This study takes an in-depth look at the arable crops sector in OECD countries and draws some conclusions about the impacts of agricultural support policies, trade liberalisation, agri-environmental payments, and agri-ennvironmental regulations. It contains economic and structural data, agri-environmental indicators for the arable crops sector, and analysis of the policy measures supporting arable crops farming and addressing environmental issues both at the aggregate country level and regional levels. This is the third in a series of in-depth studies being undertaken by the OECD to investigate the linkages between agriculture, trade and the environment. The first study on the pig sector was published in 2003, and the second study on the dairy sector was published in 2004.