CropDoctor North By Robert Harris

The clock is ticking for spring barley drilling in Scotland – but patience and effective early agronomy will be rewarded, said Agrovista technical manager, John Murrie, this week.

Unlike most areas south of the Border, cropping plans in Scotland remain relatively intact, with 85-90% of the intended winter area drilled. “We don’t grow as many winter crops as further south and we made an earlier start as we don’t face the same blackgrass problem,” said John.

“Most winter wheat was drilled before the weather turned. So, while we do have more spring barley to drill than usual, it’s manageable enough.”

Heavier soils will take some drying, but there is no rush yet. “We usually sow from mid-March to mid-April and it is possible to establish a reasonable spring barley crop towards the end of April. This is not going to be an early season, but if the weather improves soon we should be OK,” he added.

It will pay to wait for soils to dry sufficiently and to start warming up. Spring barley struggles in cold, wet soils, which can severely affect potential as it has a short growing season and little time to compensate.

Wet soils are also prone to compaction, so if topsoil can be rolled into a sausage don’t drill, John advised. “As far as possible, we need to avoid anything that might check the crop. A seed rate of 350 seeds/sq m is ideal in good seed-beds up to mid-April. After that, rates should be increased, but only by 5-10%.

“Maltsters need good bold grain. Sowing too thick a crop will result in smaller thin grains. That is a particular risk with crops sown by weight, which tend to result in quite high seed rates,” he pointed out.

Care is also needed with newer varieties, such as Laureate, Diablo and Sassy, as they tiller more profusely than the old favourite, Concerto. “This will be their first big season on many farms, so growers need to bear this in mind. Sufficient nitrogen, phosphate and potash should be applied to the seed-bed to give crops the best start. Early agronomy is also key."

John advised taking a tissue test prior to GS 30 to assess nutrient status and to treat accordingly at that timing, along with the fungicide. “A lot of soils in Scotland are short of potassium, which helps water regulation in plants, so topping up with a foliar treatment will help in a dry summer.”

Another key ingredient in the tank mix this season is plant growth regulator. “Concerto is stiff and you rarely saw a lodged crop, but I would apply Canopy as routine on Laureate, Diablo and Sassy at GS30.”

He also recommended Terra-Sorb Foliar Extra at this timing, a blend of 18 essential amino acids that are readily assimilated by plants. These boost physiological processes in plants leading to improved root and shoot growth to help mitigate the effects of deficiency, stress and drought.

“The product has been very beneficial, especially when going into a dry period,” added John. “It ensured roots keep going down and are doing their work, and also enhanced the uptake of key minerals like manganese, zinc and copper, especially during times of stress.

“In 2018, a very drought-stressed year, we found Terra-Sorb to be highly useful. Even last year, in good growing conditions in field-scale trials there was a reduction in screening levels when applied early.

“We have a myriad of trial results showing how well it works and I’m lucky to have some very forward-thinking clients who are spreading the word. I see it very much as a 'stress-buster' which, for a few £/ha, provides very good insurance.”

Sow a cover crop?

Some fields, particularly heavy soils after potatoes or energy beet, are in a very poor state and may not be fit to be drilled even by the end of April, added John.

“Spring crops mauled into heavy soils do not work. You risk throwing good money after bad and in such cases it would be better to establish a cover crop in May, or June to help the soil dry out and recover.

“It will also help restructure soils, add organic matter and help pump out water through the leaves, leaving soil in much better condition come the summer, which will benefit following crops significantly.”

There is no need for a complicated mix – these can increase costs for no additional benefit, he maintained. “We base a lot of our mixes around black oats, which are deep-rooters helping to condition the soil at depth and to aid drainage.”

Sprinter Max is a mixture of black oats and Phacelia. The latter is an effective partner, as it is shallower rooting and conditions the topsoil and suppresses weeds.

Other species, such as berseem clover, can be used where more intensive deep conditioning is required, while vetch offers fast growing biomass and can fix nitrogen well, he said.