Putting the concept of environmentally balanced fertilizer recommendations into practice on the farm

The intermediate meeting of the Ministers North Sea Conference was held in Copenhagen during December 1993. The Declaration published as a result of that meeting places particular emphasis on the need to define the exact meaning of balanced fertilizer recommendations and the objective to implement these, preferably by the year 2000, but no later than the year 2002. The progress of this work will be the responsibility of the Oslo and Paris Commissions, OSPARCOM. As a member of OSPARCOM the Commission of the European Union has been specifically asked to play an active role in the work. In the autumn of 1991, the International Fertilizer Association (IFA) and the European Fertilizer Manufacturers Association (EFMA) organised a conference which was attended by representatives from academic institutions and the fertilizer industry. It resulted in the drawing up of a Code of Best Agricultural Practices to optimize fertilizer use. Central to the code is the efficient use of plant nutrients, which requires fertilizer recommendations to be site specific and to take full account of available nutrient supplies and crop offtakes within the context of prevailing environmental constraints. The fertilizer industry believes that the proper application of Codes of Best Agricultural Practices is a key factor in achieving balanced fertilization. This paper is a logical progression of the 1991 work. It provides information on the factors to establish a framework for determining fertilizer recommendations which result in the efficient use of plant nutrients. These are: the nutrient offtake by the crop; the characteristics of each of the available sources of nutrients; the biological, chemical and physical processes within the soil which are essential to plant nutrition. The information provided in the paper demonstrates that to establish recommendations and therefore arrive at balanced fertilization, these need to change in accordance with the varying climatic and soil conditions. Finally, the paper discusses how such a framework can become the basis of the individual farmer's decision-making. Overall, the emphasis is on putting existing research results into practice on the farm.