DESIGN PERSPECTIVES IN LONG-TERM EXPERIMENTATION

The aims and design features of historic long-term experiments are discussed and modern perceptions are presented of long-term studies to address sustainability and research impact in farming communities. A research strategy is proposed combining on-station and on-farm research whose results influence dynamically the directions of the component studies. Guidelines are given for choosing well-controlled designs, appropriate data and sampling procedures and for maintaining quality control in data collection and indicator formation over anticipated lengthy periods of time.