NITROGEN LEACHING IN ECOLOGICAL AGRICULTURE - SUMMARY AND RECOMMENDATIONS

In October 1993 an international workshop on nitrogen leaching in ecol ogical agriculture was held at the Royal Veterinary and Agricultural U niversity in Copenhagen, Denmark. This paper summarizes the discussion at the workshop and outlines recommendations and conclusions. The pap er identifies key factors of major importance to a consideration of ni trogen leaching from ecological agriculture. These are: the farming sy stems approach: management of nitrogen resources at the farm and field level; the research methodology adopted to study nitrogen leaching; a nd finally the need to consider the problem of nitrogen leaching from a rotational perspective taking account of the heavy reliance on N fer tilizers of conventional systems, which in turn leads to environmental , social and ethical problems. It is recommended to emphasize research work aimed at improving and developing ecological farming systems, in order to improve the ability of ecological agriculture to meet define d agronomic, economic, environmental, social and ethical criteria. Fur thermore, it is recommended to encourage initiation of research in nit rogen supply and cycling in ecological farming systems and to organize further workshops aimed at intensifying cooperation and exchange in r esearch work. It is concluded that there is a considerable potential f or ecological farming systems to offer a viable approach to limit nitr ate leaching whilst also meeting the requirements of broader goals of sustainability.