Hybrid barley growers facing this season’s high nitrogen (N) fertiliser prices could help the crop use the nutrient even more efficiently by monitoring soil temperatures to fine-tune the timing of the first application, according to Syngenta’s seeds technical expert for hybrid barley, Ben Urquhart.
Hybrid barley is already recognised for using N efficiently to build high yields – requiring no more N than conventional winter feed barley – but with high fertiliser prices this season, he said there’s an added focus on getting the most from every kilogram of N applied.
By checking soil temperatures to ensure the first N application is only made once warm enough for spring root growth to have started – provided that other conditions are also suitable – he added that the applied N stands the best chance of being absorbed rapidly by the plant, rather than sitting unused in the soil.
“The first N application in hybrid barley, typically around mid-tillering (GS25), is key for feeding the crop’s spring hybrid vigour and supporting the optimum number of tillers for yield,” Mr Urquhart said.
“It’s particularly important because hybrid barley is sown at a lower seed rate than conventional winter barley. Establishing its vigorous canopy with this first N application also helps it to suppress black-grass, ryegrass and certain types of brome.
“Typically, spring root growth begins when the soil temperature in the root zone, approximately 5.0 to 10cm deep, reaches 4.5 to 5.0C,” he added. “Therefore, check temperatures at this depth regularly. By combining the knowledge that the first N application in hybrid barley should go on around GS25, with the correct root zone temperature having also been reached for root growth to have started, it brings greater precision to targeting N more efficiently.”
Provided that field conditions are suitable – for example not waterlogged, covered in snow or frozen – Mr Urquhart said Syngenta’s overall guidance for hybrid barley was to apply 30 per cent of the season’s total N dose at this first timing, followed by 50 per cent at or just before GS31, and the final 20 per cent two to three weeks after that, typically by the end of April.
To ease workloads or to boost thin crops, an alternative is to apply 50 per cent at the GS25 timing and 50 per cent at or just before GS31.
“The actual kg/ha of N required at each timing will depend on individual field and crop situations,” Mr Urquhart added. “Growers should work with their agronomist to determine this.”
To provide an insight into rising soil temperatures, Syngenta is tracking these at different locations around the UK during the rest of winter and into spring.
“Soil temperatures can vary in individual fields depending on multiple factors,” Mr Urquhart said, “so growers should still monitor their own crops. But the aim of our monitoring is to provide a benchmark of rising soil temperatures in different locations and results will be shared on the Syngenta UK website, via social media and in e-mail newsletters.”
