Abstract
This paper examines fertilizer material circulation through the analysis of fertilization technology in
everyday life and presents some insights into its usage in different parts of society.
With the advent of the modern era, rapid modernization, and population explosion, night soil usage and
human waste treatment facilities exist side by side. The circulation of fertilizer from farm villages to urban areas
and back to farm villages was accomplished in four phases.
In the first phase, in 1900, the government began to participate in the treatment of human waste. As a
result of this, farmers could no longer get free night soil. However, farmers continued to restore night soil to
agricultural land.
In the second phase, the city of Nagoya began to process human waste into ammonium sulfate because
of the city’s expansion and innovations in chemical fertilizer processing plants. But, as this business did
not produce a profit, the plant was closed because of the noxious odors it produced. However, there was an
increasing demand for night soil in order to recover its nutrients to produce fertilizer for year-round vegetable
cultivation. Also, advances in technology, storage, and human waste fertilization were made possible by vast
scientific improvements.
In 1921, with the third phase, Nagoya again started to treat human waste. No longer did the human
waste market lose value because of the increase in population and the resultant surplus of human waste. On
the other hand, in farm villages, utilization of night soil reduced the amount of money expended for agricultural
fertilizer expenses. It stabilized the farmers’ economy.
Nagoya, in the 1930s, again tried to build a sewage treatment plant. However, because of the financial
panic, the demand for a self-supplied fertilizer increased again, and the sewage treatment plant ran into
difficulties. So, the use of night soil in farming areas was reestablished and the process came full circle.
