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BY RICHARD DRASIMAKU
KAMPALA: TUESDAY, OCTOBER 29, 2024
At a slummy suburb of Uganda’s Capital City, Kampala, Dr Charles Niwagaba, an associate professor of civil engineering at Makerere university is spearheading research basing on human urine as a source for cheap fertilizer.
It is hoped that this could bring a fundamental turnaround in small holder agriculture commercialization and household wealth creation.
It is still work in progress, said, Dr Niwagaba, but the results are already promising with registered increment in yields from experimental plots using maize as test crop.
A successful conclusion of the research and adoption of the recommendations could change the way the Ugandan community handles resource recovery such as human waste and utilize it for furthering agricultural productivity.
Any breakthroughs would also be applied to promote sanitation and agriculture production in the refugee camps where millions of displaced people from South Sudan, Democratic Republic of Congo and Rwanda are settled in parts of West Nile, Northern Uganda, Central and Western Uganda.
Why maize was selected
Dr Niwagaba says the choice of maize as a test crop was based on the fact that maize has increasingly become a major non-traditional export cash crop particularly benefiting smallholder farmers and yet the crop is a heavy feeder in terms of fertilizer and water intake.
Maize is the most important cereal crop grown in Uganda providing up to 40% of the calorie needs according to the National Agricultural Advisory Services (NAADS).
The crop has increasingly become a staple food in many parts of the country, especially among the small-scale farmers who constitute the bulk (80%) of the rural poor.
These also account for the largest share of maize production which is grown in every part of Uganda and is a direct source of livelihood to over two million households, over 1,000 traders/merchants and over 600 millers.
However, a comparative study by Africa Agriculture Watch found fluctuation in maize production levels in key producer districts reflecting steep drop of for instance 43 percentage points in Iganga between 2015 an 2024.
Land degradation and fertility reduction which could be mitigated through fertilizer use was cited as one of the reasons alongside the vagaries of weather, for this negative trend.
AAgWa, a project of AKADEMIYA2063 uses artificial intelligence-based model known as Africa Crop Production Model, to forecast crop production at the beginning of every season.
This information is thought to be vital especially to those involved in the agriculture value chain to better plan and execute policies and business actions.
Farmer’s reaction
Emmanuel Ajedra, a prominent farmer in Arua says plants are green because of nitrogen and the energy giving nutrient is a major component in urine.
He explains that in zero grazing housing for the animals whether goats, cattle or pigs, or even rabbits, there is always a provision for collecting the animal urine for organic fertilizer.
"The urine is kept for 15 days in a container in order to allow it to ferment and it is then diluted with water in a ration of 1:2 or 1:4 depending on the kind of plant and type of soil to fertilize," Ajedra emphasized.
Fertilizer from urine is applied in liquid form, about six inches from the plant and it is used for top dressing.
This gives the plant the ability to make more food (protein) through photosynthesis thereby allowing the plant (crop) to grow with vigour to outwit pests and diseases.
"When you apply the industrial chemical fertilizer, it will only last for one year and you will have to apply it again in the next season. but when you apply organic fertilizer, you will have a living soil. I advise fellow farmers to embrace organic fertilizer," says Ajedra.
Ajedra however cautioned that the use of fertilizer from human urine may find difficulty in attracting massive demand due to the psychological issues associated with human waste.
“It is just like the animals that do not eat the grass where their urine or droppings are spread, humans have the same psychology that turns them off from organic fertilizers made from human waste. In India, people abandoned fertilizer because it was made from human feaces!” he added.
Viko Zumurah, a native neighbouring sprawling Bidibidi refugee settlement in Yumbe district where they share a borehole with the South Sudan refugees for irrigation and other domestic use, says that a cheap source of organic fertilizer would boost their cabbage and vegetable farms.
For now Zumurah and her colleagues only rely on the natural regeneration of the soil by rotating the crops and planting in shifts.
Dr Onesmus Semalulu, a prominent researcher at National Agricultural Research Organization (NARO) who is overseeing the trials, said the key challenge they encountered was related to bad weather of a prolonged dry spell attributable to climate change.
“When you apply fertilizer and there is no rain, you can not get the required result because the crop cannot absorb the fertilizer as expected,” he explained.
Dr Niwagaba and his team used both liquid urine and dehydrated urine and Diammonium Phosphate (DAP) a commercially available fertilizer in order to study the difference.
Dr Semalulu disclosed that there was higher nutrient volume in dry fertilizer i.e. 2.1% to 2.7% nitrogen than in liquid fertilizer which contains about 0.2% to 0.9% nitrogen.
“This is a big difference and because of this difference, you get better results when you use dry fertilizer from urine than when you use the urine in liquid form,” he noted.
Results of this study show that application of dehydrated urine consistently improved maize growth and yield, reflected in plant height, leaf size, stem circumference and shoot biomass in some cases rising up to 45.8%.
The urine-based fertilizer is seen as a viable solution to eliminate two problems- the poor agricultural yield and the sanitation challenge.
When urine is poorly disposed, it ends up with rain water in the water sources to cause pollution and growth of weeds in water bodies which is another environmental concern impacting on local ecosystems, biodiversity and household hygiene.
The effects are many but the most affected are the poorest in society, especially women and children in developing countries who suffer most from waterborne diseases and the damaged environment.
The last polio outbreak in Uganda in 2021 was confirmed after positive laboratory tests from environmental samples collected from sewerage plants in Bugolobi and Lubigi in Kampala.
The World Health Organisation in a joint report with UNICEF in 2003 stated that, about two million people die every year due to diarrhoeal diseases; most of them are children less than 5 years of age.
The most hit are the populations in developing countries, living in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants.
Providing access to sufficient quantities of safe water, sanitary disposal facilities and introducing sound hygiene behaviors seen as important to reduce the burden of disease caused by these risk factors
Dr Semalulu however cautioned that the period for their research was yet insufficient to draw conclusions for practical application of dry urine fertilizer for farmers.
He said the research needs to be repeated for another three or more seasons for a better empirical evaluation to allow the scientists to speak with confidence, a cumbersome experiment that could be hampered by lack of funding.
Dr Niwagaba pledged to continue with the research until a logical conclusion is reached.
“I started this with savings from my personal coffers. In fact, the laboratory has been set outside Makerere university premises because it could not support our research and I was unable to secure sponsorship from outside,” he pointed out.
Urine Collection challenge
The challenges associated with the collection of enough quantities of urine for the research hinge onto the fact that urine is poorly disposed of in the squalid settings of the suburbs of the urban and rural areas where sanitary facilities are poor and insufficient and open disposal of human waste is rampant.
For now, the annual student graduation ceremony is the single biggest event from which the researcher and his team collect the biggest amount of specimen from the public toilets used for the occasion.
“Urine has been used as fertilizer in India and China for hundreds of years. Even in Uganda, some people have used urine in different ways. But when it comes to large scale application of urine, the quantities that one has to apply in order to achieve certain fertilizing value are quite high,” he explained.
Niwagaba said this has made it difficult for the people to adopt urine as the best option for fertilizer in agriculture production.
The research was therefore set out to find optimal ways to collect the raw material i.e. urine and to process and apply in crop fields and horticulture.
“We collect urine which is undiluted (best urine for this purpose is from men’s urinals). We treat it by using acid or alkaline to block the conversion of the urine into ammonia,” he said.
The treatment with acid or alkaline stabilizes the urine so that it is not lost through the ammonia escaping into the air.
Then the water in the urine is evaporated through sun drying and the resulting solid fertilizer is used for crop growing.
In conducting field tests with researchers from the national agricultural research organization (NARO) using maize as test crop, the results of the experiments have been phenomenal.
“In some fields we have achieved results of between 20% to 50% increase in production. Agricultural lands are becoming more and more infertile, the productivity per acreage is going lower and there is growing demand to apply agricultural inputs including fertilizers,” added Niwagaba.
He noted that fertilizer production in the region is very low and most commercial fertilizer used in Uganda is imported from war ravaged Ukraine, Russia and north African countries where the rocks are phosphorous.
The costs of the imported fertilizers are too high, making it prohibitive for farmers to acquire and use in their crop fields.
Land fragmentation that is negating efforts to promote commercial farming based on the governments four-acre model also necessitates the correct application of fertilizers to boost productivity.
Niwagaba’s research is work in progress as it is still in its infancy but the enthusiasm among urban farmers in down-town Kampala who have shown eagerness for the products is a pointer that an elusive solution to the fertilizer headache for farmers and urban sanitation could be around the corner.
