Mick Hartley

Yes, an ambiguous heading. The Daily NK spells it out: "Every farming season, people are mobilized to dig manure from the bottom of 12 places — including ditches, swamps, toilets, pigsties and cow sheds — to spread on fields as fertilizer":

Last month, North Korea mobilized its people to participate in what it called the “Dig 12 Bottoms” campaign as part of efforts to make up for shortages of fertilizer. Many people in the country, however, are complaining that the method is yielding few results.

Speaking on condition of anonymity for security reasons, a reporting partner in South Pyongan Province told Daily NK on Tuesday that “the provincial party committee called for the Dig 12 Bottoms campaign to gather more alternative fertilizer based on the experiences and lessons of last year.” 

Suffering from fertilizer shortages, North Korea is increasing production of night soil and organic fertilizers to fill in the gap. Every farming season, the authorities mobilize people to conduct the Dig 12 Bottoms campaign, calling on them to dig soil from the bottom of 12 places — including ditches, swamps, toilets, pigsties and cow sheds — to spread on fields as fertilizer. 

The euphemistic "night soil" refers to human excrement. That's the, um, bottom line.

Many farmers are saying that while preparing manure is necessary for increasing agricultural production, they doubt whether mobilizing everyone for the Dig 12 Bottoms campaign will be effective, the reporting partner said. 

“People say providing more chemical fertilizers would be much more helpful in achieving the goal of increasing grain output by more than one ton per jeongbo [a Korean unit of measurement equal to approximately 9,900 square meters].”

More fertiliser would be nice, but the North Koreans seem incapable of producing any in sufficient quantity, or of sufficient quality. As a result, as I reported back in January, it's back to the old night soil and the "manure wars", where mass brawls break out as people struggle to meet the required shit quota.

This is not simply a matter of aesthetics: we avoid our own excrement for very good health reasons. There was the case of the soldier who escaped North Korea in November 2017 by running across the demilitarised zone. Badly wounded, he was rushed to hospital, where his intestines were found to be full of parasitic worms. The surgeon responsible said that he'd never seen anything like it before outside of textbooks. Other doctors have also described removing various types of worms and parasites from North Korean defectors. This, it's generally believed, is a direct result of using human excrement as fertiliser.