A recent study has shown that the growth and biomass of the plants were slightly higher with urine than with conventional fertilizer (human urine was collected from private homes and used it to fertilize cabbage crops). I am not really surprised with the findings, because it is indeed true that urine from healthy individuals is virtually sterile and free of bacteria or viruses. Urine contains large amounts of urea which is an excellent source of nitrogen for plants. In fact due to the presence of nitrogen, phosphorus and potassium it is widely considered to be as good as or even better than commercially-available chemical fertilizers. Human urine is widely used for composting. It is often recommend by gardeners to dilute 10-20 parts water to one of urine for application to pot plants and flower beds during the growing season, this is mainly because undiluted urine can chemically burn the roots of some species. So, you can’t just go and pee on your plants! In spite of the ‘yuk’ factor, it is indeed a great idea to use diluted urine for your plants, because it is not only inexpensive (free if it is from your very own household), but it great for the plants and the soil too. Source
