Human urine as fertiliser can save farmers

Saturday January 11 2020

Barigye demonstrating the preservative in the

Barigye demonstrating the preservative in the urine. Photo by Charlotte Ninsiima. 

By Charlotte Ninsiima

Julius Ayebare has been using human urine for the last two years on his one-acre farm in Hamurandi village, Bubaare Sub-County in Rubanda District.
He collects 40 litres every month from his family members. After attending numerous trainings at Kabanyoro Demonstration Farm, he gained insight on the use of urine as a natural fertiliser.

“I opted for human urine because I did not want to produce chemically flavoured foods since we spray using chemical fertilisers. For instance, if I use chemical fertilisers on passion fruits, during the harvest, I have to first wash them before I take them to the market, which is cumbersome. So I resorted to urine to produce fresh organic food. I have witnessed positive results including increased size of the cabbages and more fertile soil,” Ayebare narrates.

He farms cabbage, passion fruits and potatoes.
Moses Barigye, Director Mbale community, Africa Science Graduates Organisation (ASGO) says, every plant’s major food component is phosphorous.
The soil acts as a bucket which holds the plant. When the soil dries up from nutrients and the plant will dry, he says.

Human urine is a resource for production and fertiliser, which isprocessed before it is applied in the farms.
Barigye advises that for one to increase the production of urine, production must be enhanced by increasing intake of drinks. At subsequent times, one releases half a litre of urine.

Humans have first class waste matter because it is a resource from combined flora and fauna species.
ASGO is trying to reinstate the fertility of the soil so that the plants produced can acquire the required nutrients for human consumption. The urine project under ASGO collects urine from the public to be used as a fertiliser on large scale farming.

Urine composition
Samuel Kamya, a plant scientist at KessBiosciences, cites urine as an alternative fertiliser for NPK. Urine’s composition includes nitrogen occurring as ammonium or urea, phosphorus occurring in an inorganic form and potassium. The approximate concentration ratios of NPK in urine are 20:1:4 which is comparable to commercial chemical fertiliser.
Kamya adds, other elements in urine include chloride, sodium, magnesium and copper. Some organic and inorganic compounds may occur in urine and these depend on how it’s harvested.


Urine contains more nutrients than feces, grey-water and biodegradable suspended solids. All of these nutrients occur in a soluble state.
Pros of urine
In terms of performance, there is no difference between urine and chemical fertilisers of NPK blend. Urine has the advantage of being easily accessible to anyone who wishes to use it. Kamya explains, on average an adult passes out 1.4 litres of urine daily.

Environmentally, urine plays well into a circular economy where nitrogen is consumed by bean plants instead of it ending up in sewers and finally lakes where it is contributing to eutrophication (the process by which a body of water becomes enriched in dissolved nutrients (such as phosphates) that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen) or the so called algal-blooms, Kamya explains.

“It can be applied to all plants at any stage but it must first be stored away for at least three weeks. During this time, the urea and proteins break down further to ammonia. During this time, it also self sterilises. Hence, it is void of viruses or bacteria like salmonella after storage. Those interested in purely organic farming, urine is a good source of nitrogen for plant growth.”

“Compared with animal manure and industrial fertilisers, the heavy metal concentrations of urine are lower. So urine is very safe, he adds.

Barigye says urine is rated depending on the highest priced element it contains. In each litre, there is 0.15gms of phosphorous which costs Shs32,000, on the global market.

“When one eats food, it is quantity but when you bring out the human waste, which is scientifically termed as resources, you bring quality. In science, when you eat Shs100,000, within 24 -hour period, you bring out a value multiplied thrice.”

“Only registered members of ASGO are given containers with a concentrator to preserve the urine so as to maintain its properties. As the day passes, urine changes the properties; change of smell and colour,” Barigye admits.

Milton Mugweri, a father of seven, in Bukasa village, Bweyogerere, Wakiso District delivers a minimum of five litres of urine daily from his household.
“I have been enlightened about the importance of the urine, which we neglected earlier on. At least I am assured of food supply in the next eight months since I give them urine.”

“In every household, 75 per cent expenditure is spent on food production. If expenses on food are cancelled, other developments can sprout. For scientists we believe that every person that is hungry, is hopeless, therefore, food is economic welfare.”
Barigye urges farmers to register with ASGO to meet the challenge of inadequate supply. The members are subsequently trained on preservation and how to urinate.

Barigye advises that qualified personnel need to handle urine.
Kamya cautions against using human urine as the only fertiliser since it runs the risk of accumulating sodium salt in the soil.

“This accumulation is more than responsible for the burning effect observed with urine usage. However, a good application of either charcoal dust or manure should somehow offset this problem due to its advantage of binding the ammonia instead of it escaping to the atmosphere.”

When to apply
Kamya advises that application of urine after germination has no impact on seedlings.
ASGO has 98,000 producers of urine in 78 districts in Uganda.

“We shall give each member food for free after its production in six months’ time,”he said.
ASGO aims at replacing artificial with organic ones which they say are essential for crop production.

Human urine is one of the fastest-acting, most excellent sources of nitrogen, phosphorous, potassium and trace elements for plants, delivered in a form that’s perfect for assimilation. Dilute in 30-50 parts water for use on pot plants, which are much more sensitive to fertilisers of any kind.

Using urine instead of disposing of it also cuts down on river pollution: urine is a major source of nitrogen, which, if an expensive denitrification process is not undertaken at the water treatment plant, can contribute to river eutrophication. Excessive levels of nutrients in our effluent systems leads to the growth of algae.