MANURE LEGISLATION EFFECTS ON INCOME AND ON N, P AND K-LOSSES IN DAIRY FARMING

In this paper the central issue is to quantify the consequences of actual and proposed government policies on the labour income and the losses of N, P and K on grassland dairy farms situated on sandy soil. Moreover the question of whether the Dutch governmental objectives for the year 2000 (namely a reduction of at least 50% of losses of ammonia, nitrate and phosphate compared to 1980) can be reached in dairy farming will be discussed. A linear programming model is used to model some typical dairy farms. The objective function of the model maximizes labour income of the farm. The most important decision variables affecting nutrient use and nutrient losses are: the animal density on the farm, the feed ration of the cows and young stock, the method and length of storing manure, the method of applying manure to the land, whether the land is used for grassland or fodder crops and the level of nitrogen application on grassland. The results show that all government policies have a negative influence on labour income. The most severe policies cause reductions in labour income of Dfl. 244 per hectare on extensive farms up to Dfl. 532 on intensive farms in the year 2000. Of the nutrients, only N-losses are decreased considerably, namely with 11 kg per hectare on extensive farms up to 208 kg per hectare on intensive farms.