Most of us don’t like to think about it too much, but you probably know that animal poo is used as fertiliser to grow the crops that we eat.

But how would you feel if your parsnips were produced using human poop? That’s the question that researchers put to people in England and Japan for a study in the Waste Management Bulletin.

They were asking because human fertiliser could make farming more sustainable, as animal fertilisers can pollute water and the atmosphere, while man-made fertilisers need fossil fuels and a lot of energy.

Human poop is known as ‘night soil’ when it’s used as fertiliser. Many countries have been using it for hundreds of years although, if it isn’t treated properly first, it can have some health risks, such as spreading bacteria.

However, modern methods mean that these risks aren’t as big a problem to deal with.