AgricultureMain 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[SUP]
[18][/SUP] or 15-1-2 by another report,[SUP]
[19][/SUP] 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.[SUP]
[20][/SUP]
When diluted with water (at a 1:5 ratio for container-grown
annual crops with fresh growing medium each season,[SUP]
[21][/SUP] or a 1:8 ratio for more general use[SUP]
[20][/SUP]), 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.[SUP]
[22][/SUP] Urine contains most (94% according to Wolgast[SUP]
[18][/SUP]) 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).[SUP]
[23][/SUP] 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),[SUP]
[21][/SUP] 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.[SUP]
[24][/SUP]
China reportedly had 685,000 operating source separation toilets spread out among 17 provinces in 2003.[SUP]
[25][/SUP]
"Urine management" is a relatively new way to view closing the cycle of agricultural nutrient flows and reducing sewage treatment costs and ecological consequences such as
eutrophication resulting from the influx of nutrient rich effluent into aquatic or marine ecosystems.[SUP]
[19][/SUP] 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.[SUP]
[26][/SUP]
It is unclear whether source separation,
urine diversion, and on-site urine treatment can be made cost effective; nor whether 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.[SUP]
[22][/SUP] In developing countries the use of whole raw sewage (
night soil) has been common throughout history, yet the application of pure urine to crops is rare. Increasingly there are calls for urine's use as a fertilizer, such as a
Scientific American article "Human urine is an effective fertilizer".[SUP]
[27][/SUP]
just dont overdo it, or the salts/minerals will build up and ruin your soil.
after all, composted manure is animal shit and piss.
fuck you.