Taken from:
http://barebonesgardening.blogspot.com/2007/10/free-urea-based-fertilizer.html
Human urine makes an excellent high nitrogen liquid fertiliser for most plants. Dilute it 10 to 1 and pour it over and or round fast growing plants once a week; like vegetables, Green manure crops and sugar cane. Indeed just about anything that you want to push along rapid green growth
Studies indicate that each person’s waste fluids can provide enough nitrogen, phosphorous and potassium to grow a year’s supply of wheat and maize for that person. According to some studies, human waste can be an even more effective fertilizer than animal manure.
Urine, which comprises 90 percent of human waste, contains about 80 percent of our waste’s fertilizer value. It can be applied to field crops without treatment because it is generally sterile. By the way "fresh urine" does not contain any bacteria, unless the person has a urinary tract infection, so you could even use it to wash out wounds without causing any infections,
Human urine can be used as an alternative to chemical fertilizer to reduce pollution in air, water and soil and help avoid or control other environmental hazards which surface due to the use of chemical fertilizer, Human urine contains nitrogen, phosphorous and potassium at a much higher ratio than in commercial fertilizers and is environmentally safe to use.
If you want to use urine to fertilize your gardens, keep in mind that when urea becomes ammonia, it also becomes volatile and part of it strips into the air. Both ammonia and nitrates are also very soluble and if not picked up by plant's root systems can enter groundwater with the irrigation water. So it would be best to keep gardens moist but not over watered, but these are similar problems faced by people who use other forms of fertilizers.
Problems urine causes
Most toilets use between 50 and 100 litres of water daily to flush away one to 1.5 litres of human excrement.
Urine is the largest contributor of nutrients to waste water, estimated as 50% of phosphorus and 80% of nitrogen.
The high level of nutrients in sewerage runoff leads to the consequent growth of algae, resulting in the lack of oxygen and the death of plants and animals on river, estuarine and sea beds.
Problems Chemical Fertilizers cause
Serious environmental hazards are often associated with the use of chemical fertilizers. In industrialized countries, for example, indiscriminate use of these substances has polluted water supplies. Dangerously high levels of chemicals have been reported in nearly one-fourth of Europe’s groundwater supplies.
Advantages of Urine Fertilizer
One advantage in using urine, as a fertilizer is that much of the urine is available in ideal chemical forms: nitrogen is in the form of urea (ammonia/ammonium which is present at concentrations of approximately 3.5 g/l), phosphorus as superphosphate and potassium as an ion. Urine is almost free from heavy metals - for example, cadmium - because even if we ingest them, they will tend to bind to the liver and kidneys, making the urine much lower in such contaminants than commercial fertilizers.
Urea outside the body quickly becomes ammonia and will be oxidized by special bacteria (called nitrifiers) into nitrates. All these 'reactive' nitrogen sources can be used to form amino groups for new amino acids, thus then being made into proteins. So make other steps to encourage the soil life in your garden, eg things lie mulching etc.
It helps conserve pure or town drinking water
Reduces the rate and amount of chemical fertilizer runoff into the groundwater and surrounding waterways
Reduces the amount of sewerage runoff
Reduces nutrient build-up in waterways and estuaries and oceans
Reduces your gardening costs, because of less reliance on buying chemical fertilizers.
Uses
Probably best used for non-edible plants, green manure crops and fruit orchards, though there is some usage being noted for edible crops. Apply in under fruiting plants, not onto foliage and fruits.
In a Hydroponics set-up, use it diluted, probably at a ratio of either 10- 20 to 1(water- urine), but keep a close eye on both the ph level and the level of individual salts of the mix in the nutrient storage container.
Dilute urine is also a good additive to a compost pile. Urea also helps break down lignin, accelerating the decomposition of woody materials. On the other hand, urine from somebody with a urinary tract infection or from unknown sources should probably be pasteurised or put in a long-term compost pile (of a year or longer)before it is used on food crops.
When using a urine fertilizer in container plants, a 10:1 (water: urine) ratio can quickly burn plants in medium to small containers because of the salt and urea build-up, even at a 15:1 dilution rate is very strong for the medium to small containers. While at 20:1 you can use it more frequently (once or twice a week) with good benefits and little danger.
Unfermented urine can supposedly be sprayed as a fungicide. Indigenous people in southeastern Mexico claim that the use of urine as a fungicide was a traditional Mayan practice. However there needs to be a lot more research as to the validity or not of their claims.
While in Korea, they spray the undiluted urine as an insecticide, but again I do not know of any research to prove or disprove their claims.
So why not get out there, and help the environment by assisting in reducing the nutrient flow into the natural ground water and water ways, while saving yourself a bundle in fertilizer costs.
