Conversion from conventional to biological dairy farming: Economic and environmental consequences at farm level

Biological dairy fanning is often advocated as a solution for environmental problems caused by Dutch dairy farming. At the same time, biological farmi ng can improve animal welfare and increase income due to a higher milk pric e. In this paper the central issue is to quantify economic and environmenta l consequences for dairy farms when converting to biological daily farming. A linear programming model is used to model an extensive and an intensive dairy farm typical for the Province of Utrecht, The Netherlands. The object ive function of the model maximizes labour income of the farm From the resu lts it appears that the extensive farm benefits from conversion while the i ntensive farm loses income. The environmental consequences are quite divers e. The nitrogen surplus after conversion is much lower than before because nitrogen fixation by legumes is omitted from the calculation. On the other hand, ammonia emission is higher after conversion to biological farming due to a higher number of animals. On the extensive farm the phosphate surplus in the biological situation is much higher than in the conventional situat ion due to the fact that a shortage of nitrogen in the biological situation can only be made up by applying animal manure (slurry) from other farms wi th consequential overfertilization of phosphate. When environmental legisla tion is introduced, the biological farms appear to lose more income than th e conventional farms. From the sensitivity analysis it appears that assumpt ions about milk yield per cow and milk price are crucial for the economic r esults of biological farms.