The household nutrient cycle

Growing plants on the balcony? I do, and tomatoes need lots of fertile soil. Worms make fertile soil for free. In my bicycle shed (typically Dutch I suppose). While in Iowa last year, I was inspired by the ‘urban ag movement’ and I saw an instruction on the cityfarmer website which led me, on return, to close my household nutrient cycle better by composting my own vegetable food scrapes. It took a while to get the right balance in the three-story box that we build out of plastic storage boxes but it is working well now. The worm castings are extremely fertile as is the liquid (their pee and the muck water from the food scrapes). And it is fun, I think, to compost and close part of the cycle in this way.

Back in the 19th century, Marx was worried about disrupted nutrient cycles since large amounts of nutrients were traveling to city and town while none of that returned to the field. During 1830 – 1870 the depletion of the soil fertility was the overriding environmental concern in Europe and the US. Prior to the discovery of chemical fertilizers, bone and Peruvian guano (accumulated dung of sea birds) were massively imported in Britain to relieve soil exhaustion while other countries had to search for alternatives because of the British monopoly on guano (Foster 1999).

“The second agricultural revolution, associated with the application of scientific chemistry to agriculture, was therefore at the same time a period of intense contradictions” Foster (1999:377) writes. The discoveries in soil sciences also made farmers even more acutely aware of the depletion of the soil and the need for fertilizers. Marx understood that soil fertility is “not so natural a quality as might be thought; it is closely bound up with the social relations of the time” (Marx in Foster 1999; 375) captured in his concept of metabolism. His writings about metabolism can be seen as one of the earliest writings on what is now called ‘sustainability’.

City and waste

We are very familiar with recycling paper, glass and recently, plastic. It feels good that this waste is turned into a resource again. Many of us are also recycling food scrapes through municipal services, backyard compost heaps or small-scalle vermiculture.  However,when we are flushing the toilet, we do not often see our own waste as a valuable resource.

Our sewage system seems the only and logical answer nowadays but it was highly debated in the 19th century for its disadvantages before it was adopted (like pasteurisation was rejected by medical doctors  because it would also kill all the ‘good’ in milk, see Dupuis 2005). Alternatives were cesspools or the barrel system. Cesspools and sewage pipes were believed to leak and thus to contaminate the groundwater. Contaminated groundwater due to the absence of city-wide waste disposal systems was, by then, seen as the primary cause for outbreaks of cholera and typhus in the mid 19th century.

barrel cart Groningen

The Netherlands had a vocal protagonist of the barrel system in the medical doctor Ali Cohen from Groningen (Houwaart 1997). He became nationally known for his zeal for urban waste disposal. The barrel system simply meant that human waste was collected in barrels which were emptied in a cart behind horses. The waste was then turned into compost at a city composting place after which the compost was sold to the farmers outside the city. Cohen strongly believed in the composting of human faeces as a fine example of restored balance between man and nature, city and countryside.

Various Dutch cities tried the barrel system. However, it turned out not to be profitable, except in the city of Groningen. The special conditions in north of the Netherlands, including the existence of good waterways and large farm holdings in the immediate area were lacking in other parts of the country ( Houwaart 1997). While other cities started investing in sewage systems, the barrel system continued in Groningen until the beginning of the 20th century. Not a very clean practice, emptying barrels in the middle of the street. But the city government always refused to improve the system despite new ideas such as not emptying it on the spot but changing the barrel for a cleaned and disinfected one.  The result was that at the end of the 19th century the city was, totally unlike Cohen’s ideals, stuck with a very outdated waste disposal system compared the other Dutch cities.