Syno'phyt : Developing cropping systems for monogastric livestock with low use of pesticides in Brittany.

From 2018 to 2023, three cropping systems with low use of pesticides were co-designed within the DEPHY EXPE 2 Syno'phyt project with various stakeholders and experimented for 5 years: a "Reference 2025" (SR) system with corn-wheat rotation, an "agroecological" system (SA) integrating protein crops and an "organic farming" system (SAB). Tested at the Kerguéhennec station (56), they showed generally satisfactory agronomic performances, although the control of weeds, particularly perennial weeds in SAB, remains a challenge. The average gross margins over 5 years were 1066 ± 187 €/ha for SAB, 1001 ± 138 €/ha for SR and 895 ± 96 €/ha for SA. Working time was higher in SR (7h36/ha) than in the other systems (6h29/ha and 6h44/ha in SAB and SA respectively). The results of this trial showed that, in conventional agriculture, the reduction of pesticides is possible without lengthening the rotation but at the expense of working time. Questions persist regarding the structuring of sectors for the promotion of "minor" crops.