Farmers need to raise their game and stop wasting nitrogen

Three-quarters of the N put into Irish soils is not utilised, costing farmers millions and damaging the environment — but there are ways to cut the losses

It might make for unpleasant reading, but millions of euro worth of nitrogen is being wasted on Irish farms each year. With just a 20pc of soil in optimum condition to utilise the nitrogen applied to it, farmers are seeing this valuable input literally wash down the drain or escape into the atmosphere.

However, with pressure ramping up on agriculture to raise its game on emissions, cleaning up our act in this area is can no longer be kicked down the road.

As Teagasc researcher David Wall explained in stark terms to farmers at the National Sheep Conference last week, “if we maintain our stock, which are the lifeblood of our rural economy and farming systems, we have to tackle the other side of the pie — the other 40pc of agri emissions that come from nitrogen by and large”.

Despite shooting up in recent years on the back of dairy expansion, nitrogen use on Irish farms had been static since the 1980s.

However, over the same period sales of other critical nutrients such as P and K and lime fell dramatically.

“An awful lot of damage was done to soil fertility on farms over that period,” Wall told farmers.

Looking at how much nitrogen is actually utilised on Irish farms, he said: “A lot of people wouldn’t believe me if I said that it’s probably in the region of just 25pc across all grassland.”

So just a quarter of the nitrogen we put into the system is actually recovered in an end product — milk or meat.

Such a shocking statistic demands immediate action, Wall stressed, pointing out that improving nitrogen efficiency would keep more money in farmers’ pockets, grow more grass and reduce emissions.

A reduction in N fertiliser of 10kg/ ha by implementing key changes on farm will reduce farm emissions by 1pc and improve income by €10/ha.

Lime

According to Wall, lime is where every farmer should start, describing it as the “foundation of soil fertility” and critical to making nutrients such as nitrogen work as they should.

“We have acidic soils and high rainfall, particularly in the west of the country,” he said.

Maintaining grassland soils within the optimum pH range of 6.3 creates a suitable environment for microorganisms and earthworms to thrive and break down plant residues, animal manures and organic matter. This helps to release stored soil nutrients such as N, P, K, sulphur