Dairy farmers are being warned against pulling back on grassland fertiliser applications to prevent clamp losses later in the year.

David Newton, technical manager at Timac Agro UK says producers need to take a long-term view when it comes to inputs and assess the consequences if applications of fertiliser are reduced, including a more costly winter feed bill.

“Despite the rising input costs, home grown forage remains the cheapest form of feed available to dairy farmers, as long as grass continues to receive nutrients throughout the season,” explains Mr Newton.

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“After a mild spring, grass growth looks promising, which should see good first and second cuts in the clamp. But we need to maintain this momentum for the remainder of the season.

“If we continue to feed grass well with the right nutrients, yields can be pushed above 20kg of dry matter (DM) per kg of nitrogen (N),” he notes.

Rather than routinely applying fertiliser to cover the first cuts of silage, Mr Newton says farmers need to look at adapting applications to promote N use efficiency in different environments. This can include delaying applications, working with manures and ensuring soil health works in their favour.

To help navigate these decisions, he signposted the new tool from AHDB.

“The cost benefit calculator for nitrogen use on grassland takes into account fertiliser and feed prices, calculates the cost of nitrogen applications and then compares this with the feed value of grass.

“You simply input your figures, such as your fertiliser price and the amount of nitrogen you plan to apply, and the tool does all the calculations for you. This should help formulate a revised crop nutrition programme in line with the season and price changes.”

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Alongside artificial fertiliser, farmyard manures (FYM), and slurry will be able to provide additional P and K, but it needs to be applied with caution.

“Any manure should be tested before spreading, especially this year, as producers need to comply with Farming Rules for Water and Regulations,” he adds.

“By testing manure, you see exactly what is going into your system and can therefore make savings in fertiliser applications. Figures in RB209 and other guides are national averages and can differ wildly from what is found in an individual situation.”

He added that on soils with a P index of 3 or above, farmers need to be able to justify its use which should be treated the same as an application of an artificial fertiliser.

“We don’t want to see the impact of the current high prices impacting winter feeding, so by paying close attention to the nutritional needs of the grass leading up to and during each cut, the quality and quantity of the cut shouldn’t have to suffer,” Mr Newton concludes.