When The Shit Hits The Field
SHTF has been a common name for a global disaster or cataclysm, but the reality is that in many parts of the world it is our own faeces that helps feed us.
Check out these snippets from an article in the South China Morning Post:
You produce some 500 litres of urine and 50kg of faeces a year. Besides water and organic carbon, your annual output contains about 10kg of nitrogen, phosphorus and potassium compounds, the three main nutrients plants need to grow – and, helpfully, in roughly the right proportions.
Scale that up and the world’s population excretes 70 million tonnes of nutrients annually. Applied to fields, this could replace almost 40 per cent of the 176 million tonnes of nutrients in chemical fertilisers used by the world’s farmers in 2011.
In India, despite laws banning the practice, an estimated one million people, mostly women and girls from lower castes, are still paid to scrape poo from the nation’s 100 million or more tanks and latrines, usually with nothing more than a shovel and bucket. They dump the contents in nearby drains or on waste ground. [Truly a waste].
“China’s use of night soil … is probably the reason that its soils are still healthy after four millennia of intensive agriculture,” wrote author Rose George, in a 2008 edition of Slate magazine; and since the 1890s, most of the sewage from Mexico City has been piped untreated to the fields of the Tula Valley, to the north. Today, that megacity’s 21 million people continue to fertilise more than 100,000 hectares with their faeces. The remains of the city’s digested beans, tortillas and chilli peppers double yields of corn and almost triple the rentable value of farms, says Blanca Jimenez, of the Mexican Academy of Sciences. In essence, poo has made Tula Valley farmers wealthy.
The biggest argument against agricultural recycling of sewage – whether from sewers or latrines and septic tanks – is that it carries disease. While urine is largely pathogen-free, faeces are rich in viruses, bacteria and worms. There are more than two million deaths a year worldwide from diarrhoea and other diseases associated with human waste. Most of these are down to poor hygiene, such as a lack of hand-washing, and are concentrated in areas where people still defecate in the open. Farming or eating crops fertilised by sewage is thought to play a minor role.
The big problem is that people in countries that don’t have proper sewers, tend to be the ones who lack basic hygiene. Illness from food grown in poop could be avoided by clever preppers:
- Always wash your hands and food thoroughly.
- Don’t grow salad vegetables in shit.
- If possible, mix in human waste with compost and bury it below the soil – the deeper the better, as long as roots can still reach it.
- Don’t forget to use animal poo, compost, seaweed, charcoal and other natural fertilizers as well.