Improvement of Livestock Waste Treatment and its Impact on Water Quality in Lake Kasumigaura Basin

Abstract

This study is focused on a water pollution load from livestock waste. Water pollution caused by livestock waste is an important problem which affects life and global environment. "The law concerning the appropriate treatment and promotion of utilization of livestock manure" was partially enforced to promote proper treatment of livestock waste in 1999, and was completely enforced in 2004. In this study, we analyzed how the law had influenced the ways of livestock waste treatment in Lake Kasumigaura basin. In addition, we grasped the flow of nitrogen by constructing nitrogen flow model. According to the result, the law contributed to the reduction of inappropriate treatment. However, the amount of nitrogen spread over the field was increased and flow balance was getting worse.