Urine can be used as fertilizer – agriculturist
Rev Dr Kwesi Biney, an agriculturist and evangelist, has called for the use of human urine as fertilizer by farmers.
He is contained in a in a paper to the Ministry of Food and Agriculture.
Rev. Dr. Biney said it was estimated urine contained between 5.2 and 9.6 grammes of nitrogen per person per day and between 75 percent and 90 percent of this was excreted as urea.
Urine, he said, was also estimated to contain 2.5 to 3.6 grammes of potassium and 0.6 to 1.1 grammes phosphate as plant available phosphate ions.
“From research findings it is established that the PH of fresh urine is approximately six, with the PH increasing as urea hydrolyses to ammonia”, he said, adding “The PH stored in urine is often slightly alkaline”.
Rev. Dr. Biney said notwithstanding the effectiveness and economically-cheap aspect of human urine as a form of fertilizer, most countries including Ghana did not want to apply it, mostly for growing vegetables.
On how safe the use of urine on crops as well as its smell, Rev. Dr. Biney said “urine per se is sterile when it is in the human body and of importance is to collect it separately from faeces”.
He said the separation of urine from faeces could be done right from the collection stages and the farmer could do that by urinating into a bucket or any other container.
The farmer could keep it sealed whenever the commodity is not in use to reduce its smell and loss of nitrogen to volatilization of ammonia, which is a breakdown product of urea.
Another method of separation, Rev. Dr. Biney said, was to use composting toilet, designed to automatically separate solid from liquid human waste. “From research results, it has been concluded that the pathogens that may be transmitted through urine are rarely sufficiently common to constitute a health risk in humans in temperate climate”, he said.
On how much urine to use and when to apply, Rev. Dr Biney said the amounts would vary depending upon the nutrients in the urine, which to some extent also depended upon the food the person ate.
Many who eat less protein will have less nitrogen in urine, he said, adding “biologically urine is used by the body as a balancing medium for liquids and salts and the quantum of urine therefore varies with time, person, and situation”.
Urine produced by a person in a day, he said, could be applied to a square meter of land per growing season.
He said if all urine was collected, it might be possible to fertilize 300-400 meter square of crops per person per year.