Permalink : http://hdl.handle.net/2115/57356

The objective of this paper is to compare the environmental performance of conventional and organic dairy farming in Japan. We made comparisons between conventional and organic dairy farming at the farm level in terms of nitrogen and phosphorus surplus per hectare of farmland. To estimate the environmental loads associated with the application of nitrogen and phosphorus, we used the farm gate balance, which measured the difference between the nutrient content of farm inputs and the nutrient content of farm outputs. Five organic dairy farms in region A in Japan were analyzed in the present paper. They acquired the certification for organic roughage production in 2004 and started to produce certified organic milk in 2006. The results of the present paper are as follows. First, the nitrogen surplus per ha of the organic dairy farming system was lower than that of the conventional dairy farming system. Second, the phosphorus surplus per ha of the organic dairy farming system was higher than that of the conventional dairy farming system.