Reducing the use of plant protection products and greenhouse gas emissions in arable farming systems in northern France (System-Eco+).

Crop protection and nitrogen fertilizers uses are the mainstays of large-scale cereal and industrial cropping systems in northern France. Biological and climatic effects call to design and evaluate cropping systems that cut the use of plant protection products by implementing counterbalancing agronomic levers aiming to maintain yields. An experimental set-up composed of 7 cropping systems located at the Estrées-Mons agronomic station (France) was monitored from 2018 to 2024. The experiment combined decrease in the use of plant protection products while improving the greenhouse gas (GHG) balance by reducing synthetic fertilization. The introduction of cropping systems designed to reduce the use of pesticides made it possible to achieve treatment frequency index (TFI) reductions of 70 to 100% without significantly affecting yields and while ensuring weed control. This also resulted in a significant reduction in fungicide and herbicide residues in the soil. The levers used to reduce the use of plant protection products have a neutral effect on greenhouse gas emissions, or even a favourable effect when leguminous crops are introduced into the succession to provide soil cover and balance the nitrogen balance.