Producing safe food could be achieved in a sustainable way by changing agricultural practices. However, there is actually a lack of suitable methods and indicators that measure sustainability. This lack of knowledge is particularly deep at the farm level in poor countries that represent most food production worldwide. In addition, actual indicators are defined only by scientists, thus not taking into account essential farmer knowledge. Using participatory indicators designed with farmers Yegbemey et al. reveal weaknesses of maize cropping in Benin. This knowledge can be used to set up sustainable cropping practices.