The addition of synthetic nanoparticles (NPs) to plant protection products and fertilisers in agriculture may lead to a reduced use and impact of pesticides and fertilisers in the environment and may increase crop productivity. However, before these advantages can come into play, the risks of NPs for the environment and crops have to be defined to ensure their sustainable and beneficial application.
Background
NPs are currently evaluated as carriers for pesticides and fertilisers. Advantages of formulations containing NPs are for instance optimised pesticide release kinetics, reduced rates of photolysis, as well as applications of smaller amounts of active substances. NPs may even promote seed germination and increase biomass production. To date, the behaviour and effects of NPs in the agro-environment are largely unknown. Specific knowledge gaps exist concerning NP analysis, NP mobility in soils, NP effects on soil microbes and their ecological functions, as well as NP uptake and effects on plants.
Aim
The primary aim is to provide data for risk evaluation of agricultural NP applications. Specifically it will be tested 1) whether NPs accumulate in soils, soil microbes, and crops, and 2) whether NPs affect microbial population structure and key ecological functions performed by symbiotic soil microbes, in particular nitrogen (N) fixation and phosphorus (P) acquisition, and 3) whether NPs affect crop performance, specifically crop yield and quality.
NP exposure, fate and effect studies will be performed in experimental settings of increasing complexity, from laboratory cultures over controlled pot experiment to lysimeter studies with real soils. Two agricultural crops, i.e. wheat and clover, and two groups of symbiotic soil microbes, i.e. N-fixing bacteria (rhizobia), and P-supplying arbuscular mycorrhizal fungi, will be used. NPs potentially relevant for the agro-environment (e.g., TiO2, carbon nanotubes) will be added in increasing concentrations as spray or liquid to crop or soil surfaces, or be mixed homogenously with soil. Based on current works several analytical methods will be developed to monitor NPs in soil, soil leachate, microbes and plants. A series of biological endpoints (e.g. microbial biomass, community structure, N-fixation, P-acquisition, crop productivity) will be determined.
Significance
Our results will contribute to a better understanding of the fate of NPs in agro-environmental systems, and their effects on soil microbes and crops. NANOMICROPS will provide relevant ecotoxicological information on exposure and effects of NPs as a basis for a comprehensive risk assessment.
Original title: Effects of NANOparticles on beneficial soil MIcrobes and CROPS (NANOMICROPS)
Grant: CHF 412'688.-
Duration: 36 months
Project leader
- Dr. Thomas Daniel Bucheli