## Column

## Night soil prices

In the Edo era, a price was placed on night soil for trading purposes, and these prices varied depending on the person’s class in society. Since the nitrogen and phosphorus contents were an essential determinant of fertilizer quality, it is believed that the value placed on night soil as a fertilizer was determined by the person’s diet.

An analysis of night soil in the early Showa period (performed by Dr. Kerner, professor of the School of Agriculture and Forestry (now the Faculty of Agriculture, the University of Tokyo)) shows that the nitrogen and phosphoric acid contents of night soil differed between people with different jobs, such as farmers and soldiers.

Many local products and specialties emerged during the Edo era. Vegetables were cultivated in and around Edo as local specialties. Nerima radish, Komatsuna greens (produced around Komatsugawa) and Takinogawa burdocks are examples of “Edo vegetables” which satisfied the appetite of Edo people in terms of both quality and quantity. The ability to produce large amounts of this sort of local produce was a major benefit resulting from the effective use of night soil as fertilizer (Figure4-2-2).

## C SMC blocks, according to regional characteristics

Efforts to create a SMC in accordance with regional characteristics were also observed in regions outside Edo. In the Kamigata region, including Osaka and Kyoto, night soil was also utilized and fostered the formation of intraregional material cycles well-suited to regional characteristics. For example, farmers in Settsu and Kawachi contracted with urban dwellers in Osaka in order to collect night soil for use as fertilizer. Another example of the utilization of night soil was found in the domain of Kaga (governed by the Maeda clan).

As shown by these selected cases, SMC blocks were established in many parts of Japan in a way that took full advantage of regional characteristics.

## (2) Systems for appropriate waste disposal

A typical example of waste disposal in the Edo era, and one that may still be applicable to today’s society, is the system by which government-authorized contractors collected waste and carried it to final disposal sites in order

Composition of night soil (\%)

Contents	Class	Farmer	Tokyo citizen	Middle class gov. official	Military person
Water	95.4	95.4	94.5	94.6	94.6
Organic matter	3.03	3.18	3.89	4.07	4.07
Nitrogen	0.55	0.59	0.57	0.80	0.80
Phosphoric acid	0.12	0.13	0.15	0.30	0.30
Potassium	0.30	0.29	0.24	0.21	0.21
Soda	0.51	0.41	0.45	0.26	0.26
Lime	0.01	0.02	0.02	0.03	0.03
Magnesium	0.03	0.05	0.06	0.05	0.05
Sulfuric acid	0.07	0.04	0.05	0.07	0.07
Chlorine	0.70	0.55	0.61	0.51	0.51
Silicic acid & sand	0.04	0.10	0.11	0.04	0.04
Iron oxide & aluminite	0.03	0.02	0.06	0.06	0.06

Source: Kazue Kurokawa, "A Study of Soil Fertilizers since the Meiji Era in Japan"

to ensure its appropriate disposal. Establishing such a system for the correct disposal of waste is a necessary prerequisite to forming a SMC.

## A Edo's waste disposal system

The initial waste disposal method used in Edo was the dumping of waste within the grounds of each residence or in empty lots, rivers and moats. Another dumpsite was a place called the "kaisho-chi," which was a vacant lot that each district of Edo had at its center and which was used partly as a dumpsite. However, dumping in these places had harmful effects, such as obstructing roads, waterways and firebreaks and bothering neighbors with bad odors, mosquitoes and flies.

In light of this unsatisfactory situation, the magistrate's

[Collection and transport in Edo]

Source: Yowatari Fuzoku Zue (Collected Genre Paintings of the World)