Washington, D.C.-Human urine mixed with wood ash has been found to produce bumper crops of tomatoes without causing a risk of disease for consumers. This, according to the first study evaluating the combination as a fertilizer for food crops, is soon to be published in the American Chemical Society’s bi-weekly Journal of Agricultural and Food Chemistry. The author, Surendra Pradhan, points out that urine is a good source of nitrogen and has been successfully used to fertilize cucumber, corn, cabbage, and other crops. However, Pradhan reports, only a few studies have investigated the use of wood ash, which is rich in minerals and also reduces the acidity of certain soils, and none have published to date. The new study found that plants fertilized with urine produced four times more tomatoes than non-fertilized plants, and equally as much as plants given synthetic fertilizer. Urine plus wood ash produced almost as great a yield, with the added benefit of reducing soil acidity. “The results suggest that urine with or without wood ash can be used as a substitute for mineral fertilizer to increase the yields of tomato without posing any microbial or chemical risks,” the report says.
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