Crop management strategy redesign enables a reduction in reliance on pesticides: A diachronic approach based on a diversity of French commercial farms
Résumé
Pesticides are widely used in agriculture to manage pests, weeds and diseases with consequences on ecosystem and human health. Reducing pesticide reliance appears as a necessary step for transitioning to sustainable farming systems. Many non-chemical techniques to control pests, weeds and diseases are individually well documented, but quantitative assessment of how much the reliance on pesticides could be decreased through a holistic approach of cropping system re-design combining several individual techniques was lacking. A diachronic approach was conducted on 913 French commercial farms from the DEPHY network, spanning a diversity of contexts and management strategies. Regression Trees and Random Forest models were run to identify combinations of changes in management strategies associated with the evolution of pesticides reliance over time, in a range of production contexts. The consequences of these changes on pesticide-related risks to human health and the environment were also investigated. Farm reliance on pesticides and pesticide-related risks to human health and the environment were reduced in 65.7% and 60.3% of the farms, respectively. The greatest reductions in pesticide reliance were observed in farms with the highest initial levels of reliance on pesticides. Crop diversification and reduced nitrogen fertilization were often associated with reduced pesticide reliance. This study highlights the value of real farm networks for identifying and promoting combinations of techniques that help reduce pesticide dependency and move towards more sustainable farming systems.