Abstract
To assess environmental risks related to the mobility and toxicity of AgNPs, the chemical availability of AgNPs and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) in three agricultural soils was quantified in a pot experiment. Porewater collection and soil extractions with 0.01 M CaCl2, 0.4 M Glycine (pH 1.5) and 0.05 M NH4-EDTA were performed. The effect on soil exoenzyme activities was also assessed. Porewater concentration was low (<0.4% and <0.04% of dosed Ag, for AgNPs and PVP-AgNPs, respectively) and only detected in acidic soils (pH 4.4 and 4.9). The PVP-coating reduced the downward mobility of AgNPs in soil and possibly also their dissolution rate (and subsequent release of dissolved Ag+ ions into porewater). The effect of variation in organic matter on soil enzymatic activity was larger than that of AgNPs, as no significant additional inhibitory effect from Ag could be observed. Only at low pH and in the presence of complexing ligands that form very stable Ag complexes (0.4 M Glycine extraction at pH 1.5) up to 58% of the Ag added to soil was released (independently of PVP coating). An extraction with glycine is proposed as a useful indicator of potentially available Ag in soils.
Highlights
There is a growing development and use of nano-enabled products in agriculture due to their increased activity associated with the small size and to the potential for reduction of the amount of applied active ingredients [1,2,3]
Suggested advantages on the use of AgNPsenabled fungicides compared to AgNO3 or to conventional formulations relate to higher efficacy at lower application doses (15 g AgNPs ha−1, compared to commonly applied doses of 105 g ha−1 to 6 kg ha−1, for conventional fungicides), and reduction in human toxicity [8,10,11,12]
Measured in 0.01 M CaCl2 ranged from pH 4.4 to 6.3 which is representative for agricultural soils from industrial, mining and rural areas in Portugal [34,56]
Summary
There is a growing development and use of nano-enabled products in agriculture due to their increased activity associated with the small size and to the potential for reduction of the amount of applied active ingredients [1,2,3]. Potential applications of AgNPs as fungicides in agriculture have been investigated [8,9]. These were proven effective against pathogenic fungi which commonly affect crops such as corn, barley and rice or against mildew infestation on roses [10,11,12]. Suggested advantages on the use of AgNPsenabled fungicides compared to AgNO3 or to conventional formulations relate to higher efficacy at lower application doses (15 g AgNPs ha−1 , compared to commonly applied doses of 105 g ha−1 to 6 kg ha−1 , for conventional fungicides), and reduction in human toxicity [8,10,11,12]. Suggested advantages on the use of AgNPsenabled fungicides compared to AgNO3 or to conventional formulations relate to higher efficacy at lower application doses (15 g AgNPs ha−1 , compared to commonly applied doses of 105 g ha−1 to 6 kg ha−1 , for conventional fungicides), and reduction in human toxicity [8,10,11,12]. 4.0/).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
