Despite the dramatic hike in fertiliser prices over recent months, malting barley growers are being strongly urged to maintain nitrogen (N) rates at recommended levels.
Eoin Lyons, Teagasc/Boortmalt joint programme advisor, discussed this issue on a recent edition of the Tillage Edge podcast.
He said: “N applications on malting crops are already at a reduced rate, relative to other spring barley crops. So dropping this rate further could compromise final yields.
“It should never be overlooked that malting barley is a premium product. As a consequence, it will always secure a premium price.
“On that basis, there is no economic justification to reduce N application rates below recommended levels.”
According to Lyons, some growers may wish to come back in with a second split of potash (K). He advised that such an approach should be carried out on the basis of the projected total K offtake from the crop, including straw.
“So a malting barley crop yielding 3t/ac will require a fertiliser application of 85kg K/ha, simply to match the envisaged levels of K offtake at harvest,” he explained.
Micronutrients and malting barley
Turning to the issue of micronutrients, Lyons confirmed that these are important considerations, if a particular soil is deficient in them.
“An application of micronutrients should be based on a soil test result,” he said.
“Field history is also important. The most prevalent micronutrient deficiency that I would see cropping up with spring barley crops is manganese-related.
“Instances of it will be seen in all crops in most years. There are a number of factors that can trigger a manganese deficiency in crops. These include poor seed beds, loose seed beds, low soil temperatures, dry or drought conditions and high soil pH values.
“This latter point is particularly relevant in soils across the midlands.
“This year seed beds have been excellent, they have been well consolidated. So I can’t see any micronutrient issues cropping up to this stage, from that point of view.
“But there is still a long way to go, from the point of view of the current growing season. Lower temperatures could continue. And we could see a drought scenario unfolding over the coming weeks. We just don’t know.
“And, obviously, for growers on those high pH soils, there is going to be a certain amount of lock-up, where micronutrient availability is concerned,” he concluded.