Current agricultural practices, developed during the green revolution, are becoming unsustainable, especially in the face of climate change and growing populations. Nanotechnology will be an important driver for the impending agri-tech revolution that promises a more sustainable, efficient and resilient agricultural system, while promoting food security. Here, we present the most promising new opportunities and approaches for the application of nanotechnology to improve the use efficiency of necessary inputs (light, water, soil) for crop agriculture, and for better managing biotic and abiotic stress. Potential development and implementation barriers are discussed, emphasizing the need for a systems approach to designing proposed nanotechnologies.

Opportunities and challenges for nanotechnology in the agri-tech revolution.

Various nano-enabled strategies are proposed to improve crop production and meet the growing global demands for food, feed and fuel while practising sustainable agriculture. After providing a brief overview of the challenges faced in the sector of crop nutrition and protection, this Review presents the possible applications of nanotechnology in this area. We also consider performance data from patents and unpublished sources so as to define the scope of what can be realistically achieved. In addition to being an industry with a narrow profit margin, agricultural businesses have inherent constraints that must be carefully considered and that include existing (or future) regulations, as well as public perception and acceptance. Directions are also identified to guide future research and establish objectives that promote the responsible and sustainable development of nanotechnology in the agri-business sector.

Nano-enabled strategies to enhance crop nutrition and protection.

Application of nanoparticles in biofuels: an overview

Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nanobiotechnology, combined with green chemistry, has great potential for the development of novel and necessary products that benefit human health, environment, and industries. Green chemistry has an important role due to its contribution to unconventional synthesis methods of gold and silver nanoparticles from plant extracts, which have exhibited antimicrobial potential, among other outstanding properties. Biodiversity-rich countries need to collect and convert knowledge from biological resources into processes, compounds, methods, and tools, which need to be achieved along with sustainable use and exploitation of biological diversity. Therefore, this paper describes the relevant reported green synthesis of gold and silver nanoparticles from plant extracts and their capacity as antimicrobial agents within the agricultural field for fighting against bacterial and fungal pathogens that can cause plant, waterborne, and foodborne diseases. Moreover, this work makes a brief review of nanoparticles’ contribution to water treatment and the development of “environmentally-friendly” nanofertilizers, nanopesticides, and nanoherbicides, as well as presenting the harmful effects of nanoparticles accumulation in plants and soils.

Green Synthesis of Gold and Silver Nanoparticles from Plant Extracts and Their Possible Applications as Antimicrobial Agents in the Agricultural Area.

Nanotechnology offers potential solutions for sustainable agriculture, including increasing nutrient utilization efficiency, improving the efficacy of pest management, mitigating the impacts of climate change, and reducing adverse environmental impacts of agricultural food production. Many promising nanotechnologies have been proposed and evaluated at different scales, but several barriers to implementation must be addressed for technology to be adopted, including efficient delivery at field scale, regulatory and safety concerns, and consumer acceptance. Here we explore these barriers, and rank technology readiness and potential impacts of a wide range of agricultural applications of nanotechnology. We propose pathways to overcome these barriers and develop effective, safe and acceptable nanotechnologies for agriculture. Nanotechnology holds great application potential in plant agriculture. This Review Article identifies the technological readiness, addresses the primary barriers to adopting nano-enabled technologies and proposes a roadmap to advance nanotechnology-enabled agriculture.

Technology readiness and overcoming barriers to sustainably implement nanotechnology-enabled plant agriculture

Several types of engineered nanoparticles (ENPs) are being considered for direct application to soils to reduce the application and degradation of pesticides, provide micronutrients, control pathogens, and increase crop yields. This study examined the effects of different metal ENPs and their dissolved ions on the microbial community composition and enzyme activity of agricultural soil amended with biosolids. The activity of five extracellular nutrient-cycling enzymes was measured in biosolid-amended soils treated with different concentrations (1, 10, or 100 mg ENP/kg soil) of silver (nAg), zinc oxide (nZnO), copper oxide (nCuO), or titanium dioxide (nTiO2) nanoparticles and their ions over a 30-day period. At 30 days, nZnO and nCuO either had no significant effect on soil enzyme activity or enhanced enzyme activity. In contrast, Ag inhibited selected enzymes when dosed in particulate or dissolved form (at 100 mg/kg). nTiO2 either had no significant effect or slightly decreased enzyme activity. Illumina MiSeq sequencing of microbial communities indicated a shift in soil microbial community composition upon exposure to high doses of metal ions or nAg and negligible shift in the presence of nTiO2. Some taxa responded differently to nAg and Ag+. This work shows how metal ENPs can impact soil enzyme activity and microbial community composition upon introduction into soils amended with biosolids, depending on their type, concentration, and dissolution behavior, hence providing much needed information for the sustainable application of nanotechnology in agriculture.

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Amendment of Agricultural Soil with Metal Nanoparticles: Effects on Soil Enzyme Activity and Microbial Community Composition.

Engineered nanoparticles (ENPs) are introduced to the soil environment mainly via wastewater biosolids applied to soils and their targeted delivery in agricultural applications. The impact of ENP size and surface coating on the activity of extracellular enzymes and bacterial community composition of an agricultural soil was examined using model gold nanoparticles (nAu). These endpoints were chosen as indicators of the soil's response to external disturbances. The activity of five extracellular enzymes important in nutrient-cycling was measured in soils treated with commercially available 50 nm citrate-coated nAu and polyvinylpyrrolidone (PVP)-coated nAu of three different nominal diameters: 5, 50, and 100 nm. At low particle concentration (0.1 mg nAu kg−1 soil), decreasing the size of PVP-nAu resulted in an increased stimulation of soil enzyme activity. No correlation between size of PVP-nAu and soil enzyme activity was observed at a higher dose (100 mg nAu kg−1 soil). At a fixed size of 50 nm, citrate-coated nAu generally resulted in significant increases in soil enzyme activity at 30 days of exposure compared to PVP-coated nAu. Data from 16S rRNA gene sequencing showed that the community composition of soil spiked with citrate-coated nAu clustered significantly away from soil spiked with PVP-nAu at higher concentration (100 mg nAu kg−1 soil), showing the effect of type of nAu surface coatings. Abundance of bacteria annotated to operational taxonomic units (OTUs) from important soil bacterial groups, including Actinobacteria and Proteobacteria, increased following exposure of soil to nAu and more substantially following exposure to citrate-coated nAu for 30 days. This study shows that release of nanomaterials such as nAu to soils may have significant effects on soil enzyme activities and microbial communities and thus impact nutrient cycling in soils. Moreover, this study provides baseline knowledge that may be useful in customizing nanoparticle size and surface coating for their potential use as nutrient delivery agents in agriculture.

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Effect of gold nanoparticles on extracellular nutrient-cycling enzyme activity and bacterial community in soil slurries: role of nanoparticle size and surface coating

Vanessa Cianciarelli

Papers

Amendment of Agricultural Soil with Metal Nanoparticles: Effects on Soil Enzyme Activity and Microbial Community Composition.

Effect of gold nanoparticles on extracellular nutrient-cycling enzyme activity and bacterial community in soil slurries: role of nanoparticle size and surface coating

Correction to "Amendment of Agricultural Soil with Metal Nanoparticles: Effects on Soil Enzyme Activity and Microbial Community Composition".