UMR ECOSYS has been working for 30 years on alternatives to intensive agriculture. Based in the Yvelines in an area of arable farming with no livestock and high levels of urban waste production, this team, led by Sabine Houot, studies the use and fate of waste products and chemical inputs on farms. The research focuses on plant-soil-water-air relationships and is based on a network of experimental plots of land: SOER PRO. The considerable amount of data and knowledge generated by this network now makes it possible to think about and implement the agro-ecological transition.