Mr. Nitin Gadkari, the minister for Road Transport & Highways, Government of India, has said that urine banks would be set up in every taluk in India, so that urine can be collected from individual citizens and processed to produce urea fertilizer. According to the minister, this will be a step towards minimizing the import of urea in India.

The minister said that farmers would be expected to collect the urine in 10-litre plastic cans provided by the government and bring them to taluk center, for which the farmer would get Rs. 1 per liter. Synthetically produced urea fertilizer has 45% nitrogen content.

Human urine has nitrogen content, and this is why the minister has been tempted to plan to use of urine as replacement for synthetic urea fertilizer. Synthetic urea projects of economic capacity from natural gas have now been set up in India with an investment of around Rs. 5000 crores each. India is now one of the largest importers of urea fertilizer in the world.

Since the statement has come from the minister in his official capacity, it is deemed to be considered to reflect the fertilizer policy planning measure of the government of India.
On reading the minister’s statement, many would wonder as to whether reducing the import of urea is a task as simple as this.

Of course, those who think that India is not adequately utilizing its large population of several millions of people and whose number is increasing at alarming rate would be thrilled at the above idea of the minister for finding a way to use the Indian population potential as an economical source! Those who have been saying that huge population of India is a blessing in disguise will applaud the minister for acting as a strong advocate of their cause to use human beings for productive purpose!

Import level of urea fertilizer

Urea is the richest source of nitrogen among the common dry fertilizers and is the most commonly used fertilizer in India.
Annual import of urea in India

Period: April to March Import

in million tonne

Import value

in Rs. crore

2014-15 8.7 15342
2015-16 8.4 15643
2016-17 5.4 7749

Urine as source of urea

Urine consists of approximately 98 percent water and 2 percent urea, which is made up of carbon, oxygen, nitrogen and hydrogen atoms.
In fresh undiluted human urine, the concentration of the following constituents in urine may be regarded as an accurate approximation:

· Urea: 9.3 gram per liter
· Creatinine: 0.670 gram per liter
· Sodium: 1.17 gram per liter
· Potassium: 0.750 gram per liter
· Chloride: 1.87 gram per liter
Conversion of urine to urea
The process involves three major steps

* Collection and storage

Urine makes up less than around 0.5 % of household wastewater. At community level and (urban) large-scale (where the risk for cross-contamination is high), urine needs to by hygienised before reuse.

Storage is a necessary step in the process of urine reuse, either directly after production or before central collection and treatment. Thus, several parameters must be taken into account.

Extended storage is the simplest, cheapest and most common method to treat urine with the aim of pathogen kill and nutrients recovery. Pathogen removal is achieved by a combination of the rise in pH and ammonium concentrations, high temperature and time. However, the costs for land and storage tanks can be significant.

Recommended storage time at temperatures varies between 4 to 20 deg C and one to six months respectively, for large-scale systems depending on the risk for cross-contamination (e.g., user habits, maintenance) and the type of crop to be fertilized.

* Pasteurization
The primary aim of this treatment stage is to eliminate the pathogens present in urine such as viruses, bacteria, and protozoa. Secondly, as temperature strongly influences enzymatic activity, pasteurization could be a solution to inhibit urease activity, if operating at the right temperature.
Failure to deactivate urease in the pasteurization stage of prototype would result in large quantities of ammonia being produced, putting the operator at risk

* Evaporation

To produce an effective fertilizer, the nutrients in urine need to be concentrated through an appropriate volume reduction technique.

Concentrating urine is also the best response to the problems of transportation and storage associated with the use of urine as a liquid fertilizer.
Risks of urea from urine
* As human urine contains ~98% water, it can be expensive to transport and store
* The nitrogen in stored urine is in the form of ammonia, which is prone to evaporation and requires special handling during storage and handling
* No established process technology and operating plant anywhere in the world.
* Social taboo associated with handling and using urine-based urea in the production of food crops.

Mode of application as fertilizer
After storage or pasteurization has eliminated pathogens, there is a chance of recontamination, leading to the advice that urine should only ever be spread on the soil rather than edible parts of the plants.

Urine application has been shown to increase the electrical conductivity of the soil, which, depending on the levels applied, can hurt the crop
Other risks to consider are the prevalence of heavy metals in urine although these are low compared with other organic fertilizer.

Research Efforts

Research Institutions are now conducting research to examine the safety and efficacy of using urine-derived fertilizers in agriculture. Research efforts are only in the development stage.

Is it a feasible or a ridiculous idea. ?

The proposal of the minister to use urine as urea fertilizer is likely to receive derisive laughter not only from a layman but even from technologists.

Many persons would call it as a ridiculous idea and may even be tempted to criticise Modi government for advancing such suggestions. Any idea is worthwhile, only if it can be implemented smoothly and would make economic sense in a commercial facility. These aspects have not been studied carefully yet.

Urine to urea project is yet to be validated scientifically from productivity and utility factors.

Minister should have exercised some caution before airing his views in public, making everyone think it is a policy measure of Modi government. The minister should have ordered some specific research efforts and feasibility studies and thrown the results for public debate before announcing this measure.

It often happens that a vague, careless suggestion of a minister without sustained study, deflect from the public attention otherwise excellent work of the government and particular minister.