From 1976 to 1982 he was professor of the "Land, Air and Water Resources Department” at the University of California (Davis, USA). In 1982 he returned to Spain to take the chair of Plant Production at ETSIA, University of Córdoba. Between 1996 and 2000 was director of the Institute for Sustainable Agriculture (CSIC).
During the 80s he participated actively in the definition of the Spanish science and technology model: He was Commission Coordinator of Agricultural Sciences (1983-1985), Director of Special Programmes CAICYT (1985-1987) and Chairman of Engineering the CNEAI (1989). From 1992 to 1994 he headed the State Secretariat for Universities and Research at the Ministry of Education and Science.
He has been highly active in the international arena, working as a consultant to the U.S. Congress Office of Technology Assessment, for the U.S. Agency for International Development and United Nations Organization for Food and Agriculture Organisation (FAO.) From 1998 to 2003 was a member of the Scientific Council of the International Agricultural Research Consultative Group.
He has published over 150 articles in international journals and various book chapters. Since 2001 he has been co-editor of Irrigation Science (Springer Verlag).
He is a member of the Royal Academy of Engineering (1994), of which he was president from 1995 to 2003. From 2000 to 2002 he was president of the European Society of Agronomy.