Researchers say our liquid waste not only promotes plant growth as well as industrial mineral fertilizers, but also would save energy used on sewage treatment.
"It is totally possible to use human urine as a fertilizer instead of industrial fertilizer," says Heinonen-Tanski, whose research group has also used urine to cultivate cucumbers, cabbage and tomatoes. Recycling urine as fertilizer could not only make agriculture and wastewater treatment more sustainable in industrialized countries, the researchers say, but also bolster food production and improve sanitation in developing countries.
Stored Human Urine Supplemented with Wood Ash as Fertilizer in Tomato (Solanum lycopersicum) Cultivation and Its Impacts on Fruit Yield and Quality
This study evaluates the use of human urine and wood ash as fertilizers for tomato cultivation in a greenhouse. Tomatoes were cultivated in pots and treated with 135 kg of N/ha applied as mineral fertilizer, urine + ash, urine only, and control (no fertilization). The urine fertilized plants produced equal amounts of tomato fruits as mineral fertilized plants and 4.2 times more fruits than nonfertilized plants. The levels of lycopene were similar in tomato fruits from all fertilization treatments, but the amount of soluble sugars was lower and Cl− was higher in urine + ash fertilized tomato fruits. The β-carotene content was greater and the NO3− content was lower in urine fertilized tomato fruits. No enteric indicator microorganisms were detected in any tomato fruits. The results suggest that urine with/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.
From Wikipedia the Free Enciclopedia;
Main article: Fertilizer
Urine contains large quantities of nitrogen (mostly as urea), as well as significant quantities of dissolved phosphates and potassium, the main macronutrients required by plants, with urine having plant macronutrient percentages (i.e. NPK) of approximately 11-1-2 by one study or 15-1-2 by another report, illustrating that exact composition varies with diet. Undiluted, it can chemically burn the roots of some plants, but it can be used safely as a source of complementary nitrogen in carbon-rich compost.
When diluted with water (at a 1:5 ratio for container-grown annual crops with fresh growing medium each season, or a 1:8 ratio for more general use), it can be applied directly to soil as a fertilizer. The fertilization effect of urine has been found to be comparable to that of commercial fertilizers with an equivalent NPK rating. Urine contains most (94% according to Wolgast) of the NPK nutrients excreted by the human body. Conversely, concentrations of heavy metals such as lead, mercury, and cadmium, commonly found in solid human waste, are much lower in urine (though not low enough to qualify for use in organic agriculture under current EU rules). The more general limitations to using urine as fertilizer then depend mainly on the potential for buildup of excess nitrogen (due to the high ratio of that macronutrient), and inorganic salts such as sodium chloride, which are also part of the wastes excreted by the renal system. The degree to which these factors impact the effectiveness depends on the term of use, salinity tolerance of the plant, soil composition, addition of other fertilizing compounds, and quantity of rainfall or other irrigation.
Urine typically contains 70% of the nitrogen and more than half the phosphorus and potassium found in urban waste water flows, while making up less than 1% of the overall volume. Thus far, source separation, or urine diversion and on-site treatment has been implemented in South Africa, China, and Sweden among other countries with the Bill and Melinda Gates Foundation provided some of the funding implemenations. China – in 2003 reportedly had 685,000 operating source separation toilets spread out among 17 provinces 
"Urine management" is a relatively new way to view it and close the cycle of agricultural nutrient flows, to reduce sewage treatment costs, reduce ecological consequences such as eutrophication, and reduce the influx of nutrient rich effluent into aquatic or marine ecosystems. Proponents of urine as a natural source of agricultural fertilizer claim the risks to be negligible or acceptable. Their views seem to be backed by research showing there are more environmental problems when it is treated and disposed of compared with when it is used as a resource.
It is unclear whether source separation, urine diversion, and on-site treatment of urine can be made cost effective, and to what degree the required behavioral changes would be regarded as socially acceptable, as the largely successful trials performed in Sweden may not readily generalize to other industrialized societies. In developing countries, the application of pure urine to crops is rare, but the use of whole raw sewage (termed night soil) has been common throughout history. However, there are more calls for urine's use as a fertilizer such as a Scientific American article "Human urine is an effective fertilizer".
Quote From the Energetic Forum;
What’s in urine?
Urine, 95% of which is water, 2.5% of which is urea, and 2.5% of which is a mixture of minerals, salts, hormones, and enzymes, is not a toxic waste product. Urine is a blood byproduct and though it contains some body waste, it is non-toxic. In 1975, Dr. A.H. Free, published his book Urinalysis in Clinical Laboratory Practice, in which he presents a few critical nutrients found in urine:
Alanine, total ..... 38 mg/day
Arginine, total ..... 32 mg/day
Ascorbic acid ..... 30 mg/day
Allantoin ..... 12 mg/day
Amino acids, total ..... 2.1 g/day
Bicarbonate ..... 140 mg/day
Biotin ..... 35 mg/day
Calcium ..... 23 mg/day
Creatinine ..... 1.4 mg/day
Cystine ..... 120 mg/day
Dopamine ..... 0.40 mg/day
Epinephrine ..... 0.01 mg/day
Folic acid ..... 4 mg/day
Glucose ..... 100 mg/day
Glutamic acid ..... 308 mg/day
Glycine ..... 455 mg/day
Inositol ..... 14 mg/day
Iodine ..... 0.25 mg/day
Iron ..... 0.5 mg/day
Lysine, total ..... 56 mg/day
Magnesium ..... 100 mg/day
Manganese ..... 0.5 mg/day
Methionine, total ..... 10 mg/day
Nitrogen, total ..... 15 g/day
Ornithine ..... 10 mg/day
Pantothenic acid ..... 3 mg/day
Phenylalanine ..... 21 mg/day
Phosphorus, organic .....9 mg/day
Potassium ..... 2.5 mg/day
Proteins, total ..... 5 mg/day
Riboflavin ..... 0.9 mg/day
Tryptophan, total ..... 28 mg/day
Tyrosine, total ..... 50 mg/day
Urea ..... 24.5 mg/day
Vitamin B6 ..... 100 mg/day
Vitamin B12 ..... 0.03 mg/day
Zinc ..... 1.4 mg/day
(Your Own Perfect Medicine? - Natural Health and Longevity Resource Center)
The following are the average quantities of various substances, in 100 milliliters of urine as reported in Introduction to Biochemistry by Dr. Pharon:
1] Urea nitrogen 682.00
2] Urea 1459.00
3] Creatinin nitrogen 36.00
4] Creatinin 97.20
5] Uric acid nitrogen 12.30
6] Uric acid 36.90
7] Amino nitrogen 9.70
8] Ammonia nitrogen 57.00
9] Sodium 212.00
10] Potassium 137.00
11] Calcium 19.50
12] Magnesium 11.30
13] Chloride 314.00
14] Total sulphate 91.00
15] Inorganic sulphate 83.00
16] Inorganic phosphate 127.00
17] N/10 acid 27.80
Some other important urine constituents are:
Lactic dehydrogenate (L. D. H.).
Leucine amino-peptidase (L. A. P.).
Is there a difference between male and female urine? Read HEREFurther reading; Stocholm Environment Institute