ChiNor solutions for Low Impact climate smart vegetable production with reduced pesticide residues in food, soil and water resources

The LowImpact project has aimed to develop combined solutions for a climate-smart production practice with a reduced negative impact on soil quality, the environment and food safety. We have focused on the use of plant protection agents (pesticides) and emissions of greenhouse gases in vegetable production and the potential for biochar-based solutions to reduce the environmental impact. To improve the tools available to study persistence and occurrence of pesticides in food and the environment, a non-target suspect screening method for 850 pesticides and metabolites in soil and vegetables was developed at NIBIO on a QExactive orbitrap MS at the start of the project. This method was used to map pesticide residues in soil in field trials with carrot and potato in Norway. IPP-CAAS correspondingly developed a screening method based on QTOF technology which was used for screening both soil and plants in Chinese field trials. The project has benefitted from the expertise at the University of Almeria in the development and use of such screening methods. An assessment was made of how well the model PERSAM calculates concentrations of pesticides in soil under Norwegian conditions in the short and long term. This model has recently been included in the model suite used for the authorization process for plant protection products. The assessment was done by use of results from the field trials in the project and comparing with another available model. However, a lot more data on pesticides in Norwegian soil is required to be able to be able to conclude. The project partner at SINTEF ER produced biochar for use in laboratory experiments in the project and a detailed characterization of this material has been peer-reviewed. Maize was chosen as raw material due to the necessity of having plant material with isotopic C4 signature to trace the CO2 origin in microcosm studies and the availability of this raw material in both China and Norway. Soil microcosm studies of possible interactions between pesticides, biochar and the release of nitrous oxide was carried out at NIBIO and the results show clear interactions between biochar and residues of pesticides in soil in their effects on the emissions of greenhouse gases. Both the use of pesticides and soil type must be considered as it has an effect on how biochar will affect greenhouse gas emissions from the soil. Different commercially available biochar varieties in China, their sorption properties for pesticides when added to different soil types and their impact on plant growth etc., was investigated at IPPCAAS and peer-review published. Challenges with the persistence of fungicides in the environment and potential formation of toxic metabolites was studied specifically for the fungicide difenoconazole. The studies show fairly rapid photolysis, while degradation in soil is slow and depends on the content of organic matter. This work is peer-review published in collaboration between IPPCAAS and NIBIO and was followed by studies of the toxicity of pesticide metabolites in the aquatic environment. Furthermore, laboratory incubations and pot experiments were carried out at IPPCAAS with selected pesticides and biochars to show the potentiatl benefit of biochar by reducing plant uptake of residual amounts of pesticides in the soil and hence, improved plant growth. Laboratory studies performed at NIBIO to investigate the combined effect of biochar and pesticides on microbial diversity and functionality in soil showed that pesticides affect microbial diversity, however temporary. Biochar had no noticeable effect on this. Although these experiments showed only a transient effect of pesticides and biochar, the study was very limited and only included one pesticide mixture and one type of biochar, making it difficult to generalize from this. This work was supported by the project partner at INRAE Dijon. The dissemination activities included a seminar on the project's contribution to increased food safety and better soil health with participation a.o. from the Directorate of Agriculture and the Chinese Ministry of Agriculture in May 2021 and the final seminar in December 2022 focused on the regulatory framework for pesticides in food and the environment and the results from the project from both the Chinese and Norwegian sides. In collaboration with the Ministry of Foreign Affairs-funded project SinograinII, an information video was made about the importance of good analytical methods and a comprehensive monitoring program for pesticides to ensure safe food on the market. The results are communicated through news items on nibio.no with a focus on pesticides and food safety, biochar as a measure for greenhouse gas emissions, and a summary of the main results. Several papers have been published in collaboration between Norwegian and Chinese partners, and peer-reviewed publications from the laboratory and field trials in Norway will appear in 2023-2024.

Improved tools for exposure and impacts assessment of pesticides in food and environment: The project has developed comprehensive screening tools for the detection of pesticides and metabolites in food and environmental samples based on high resolution mass spectrometry (HRMS) technologies. These tools are already in use in the national research and monitoring programs in Norway and China for food safety and soil monitoring and contributes in the long term to and improved database and provide a better basis for risk assessments in these fields for both research, regulatory and risk assessment bodies. Ultimately, these improved tools for exposure assessment of pesticides will ensure the development of more sustainable food production practices and food safety for the general public in the long term. Further, the project results included novel model approach for plant uptake of pesticides, as well as testing of a new regulatory model approach for pesticide concentrations in soil under northern soil and climate conditions. These tools needs further studies and developments by the research partners, but will in the longer term be able to provide modeling tools better adapted to the regulatory and research needs for the assessment of pesticide impacts in northern soil and climate conditions. New knowledge on pesticide and biochar interactions in soil: The project provides new knowledge on the interactive effects between pesticides and biochar in soil, and the resulting potential impacts on functional soil microbial diversity and GHG emission rates. This provides a starting point for further studies on these topics. More data is needed to enable sufficiently reliable conclusions and recommendations on how best use biochar balancing the concerns regarding pesticides and GHG emissions under different climate and soil conditions and different pesticide use practices. Long term impacts: Better tools to identify the potential exposure and effects of pesticides in cropping systems will, in the long term, result in improved food safety and improved environmental risk assessment. The combination of studies of biochar impacts on GHG emission with climate impacts of those with studies of biochar effects on pesticide fate and impacts will improve the background knowledge necessary to design more/sufficiently holistic solutions for reducing the environmental impact of vegetable cropping. This will benefit policy makers and risk assessors through improved knowledge and methods. The society will benefit directly through healthier foods and lower human health risk and indirectly through reduced impacts on the natural environment and the ecosystem services it provides. In all, the project results will potentially contribute to more sustainable agriculture in the longer term.

Current challenges in agricultural production practices include negative impacts on soil quality, environmental and food safety. Biochar technologies show promise as tools for climate smart and environmentally friendly agricultural production, both as tools to improve soil quality and impact greenhouse gas emission from soils and to reduce pesticide pollution to the environment and pesticide residues in food. However, there is a lack of studies integrating these concerns and designing joint solutions. The LowImpact project aims to develop such combined solutions for vegetable production in Chinese and Norwegian pedoclimates. To achieve this we will (i) develop tools for appropriate exposure assessment of pesticides and metabolites in food, soil and water, (ii) assess pesticide exposure in important agricultural productions in Norway and China, (iii) evaluate effects of biochar on the fate of pesticides, organic C and N in soils, and (iv) characterize impacts of pesticide and biochar use to ensure environmentally friendly production practices. LowImpact is a collaboration between Norwegian and Chinese research partners representing comparable national expertise that will allow for a twinning of studies being performed under the different regulatory frameworks and pedoclimatic conditions, creating solutions that can be extrapolated beyond the limits of each participating country. The project aims to alleviate joint Chinese-Norwegian challenges specific for vegetable production, and will complement and strengthen an already ongoing ChiNor research collaboration addressing challenges in cereal production (the SinoGrain 2 project). The project results will benefit policy makers and risk assessors via improved knowledge and methods. The society will benefit directly through improved food safety and indirectly through reduced impacts on the natural environment and the ecosystem services it provides.