•How farmers can utilise human urine as eco-friendly fertiliser for crops
As fertiliser prices continue to soar and food insecurity deepens in Nigeria, especially among small-scale farmers, the search for sustainable, low-cost alternatives has never been more urgent. One unlikely solution gaining traction is human urine, a rich, readily available source of nitrogen and phosphorus. SADE OGUNTOLA explores the usefulness of this eco-friendly fertiliser and how it can boost crop yields, restore soil health, and reduce dependency on expensive chemical inputs.
WHEN Professor Olugbenga Adeoluwa, a professor of soil fertility at the University of Ibadan, and his family moved to the staff quarters of the campus in 2007, he needed to grow food organically that his family could depend on when needed.
As such, the expansive land behind his quarters proved to be beneficial for that purpose.
While many farmers apply fertiliser to boost the quality and growth of the crops and prevent said crops from diseases, Prof Adeoluwa successfully grew a variety of vegetables and other crops organically for his family’s consumption, utilising urine as a fertiliser.
“When we moved to the University of Ibadan campus in 2007, the area of land behind the quarters was barren. I needed to grow my food organically. So, we began collecting our urine,” Professor Adeoluwa explained.
Checks by Sunday Tribune showed that farmers have always turned to fertilisers in different forms to restore degraded soils and to help increase food production quickly.
Depending on the specific conditions of the soil and crops, the types of fertilisers available to farmers include nitrogen-based fertilisers such as urea, ammonium nitrate, ammonium sulfate; phosphorus-based fertilisers such as single superphosphate (SSP), triple superphosphate (TSP), diammonium phosphate (DAP); potassium-based fertilisers such as muriate of potash (potassium chloride), sulfate of potash; compound/blended fertilisers (NPK) such as 15-15-15, 20-10-10 and organic fertilisers such as compost, manure, green manure (e.g., legumes). Some farmers even pick the worst options by applying pesticides to the crops before they are taken to the market for sale.
But the agronomist and National Coordinator of the Organic and Agroecology Initiative in Nigeria (ORIG) chose organic fertiliser because he has always conducted experiments using urine as a fertiliser on various crops.
To do this, the Adeoluwa’s family collects their urine in an airtight container and stores it at a cool room temperature for three months. Under these conditions, the composition of the urine transforms from an acidic to an alkaline state, resulting in a highly saline product that is odourless and is free of germs.
“This way, it provides nutrients that are easier for plants to easily take up. So we have no reason to buy chemical fertiliser to restore the degraded land behind us. However, we do use additional materials,” he explained.
Checks showed that fresh urine is composed of 95 per cent water, with 2.5 per cent consisting of urea and an additional 2.5 per cent comprising a mixture of minerals, salts, hormones, and enzymes. This composition makes urine a readily available source of nutrients for plant growth.
Urine’s effectiveness as a fertiliser is attributed to the nitrogen and phosphorus it contains—nutrients that are also found in the synthetic fertilisers commonly used on many conventional farms. However, the use of these synthetic fertilisers carries an environmental cost.
Different crops and plants have varying nutritional requirements. Historical records indicate that urine was utilised to promote crop growth in ancient China and Rome; however, its use declined with the advent of modern sewage systems and chemical fertilisers.
Today, scientists are discovering that urine fertiliser can more than double the yield of crops such as kale and spinach compared to the absence of fertiliser, and it can also enhance yields in low-fertility soils.
In Niger State, it is taboo for some women to speak of urine, so a research project among women farmers renamed it oga, which means “boss” in Igbo. In a paper published in the journal Agronomy for Sustainable Development, when the farmers applied home-produced oga fertiliser to pearl millet every two weeks, yields rose by 30 per cent.
Oga has since become a regionally popular fertiliser because it works well, costs very little, and is socially acceptable. The women were relieved of the rising commercial fertiliser costs and the scarcity of animal manure.
While the use of urine and human faeces as fertilisers varies for different crops, the World Health Organisation’s guidelines stipulated that the storage period for urine can range from one to six months, depending on the type of crop.
On safety concerns, Professor Adeoluwa assured that the use of urine is safe and that all crops can benefit from urine as a fertiliser if the appropriate standards are followed.
He, however, stated that urine should be applied in its diluted form using a conventional sprayer, as concentrated urine can harm the plants. It can also be added regularly to the irrigation water; however, this should not be done during intense sunshine, strong winds, rain, or in very saturated soils. Even so, the frequency of urine application depends on the specific plants being watered. Different crops and plants have varying nutritional needs. Some can be fertilised as frequently as once a week, while others may only require fertilisation two or three times.
In addition, he stated that the large-scale use of urine-based fertiliser has no environmental implications. Furthermore, due to the dilution with water and the ageing process of the urine, it does not emit any odour.
He also noted that fresh human urine is sterile and free from bacteria. It is only after 24 hours that urea begins to decompose into ammonia, which is responsible for the characteristic odour of urine.
Will such foods be edible?
One potential issue is that individuals may be hesitant to consume food grown with urine-based fertilisers. Many people may not realise that these fertilisers undergo treatment processes that ensure they are safe and will not cause illness.
“When we began the research, the produce was brought to the university for sale. The items were labelled according to their treatment. A portion was designated for distribution, while another was intended for sale. Even after people learned that it was grown using a urine-based fertiliser, they still purchased it,” he declared.
Researchers have demonstrated that stored human urine is unlikely to spread antimicrobial resistance. In an article published in the Journal of Environmental Science and Technology, they stated that if urine is aged—as is typical in most systems designed for urine collection for fertiliser—it is improbable that it will contribute to the spread of antibiotic resistance when applied to crops.
The team collected over 100 litres of urine from both male and female donors across Vermont and stored it for a period of 12 to 16 months—sufficient time for a substance in the urine, known as urea, to decompose into ammonia.
Moreover, urine can be utilised to enhance nitrogen-deficient compost.
Dr Florence Olowookere, a soil fertility and crop nutrition expert at the Department of Soil Science and Land Management at the Federal University of Agriculture, Abeokuta, who has researched cow urine, asserted that moistening the compost with cow urine can improve the quality of the crops produced.
The quality of produce from cow urine-moistened compost is superior to that from water-moistened compost. Urine serves as an excellent compost accelerator and activator, providing the additional benefit of enhancing nutrient content.
The compost was created using poultry manure and rice husks. The cow urine was stored in an airtight container for approximately three weeks.
“We observed improvements in several properties, such as nitrogen, phosphorus, and potassium uptake in the soil. Additionally, the protein and crude fibre content of our crop, amaranth, were significantly higher than those of the control group,” she declared.
Dr Olowookere, however, stated that obtaining sufficient cow urine for use is challenging, as cows typically roam freely and may urinate and defecate in the same area.
According to her, “You cannot rule out the possibility of urine mixing with the faeces you are collecting. It’s different from when you place, for example, a bowl under the cattle to collect their urine. In that case, you can be certain that you are only collecting urine.”
Moreover, the chairman of the All Farmers Association of Nigeria, Oyo State chapter, Mr. Adewunmi Abass Adekunle, stated that farmers who combine rabbit urine with their droppings can enhance crop production.
According to him, “Farmers who plant pepper, rodo (Scotch Bonnet or Habanero pepper), and leafy vegetables report that rabbit urine helps boost yield. They do not use chemical fertilisers, as these are scarce and expensive. The only issue we face is the availability of rabbit urine.”
Also speaking with the Sunday Tribune, Pastor Okugbo Babajide, who rears rabbits, stated that members of the Oyo State Rabbit Breeders Association profit from the sale of rabbit urine and droppings.
The diluted urine of rabbits is regularly sprayed on the leaves of plants to prevent insects from destroying them. Additionally, the dung is sold to farmers, including those from Eruwa and Oke Ogun, for use in nourishing their crops.
“Some of us practice integrated farming, so whatever manure is produced from the animal farm is taken to the vegetable farm for use as fertiliser,” he added.
He also claimed that he has used rabbit urine as a fertiliser for planting plantains, cucumbers, watermelons, and corn.
A significant blow to greenhouse gases
Human urine is one of the major domestic wastes generated daily, yet it is often poorly managed in many developing countries, particularly in urban areas with high populations.
According to Dr Olufemi Ayanfeoluwa, a lecturer at the Federal College of Agriculture in Ibadan, human urine has the potential to enhance food production in Nigeria by increasing both the yield and quality of various crops.
He stated, “If embraced, it will reduce the need for synthetic fertilisers, thereby decreasing greenhouse gas emissions associated with synthetic fertiliser production and lowering the carbon footprint, thus mitigating the effects of climate change.
“Its performance is comparable to that of mineral fertilisers and, in some reports, even superior. Like other organic fertilisers, crops grown with human urine also demonstrated improved quality in terms of nutrition and shelf life.”
Ayanfeoluwa, who has researched the use of urine as a biofertiliser, stated that human urine is one of the primary domestic wastes generated daily. Unfortunately, it is often poorly managed in many developing countries, particularly in urban areas with high population densities.
He stated that human urine could be utilised as a standalone fertiliser or in conjunction with other types of fertilisers, depending on the composition of each batch and the limiting nutrients present in the soil. Additionally, he said it can be applied alone before planting or in split applications when necessary.
Professor Julius Olasoji of the Maize Improvement Programme at the Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan, expressed concern regarding farmers’ access to sufficient urine as an alternative fertiliser.
He highlighted cultural perceptions that regard urine as unclean, as well as challenges related to its collection and safety. According to Professor Olasoji, having a consistent source of urine is essential.
“If you’re referring to urine from rabbits, how many rabbits are there in this entire country? Our herds of cows are free-range, and standard toilets do not separate human urine from faeces at the source. Even if they did, there is no system in place for its collection. That is the challenge.
“In applied science, the questions we need to consider are: Is it available? Is it accessible? Is it affordable? These questions must be addressed to ensure its easy adoption in the field later on.”
In recent years, excessive farming practices and climate change have led to the depletion of soil nutrients in Ekwusigo LGA. Many subsistence farmers in the area cannot afford fertilisers, resulting in very poor crop yields.
To support farmers, particularly women, in tackling low agricultural yields caused by continuous cultivation, a non-governmental organisation, Life Giver Foundation, introduced farmers in the area to the use of urine as an alternative to traditional fertilisers.
Executive Director of the Life Giver Foundation, Reverend Sister Stella Ewa, who announced the unveiling of a new project supported by the Arise Foundation, a United States-based NGO, said this initiative aims to enhance soil fertility by introducing an effective, cost-friendly, and easy-to-use fertiliser designed to increase agricultural yields, boost household income, and provide nutritious food.
Amidst the challenging fertiliser supply and soaring prices caused by a severe shortage of foreign exchange for imports, the utilisation of organic alternatives, such as human urine as a fertiliser for crop production, will undoubtedly support increased food production.
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