A Pembrokeshire dairy farmer has made a saving of 63% on his fertiliser costs without loss of grass yield by switching to a foliar application system.

Andrew Rees had already improved soil health and grazing management at Moor Farm, Walwyn’s Castle, where he grows grass and multi-species swards for grazing his herd of 350 British Friesians.

Improving nitrogen use efficiency, by applying liquid fertiliser directly to the leaves of the grass sward, was the natural next stage, he says.

After a great deal of research into using foliar application in a grassland situation, in 2020 the business invested £36,000 in equipment designed for foliar application.

“You might say we jumped in with both feet,’’ says Mr Rees, who farms with his wife, Vicky, and his mother, Jean.

But that bold decision has paid off – in 2021 his total nitrogen (N) use across the milking platform was 82kg/hectare (ha) compared to 220kg in 2019, when granular fertiliser was applied.

“Overall, we have made a 63% saving on fertiliser,’’ calculates Mr Rees, who farms 155 hectares.

Using urea instead of higher priced fertiliser per unit of N, such as ammonium nitrate, has allowed further cost savings.

Mr Rees’ figures show that the farm utilised 12tDM/ha of pasture in 2021 compared to 11.6t in 2019.

He also reckons there is more clover in the sward.

“I don’t have any empirical evidence of that but I can see that there is more clover about.’’

In foliar application, grass cover should be at a minimum of 2200 kg dry matter (DM)/ha – equivalent to a height of 7.5cm or 3-4 inches because plants absorb the essential elements through their leaves.

If there is sufficient leaf area, repeated experience has shown the same response from 40% less N applied via foliar application compared to granular.

To improve the efficiency gains, by improving nutrient uptake, Mr Rees adds humic acid or molasses to the urea solution.

The change in system did require high upfront investment – the capital cost of the applicator was considerably higher than a standard disc spinner but this has already been recouped through fertiliser savings, and the machine has other uses too, says Mr Rees.

“We have used it for over-sowing chicory, plantain and clover, the seed can be applied at the same time as the fertiliser.’’

Twelve per cent of his land is now growing multi-species leys and some of the ryegrass leys are oversown with clovers, chicory and plantain.

“Twenty per cent of the farm will have some type of herb in it,’’ says Mr Rees.

This measure in combination with other improvements to soil and grassland management have played a role in supporting nitrogen use efficiency, he adds.

“You will get a gain from switching from granular to foliar application but you are not going to get the same level of gains without focusing on other aspects that might be limiting nutrient uptake by the plant.’’

Although the cost savings from foliar application have been significant for Mr Rees, he says there is more to making better use of nitrogen than the financial benefits.

“The cost savings can’t be ignored but we need to be able to meet nitrate legislation and a way to do that is to do what we can to reduce the amount of N we are losing to the environment.

“By feeding the plant what it needs, we are not losing anything by leaching.’’