Should you be spreading protected urea this summer?

As we move into the second half of the grazing season, beef farmers will be turning their attention towards grass supply in a bid to extend their grazing season.

With the fine weather over the weekend, a lot of farmers lifted their second cut of silage or left paddocks aside for hay.

Now it is time for farmers to turn their eye towards fertilising these paddocks again, using protected urea as the source.

Protected urea is urea nitrogen (N) fertiliser with the addition of a urease inhibitor which reduces ammonia N (NH₃) losses by up to 78%.

Protected urea can grow more grass than either calcium ammonium nitrate (CAN) or standard urea, as well as reducing greenhouse gas (GHG) and ammonia emissions within agriculture.

This can allow suckler farms can reduce emissions by 1-2%, at a spreading rate of 60-80 kg N/ha.

Protected urea is also more cost-effective per kg than other fertilisers such as CAN, while also reducing N loss from 15% (standard urea) to 3% (protected urea), therefore being 12% more effective.

Applying protected urea

The fertiliser needs careful spreading for best results, due to its lower density (0.75 kg/L vs. 1.0–1.2 for other fertilisers).

While protected urea releases N slowly, the urease inhibitor makes it more effective than CAN during this process.

Farmers should ensure fertiliser spreaders are in good working condition, checking components such as the vanes.

If possible, farmers should also be calibrating their spreaders as the density of protected urea requires a narrower spreading channel.

Due to the higher N content compared to CAN. farmers are reminded that the application rates will be lower.

Farmers should also note that when buying protected urea, larger granules indicates that fertiliser is of better quality.

Johnstown study

Teagasc’s Johnstown Castle in Co. Wexford carried out a long-term trial on the effectiveness of protected urea.

Results showed that grass grown by protected urea has been greater than standard urea in seven out of the eight years of the trial.

The study showed that protected urea grew 13% more grass on average in comparison to standard urea, and CAN yielded 9% more than standard urea.

P’s and K’s

Farmers should also be optimising left-over cattle slurry where possible, as a a great source of phosphorus (P) and potassium (K).

Cattle slurry also supplies N, and by using low emission slurry spreading (LESS), farmers can double their N availability compared to splash plates and reduce ammonia emissions simultaneously.

Target paddocks low on P’s and K’s for slurry use or fields that were cut for silage.

Farmer are also being reminded to use sulphur this summer, spreading between six and 12 units/ac, depending on target yields, in a bid to improve N efficiency and dry matter.