Last weekend, I found myself defending some of my favorite farmers for their use of chemical fertilizers. My argument was some paraphrasing of what they had told me: Without chemical fertilizers, it is nearly impossible to get enough nitrogen in the soil to keep stuff growing, unless you slow things way down and strategically plant legumes. Realizing these farms are barely making ends meet (especially this year after it rained all June), my argument continued, it is the big farms that can take more risks and find ways around petroleum-soaked fertilizers — hopefully to the eventual benefit of all farmers.
I wish I had seen this new study before I got on my soapbox. Apparently tons of available nitrogen can be found in, er, human pee. Mix it with wood ash and it becomes a powerful fertilizer. (Together they provide high amounts of nitrogen, phosphorus and potassium, calcium and magnesium.) Talk about interdependence!
The urine/ash fertilizer significantly increased crop yield “without posing any microbial or chemical risks,” reports the Journal of Agricultural and Food Chemistry. Furthermore, levels of the vitamin beta carotene were higher when the urine/ash fertilizer was used in comparison to other fertilizers.
In all fairness, plants treated with the mineral fertilizer did have, on average, two more fruits per plant than plants given the natural fertilizer. But urine still tripled the yield obtained with no fertilizer.
This particular study focused on tomatoes, but urine has also been successfully used to fertilize cucumber, corn, cabbage and wheat and is likely to be more widely applicable.
Now, dancing in my head, I have a relentless sci-fi fantasy of trading eco-toilet gatherings for produce at the greenmarket. What an image to start the day.
photo by Nikhil Gangavane via Dreamstime