What lessons can be learned from the atrazine ban in the context of the future withdrawal of glyphosate?

Over the past seventy years, some herbicides have become ``keystone'' active ingredients in weed management. In France, until 2003, atrazine played a key role for maize weeding. Since 1974, glyphosate has become the most used herbicide for intercropping period management and has become central for conservation agriculture. Such exceptional efficiency and a low cost placed atrazine and glyphosate among the most used herbicides worldwide. In either case, their over-use has contributed to water pollution and to the emergence of questions about possible negative effects on the environment. An agronomical, economical and societal comparison between the withdrawal of atrazine and glyphosate showed similar concerns of agricultural sector about weed management. The withdrawal of atrazine may have increased costs of maize weeding, but weed communities have been successfully managed, mainly thanks to the use of other chemical ingredients. The possible glyphosate ban, planned in France in a near future, may have strong impacts on weed management and more generally on farm operations. The main available alternative to glyphosate is soil tillage, but other agronomical practices have to be associated to maintain an effective weed management. Although 15 years apart, the withdrawal of these two active ingredients allows to put emphasis on the impacts that a massive use of a unique chemical ingredient can have on the environment and on the adaptability of agricultural systems.