Human urine can help grow bumper tomato crops

Human urine can help grow bumper tomato crops that can be eaten safely, says a new study.
Surendra Pradhan, an environmental biology researcher at the University of Kuopio, Finland, and colleagues gave potted tomato plants one of three treatments: mineral fertilizer, urine and wood ash, or urine only. Yields for plants fertilized with urine, rich in nitrogen, phosphorus and potassium, quadrupled and matched those of mineral-fertilized plants. The urine-fertilized tomatoes also contained more protein and were safe for human consumption.
"This is a very simple technology. Urine can be collected in a urine-diverting toilet or it can be collected in a separate jerry can [from] an ordinary, pre-existing toilet," said Pradhan.
"If wood ash is available, this can be use as a supplement of phosphorus, potassium and other nutrients," Pradhan added.
He says that the method is a free alternative to expensive mineral fertilizer, which is not easily available in remote or hilly areas.
A pilot programme based on the research will be launched in Nepal in November, says Pradhan, who is of Nepalese origin.
But Hn. J on, eco-agriculture and sanitation system technology expert at the Stockholm Environment Institute in Sweden says, "the amount [of urine] that can be collected from a person or a family is fairly small".
"[The technique] is of great value to a subsistence farmer but does not suffice for even a medium-scale cash-crop farm," said J?on.
He adds that to fertilize larger areas, many urine-diverting toilets would have to be linked up to a good transportation system.
Their research was published in the Journal of Agricultural and Food Chemistry.