Context
; Potatoes are one of the most important starchy foods in the world. In Belgium (BE), China (CN) and South Africa (SA), potatoes are a major staple food. From an economic point of view, potatoes are a major vegetable crop: BE is the number one exporter of frozen potato products, CN is by far the largest producer and consumer of potatoes in the world and produces alone a quarter of the world production (Wang et al., 2023), and in SA, potatoes comprise 50% of the value of the total vegetable crop and generates 10% of the employment in the agricultural sector. At the same time, intensive potato production is potentially a major source of the spread of Plant Protection Products (PPP) in the environment, with potential harmful effects on the soil microbiome, and potential health risks for farmers, their families and nearby rural populations. For example, in 2020 the second most sold chemical class of PPP in Belgium were “thiocarbamate herbicides” (243,000 kg active substance), including prosulfocarb (fytoweb.be), which is also detected on all Belgian farmers involved in this study.
; The IMPOCHA project, “Improvement of soil, potato crops, and human health in a context of climate change”, aimed to provide valuable insights into sustainable agricultural practices and to evaluate the impact of PPP on both environment and human health. Furthermore, a second objective was to evaluate the impact of climate change conditions on the microbiome in soil samples taken from potato fields with different cropping methods.

; Objectives
; To assess the impact of potato growing on the environment and human health, under real-world conditions and experimental conditions that mimic climate change.
; To assess the fungicide exposures of farmers and their family (BE and CN) by means of a questionnaire on agricultural practices and fungicide usage. Silicone wristbands will be used as a proxy for human exposure. The fungicides present in the wristband will be analysed and consequent risk assessment will be performed.
; To assess the impact of agricultural practices on the soil microbiome in BE, CN and SA by comparing agricultural practices including pesticide usage on the microbiome in potato soils (using next generation sequencing).
; To assess the effect of different agricultural practices on the forage quality (and thus animal health) in SA, in root cover crops planted after potato crops in the same fields.
; To assess the impact of climate change, growth chamber trials with elevated atmospheric CO2 concentrations and warmer/drier climatic conditions, and greenhouse experiments simulating warmer/drier conditions will be used in BE, CN and SA to evaluate the reaction of soil microbiomes of various quality (diversity) to these new conditions.

; Conclusions
; General objective of the project was to use science to explore methods to improve potato crop farming and estimate the health risk of pesticide use for farmers.
; The project results indicate that climate change can be positive for potato growing, but the benefit will be dependent on the region, and might change the regions suitable for potato growing. It is key that this change is anticipated. We found that biodiversity was not highly affected by fungicide treatment. This unexpected result can be explained in that the project time window might be too short to detect long-term effects.
; The silicone wristband is a passive sampling tool to estimate human exposure to chemicals as an alternative for human sampling. It is a straightforward tool, with a potential to facilitate human exposure assessment for epidemiological population studies. The project has tested and validated this tool for selected plant protection products (PPP) in BE and CN. The project has also provided a protocol for assessing fungicide exposure of farmers and their families. As such, the project has realised a step forward in validating the wristband as a tool for the health monitoring of farmers to replace blood and urine sampling, which is operationally challenging. Using wristbands would allow for more regular monitoring (at least 2x per year) of the exposed population.
; Monitoring soil microbiome is a potential method for assessing the sustainability of cropping practices and in particular the impact of fungicides and other pesticides, as well as the impact of changing climate conditions. A first method is to study the relative diversity of the microbiome and its evolution during a cropping season and between cropping seasons; absolute quantities; some absolute measurements by soil respirometry or other microbiological methods may be necessary to obtain interpretable results.