Reducing the nitrogen load to the baltic sea by increasing the efficiency of recycling within the agricultural system: experience of ecological agriculture in Sweden and Finland

摘要

Agreements to halve the quantities of nutrients reaching the marine environment by 1995 were entered into within the Helsinki Commission (base year 1987) and at the North Sea Conference/Paris Commission (base year 1985). This goal has not been achieved. Agriculture has contributed substantially to an increase in nutrient leaching. Studies of plant nutrient flows and balances at the farm level (different types of farms), county level and country level were made in Sweden for the years 1990 and 1995and, to some extent, in Finland to explain the high losses of plant nutrients in agriculture today, and to describe how, with the technological resources available today plant nutrients could be handled more effectively and there-by minimizing losses ofnitrogen and phosphorus to the environment. The results of the studies indicate that the local and regional specialization of farms is one important reason for the high losses of plant nutrients that are occurring: one type of farm specializes in crop production based on the use of artificial fertilizers, while another specializes in livestock production with large inputs of purchased fodder and a surplus of nutrients in the form of animal manure. The arable farm mainly produces fodder. This fodder andthe nutrients it contains are exported to the intensive livestock farms, where a surplus of manure and urine, and hence of nutrients, accumulates, causing nutrient losses to the environment. By integrating crop and animal production on a farm or farms inclosed cooperation it is possible to maximize the efficient use of nutrients in manure, minimize inputs of nutrients, minimize nutrient surpluses and, as a consequence, minimize losses of nitrogen and phosphorus. By applying these agricultural principles throughout the Baltic region it should be possible to halve nitrogen losses and minimize losses of phosphorus, thereby meeting the goals set by the states of the region.