Florian Christ

Today's agriculture faces many challenges. Due to intensive soil management, the widespread use of pesticides and fertilisers, biogeochemical fluxes are being disrupted, biodiversity is being strained, and soil degradation is becoming a major issue. Therefore, regenerative agriculture (RA), amongst other measures, has gained increasing attention. It aims to improve soil health and ecosystem services, needed to enable reliable food production with fewer negative impacts. However, field research on the impact of RA on the agricultural environment is scarce, especially in Europe. This research therefore investigates that impact, focusing on soil, plant health, and pesticide residues. The investigations took place on oilseed rape cultivated fields in the Swiss Plateau. The results showed a slight trend towards more favourable soil parameter values in the regenerative fields than in the conventional fields. This trend is underlined by significantly higher soil organic carbon values and, once site effects were accounted for, a significantly higher soil health index. The plant parameters showed no clear trend. Pesticide residues in the soil of regenerative fields were generally lower than in conventional fields in terms of the number of substances detected, their concentration and ecological risk, but varied considerably among the RA farms studied. Building on these findings and a review of recent literature, we propose refined, graded criteria for practice-based RA scoring. Together, the results support RA's potential to improve soil health and reduce reliance on pesticides, while highlighting the need for further research into yield trade-offs and a standardised definition of RA.

One of the main challenges in understanding the fate and impacts of pesticides is to incorporate multiple environmental and human matrices and their interrelations. This study aimed to identify the most critical substances through detection frequency (DF) analysis of multiple environmental and biological matrices of Swiss study site containing orchards. A sampling campaign was conducted during the harvest season of 2021 that encompassed conventional and organic farming systems (FS), and 3 population groups (farmers, neighbors, and consumers). We analyzed 208 pesticide residues (active substances and metabolites) in a total of 62 environmental samples (soil, plant, indoor dust, water, and sediment) and 235 human samples (urine, feces, plasma, and wristbands). DDE p,p’ was the substance with the highest DF in environmental samples (61%), followed by dicamba (55%), hexachlorobenzene (52%), difenoconazole (44%), and dieldrin (42%). For humans, 8 of the 20 most frequently detected substances are highly hazardous and 9 are probably hazardous to human health. Among the 6 substances detected in human blood, 2 are hazardous (piperonyl butoxide and hexachlorobenzene) and 2 are probably hazardous (fluopyram and DDE p,p'). Samples from organic FS are less contaminated than samples from conventional systems. Conventional famers showed the highest DFs for several pesticide residues. 25% of compounds including banned substances detected in both compartments illustrates how legacy contaminants continue to dominate in the mixtures and circulate between environmental reservoirs and humans. Integrating pesticide insights from diverse matrices is crucial to advancing our understanding of pesticide exposure and designing more effective risk reduction strategies.