Washington, September 19 A new study has proven that human urine mixed with wood ash can be a natural fertilizer.

According to a report in National Geographic News, the study was carried out by Surendra Pradhan, an environmental scientist at University of Kuopio in Finland.

In many ways, the substances are natural complements, explained Pradhan.

Urine is high in nitrogen, while wood ash is rich in nutrients not found in urine, such as calcium and magnesium.

Human urine and wood ash have each separately been used as fertilizer for centuries. But until now, no one had explored applying them together.

For the research, Pradhan and his team fertilized several groups of greenhouse tomato plants: one with human urine and birch ash, another with commercial mineral fertilizer, and another with just urine.

Plants fertilized with urine and ash yielded nearly four times more tomatoes than nonfertilized plants.

This compared favorably with commercial mineral fertilizers, which produced roughly five times as much fruit as nonfertilized plants.

To the team's surprise, urine alone produced a slightly greater yield than those of urine and ash together.

But the urine-and-ash plants became larger than the other groups, and they bore tomatoes with significantly higher levels of the nutrient magnesium, which is key for bone, muscle, and heart health, among other biochemical functions.

A group of 20 taste testers ranked tomatoes grown by all methods as equally tasty.

The best part of this type of fertilization is that "it is a very simple process," Pradhan said.

The researchers estimate a single person could supply enough urine to fertilize roughly 6,300 tomato plants a year-yielding some 2.4 tons of tomatoes.

The farmer would just need to give plants ash three days or more after applying urine.

Pradhan and his colleagues are now trying to implement this idea in Nepal. (ANI)