IN the far reaches of Shaanxi Province in northern China, in an apple-producing village named Ganquanfang, I recently visited a house belonging to two cheery primary-school teachers, Zhang Min Shu and his wife, Wu Zhaoxian. Their house wasn’t exceptional — a spacious yard, several rooms — except for the bathroom. There, up a few steps on a tiled platform, sat a toilet unlike any I’d seen. Its pan was divided in two: solid waste went in the back, and the front compartment collected urine. The liquids and solids can, after a decent period of storage and composting, be applied to the fields as pathogen-free, expense-free fertilizer.

From being unsure of wanting a toilet near the house in the first place — which is why the bathroom is at the far end of their courtyard — the couple had become so delighted with it that they regretted not putting it next to the kitchen after all.

What does this have to do with you? Mr. Zhang and Ms. Wu’s weird toilet — known as a “urine diversion,” or NoMix (after a Swedish brand), toilet — may have things to teach us all.