In 2011 Green Economy was announced as one of two main themes of the Rio+20 Conference. Through the preparatory process, the title of the theme was rephrased as "the Green economy in the context of sustainable development and poverty eradication". The issues of food security and agriculture have thus gained more weight and legitimacy in the negotiation process. As the FAO puts it in its "Greening Economy with Agriculture" initiative, "there will be no green economy without agriculture". We look at the role given to agriculture in the Green Economy discourses, and the different models of agriculture promoted by its main institutional actors. Agriculture appears either as a domain for applying the Green Economy, or as a special leverage tool for greening the economy. Through content analysis of the texts produced in preparation of the conference, as well as key texts of institutional actors identified at the RIO+20 Conference, we analyze in greater depth the role given to farmers, knowledges and technologies, to the production (or consumption) of ecosystem services in the models of agriculture proposed actually. We analyze the contradictions between conventional and traditional agricultures. We look at the scales at which the problems of hunger are framed, the metrologies and temporalities used to support the "models" (which can be both examples to follow or the product of a modeling activity). We hope to contribute to the identification of levers for the development of farming options suitable to face the challenge of sustainably feeding the people on Earth.