects of different soil conditions on pre-treatment. The effect on soils with different levels of nutrient, pH and humidity were investigated. Results showed that soil conditions have little affect on seed protection with silver nanoparticles against fungi, and protection is completely independent of soil conditions. Results...
Emerging Agriculture Applications of Silver Nanoparticles
ES Food & Agroforestry, 2021
Agriculture farming is the foundation of most developing economies, roughly 60% of the population relies on agriculture. Indian farming division represents 18% of India's total national output and gives work to 50% of the workforce of the nation. Research areas like crop disease detection, soil quality improvement, nanofertilizers and seed germination are still focused areas and researchers attracted towards it. To deal with this fascinating sector, Nanotechnology which is an interdisciplinary research field, is providing platform. For example, advancement in nanofertilizers, which are having high absorption efficiency into the targeted plant due to high surface to volume ratio. The use of phosphorus nano-fertilizers, absorption efficiencies of up to 90.6% achieved. Another beneficial aspect of using nanofertilizers is the ability to provide slow release of nutrients into the plant over a period of 40-50 days, rather than the 4-10 days period of conventional fertilizers. In the present article, we have briefly discussed application of nanotechnology in an agricultural perspective. Herein, we have summarized the applications of silver (Ag) nanoparticles in agriculture such as crop productivity, crop disease detection, food packaging, soil quality, etc.
Materials
Nanotechnology and nanomaterials, including silver nanoparticles (AgNPs), are increasingly important in modern science, economics, and agriculture. Their biological activity involves influencing plant health, physiological processes, growth, and yields, although they can also be toxic in the environment. A new fertiliser was made based on a urea solution with a relatively low content of AgNPs obtained by the reduction of silver nitrate V. Laboratory tests were used to assess the effect of a fertiliser solution containing 10 ppm AgNPs on the germination of agricultural plant seeds (barley, peas, oilseed rape) and vegetables (radish, cucumber, lettuce) and its foliar application on chlorophyll content, stomatal conductance, and seedling biomass. Field experiments were conducted to assess the effect that a foliar application of 15 ppm AgNPs in working liquid had on physiological plant parameters and yields of rape and cucumber. The AgNPs in the tested fertiliser reduced infestation of ...
Effects of Dissolved Silver and Silver Nanoparticle on Soil Microorganisms
Journal of Soil and Water Sciences, 2017
Silver nanoparticles (AgNPs) are the most commonly used man-made nanomaterial in consumer products. They are merged into a vast collection of products due to their particular broad-spectrum anti-microbial action. On the other hand, their anti-bacterial properties may pose a significant environmental risk. This study was undertaken to assess whether the risk that AgNPs and dissolved Ag pose to soil microorganisms gained from nano-or dissolved-silver forms. The antimicrobial effect of green manufactured AgNPs (46.2±23.2 nm) and Ag + (as AgNO 3) on soil microbes were studied using disc diffusion assay. Soil microbial growth was assessed by the measurement of inhibitory zone area (mm 2) as a function of different AgNPs and AgNO 3 concentrations, 0.00, 250, 500, 1000 and 2000 mgl-1. The results of antimicrobial effect of AgNPs showed 10 fold of magnitude comparing with Ag + at lower concentrations (250 mgl-1). The theoretical predicted unity of inhibition zone ratio for AgNPs/Ag ions implies that AgNPs equates to about 5 times antimicrobial effects of Ag +. Although the current results confirm that Ag antimicrobial effect is a nano-specific effect, different bacteria isolated from different soils should be used to explore their physico-chemical properties in mitigating AgNPs toxicity effects.
Environmental Pollution, 2015
We investigated the effects of silver nanomaterials (AgNMs) on five well-characterized soils with distinct physicochemical properties using two standardized test systems. The carbon transformation test (OECD 217) showed minimal sensitivity whereas the ammonia oxidizing bacteria test (ISO 15685) showed extreme sensitivity over 28 days of exposure. AgNM toxicity was compared with the physicochemical properties of the soils, revealing that toxicity declined with increasing clay content and increasing pH. AgNM toxicity did not appear to be affected by the organic carbon content of the soil. Our results showed that AgNM toxicity cannot be attributed to any single soil property but depends on the same parameters that determine the toxicity of conventional chemicals. Recommendations in the test guidelines for soil ecotoxicity studies are therefore applicable to AgNMs as well as conventional chemicals.
Geoderma, 2018
Long term and inclusive toxicity studies encompassing soil, plants, and organisms are rare in literature for AgNPs. This study examines AgNP behavior in soil-plant system through 72 weeks long soil experiment, earthworm response, and plant metabolic analysis. AgNP exposed earthworms did not show reproductive failure; yet high oxidative stress and reduced protein synthesis led to significant weight loss. Such stress was highest with AgNP 50 exposure. Correspondingly, the 50 ppm exposure of AgNP was capable to reduce nutrient availability and microbial growth in soil. Contrary to previous reports, we demonstrated that dissolution rate of AgNP increased with time in soil. Dynamic Light Scattering and UV-VIS assessments exhibited concentration and time dependent agglomeration of AgNP in soil and aqueous media. Moreover, lab based experiments in aqueous medium revealed that significant reduction in silver availability was due to formation of Ag 2 S or Ag 3 PO 4 ; which also greatly affected the P and S availability. Although the vegetative growth of tomato was normal, AgNP (10 mg kg − 1) treatment markedly upset the fruit yield. The 10 mg kg − 1 AgNP exposure significantly enhanced oxidative stress and Ag uptake in plants; consequently, retarded N-assimilating enzyme (glutamate synthase, glutamine synthetase, and nitrate reductase) activity by suppressing their genes in plants. Eventually, photosynthesis and CO 2 assimilating efficiency were severely disrupted. These assays were vital to appreciate the true toxicity and are not well attended in most of the studies with AgNPs.
The Mobility of Silver Nanoparticles and Silver Ions in the Soil‐Plant System
Journal of Environmental Quality, 2019
The widespread use of silver nanoparticles (AgNPs) as a bactericide will ultimately result in their increased concentration in soils. We sought to determine the likely mobility, toxicity, and plant uptake of Ag applied to soil as either AgNPs or Ag+. We measured the solubility, toxicity, and plant uptake of both AgNPs and Ag+ in an immature Pallic soil, a Templeton loamy silt (pH = 5.1), and a granular silt loam (pH = 6.0). The sorption of AgNPs by the test soils was significantly greater than Ag+, and both moieties were more strongly sorbed at lower concentrations and higher pH values. Between pH 4 and 8, distribution coefficient (KD) values increased from <10 up to ∼500 L kg−1 for Ag+, and from 100 to 10,000 L kg−1 for AgNPs. There was strong evidence that our citrate‐coated AgNPs were transformed into Ag+ during the course of the plant growth experiments, and plant responses were similar for both the Ag+ and AgNP treatments. Soil concentrations >100 mg kg−1 significantly re...
Silver Nanoparticle’s Toxicological Effects and Phytoremediation
Nanomaterials, 2021
The advancement in nanotechnology has brought numerous benefits for humans in diverse areas including industry, medicine, and agriculture. The demand in the application of nanomaterials can result in the release of these anthropogenic materials into soil and water that can potentially harm the environment by affecting water and soil properties (e.g., soil texture, pH, organic matter, and water content), plants, animals, and subsequently human health. The properties of nanoparticles including their size, surface area, and reactivity affect their fate in the environment and can potentially result in their toxicological effects in the ecosystem and on living organisms. There is extensive research on the application of nano-based materials and the consequences of their release into the environment. However, there is little information about environmentally friendly approaches for removing nanomaterials from the environment. This article provides insight into the application of silver na...