Sustainability was the hot topic of discussion at the recent Moorepark Open Day. Understanding what sustainability is, is one thing, but implementing sustainable practices is another.
One sustainable practice – which was discussed at the open day by Teagasc’s Karl Richards – was the inclusion of protected urea in farm fertiliser plans.
Karl explained “that under high-emitting conditions you can loose almost 50% of urea as ammonia gas – that is half the nitrogen (N) you apply – which is costing you money”.
Whereas protected urea – which is urea coated with a chemical or the chemical can be put into the urea granule – slows down the N loss as the chemical attaches to the N.
Turning to an experiment completed by Teagasc, he said: “We tested two soils, one with urea applied and one with protected urea applied. The results showed no ammonia was emitted from the soil applied with the protected urea.”
Protected urea vs. CAN
A study was also completed to see if there was any difference on herbage production between protected urea and CAN.
“We found no significant difference, at all, in terms of yield or N uptake; so, it is identical to CAN in terms of the amount of grass it can grow and the amount of N that goes into the grass.
“In addition, the emissions from CAN are about 1.5% and the emissions associated with protected urea are 0.4%.
What this means is, if we were to convert half the CAN used in Ireland to protected urea, that equates to about half a megaton (500,000t) of carbon.
Continuing, he said: “Switching to protected urea is the largest measure in the climate action plan and the largest measure we have identified to reduce greenhouse gas emissions – outside of planting forest on your land.
“It is a very effective measure and is about 10c/kg of N cheaper than CAN; so, it saves you money and reduces greenhouse gas emissions.”
Advice to farmers
Karl concluded by giving some advice to farmers on the use of protected urea.
He said: “There is a problem putting phosphorus (P) with it because they don’t react well together. If you need to put on P and potassium (K), go with your compound and switch your straight N fertiliser to protected urea.”
Some products on the market have been found not to work as good as others.
However, the chemicals Teagasc are confident about are “NBPT and 2-NPT”.
If you are purchasing the product, ask does it contain one of these two chemicals and does it meet the EU fertiliser regulations.
“I understand it breaks down quicker than CAN but it remains just as effective in terms of N availability,” concluded Karl.