Eco-evo-nomic approach to sustainable agriculture

The seminar will take place on Friday 26, 2pm at Lynn Margulis.

Zoom link : https://inrae-fr.zoom.us/j/96050116799

Contact : philippe.remigi@inrae.fr

Abstract

For more than ten thousand years, agriculture has been a large-scale experiment in artificial selection. Yet every intervention that improves crop productivity also changes the ecological and evolutionary environment in which crops, pathogens and weeds interact.

In this talk, I explore how this tension between immediate gains and long-term outcomes can be understood using a common theoretical framework spanning crop rotation, resource renewal, resistance evolution and landscape-scale disease management. Using theoretical models, sometimes abstract and sometimes heavily parameterised by empirical work, we show in general that that strategies that appear costly in the short term often outperform seemingly optimal alternatives over longer timescales. Specifically, rotating cover and cash crops sustains yield because cover crops renew the soil while also interrupting pathogenic spread, and switching between two individually losing strategies can combine into a winning one. In weeds, the cost of resistance, self-pollination and the seed bank determine whether and when control fails, and herbicide mixtures outperform rotations and single treatments. At the landscape scale, the cost of resistance is counterintuitive: it falls as chemicals become more expensive and peaks at intermediate pathogen spread.

Combining ecological, evolutionary and economic dynamics reveals that sustainable management is not a compromise between productivity and conservation, but a consequence of optimising biological systems over the timescales on which they evolve.