Crop nutrition will play a vital role in the success of 2020 spring barley crops, with growers encouraged to re-evaluate their programmes after the effects of the heavy winter rainfall.
Having been leached from soils as a result of the significant winter downpours seen across the UK, levels of nitrogen and sulphur are now considerably lower than in previous seasons.
As a result, planning crop nutrition, reviewing nitrogen rates and timings, and considering foliar micronutrients and biostimulants are just some of the measures growers should take in order to maximise the performance of spring barley crops.
Nitrogen rates
“Most malting spring barley will have received all of its nitrogen by now, with the rate very much linked to the grain contract and yield potential,” says Edward Downing, Frontier’s national crop nutrition technical manager.
“However, the large area of spring barley this year means a significant proportion will be destined for the feed market. This means growers will need to be more generous with nitrogen, usually in the region of an extra 30-40kgs per hectare, in order to maximise economic yield.”
Edward explains that this is supported further this season, as crops need to be provided with more nitrogen to make up for the shortfall in soil nitrogen levels. “Moving down one SNS index because of the high winter rainfall increases the nitrogen recommendation by a further 20-30kgs/ha. However, it is important to remain compliant with the N max limit.
“In feed barley, I would also encourage splitting nitrogen applications into three to apply this bigger total dosage without significantly increasing the risk of lodging,” he adds.
“This third application around early stem extension gives more of an opportunity to assess the season we’re in and the potential performance of the crop to adjust the amount that is applied.
“If conditions or the crop aren’t great it may not even need to be applied, whereas if everything looks good then a reasonable dose would be sensible.”
Micronutrients
Overall plant growth is impacted by a wide range of nutrients and, if all aren’t supplied in the correct amounts, yield will be impacted.
“It’s therefore important to not just focus on nitrogen, but also micronutrients such as manganese, zinc and copper, which will be especially important this season,” explains Jamie Stotzka, Frontier’s soil and plant health specialist.
“Broad spectrum tissue testing and ideally soil sampling can be used to determine any low or deficient nutrients, which then allows appropriate nutrition plans to be developed.”
She explains manganese assists in nitrogen utilisation as well as promoting photosynthesis, and copper is essential in ear fertility, grain set and cell wall development.
“Zinc is also crucial, helping with root growth and disease resistance to create a fully functioning healthy plant,” she adds.
Jamie notes biostimulants can be very useful to complement micronutrient applications because they stimulate natural processes that benefit nutrient uptake efficiency, as well as tolerance to abiotic stress and/or crop quality.
“This year I would recommend considering foliar applications of pidolic acid, which acts as a signalling compound and plays a key part in the nitrogen assimilation process by keeping the cycle in balance.
“Pidolic acid also primes plants to rapidly recover from stress once limiting factors have been addressed, and can be applied with T2 fungicide applications.”
In the field
In light of the challenges faced so far this season and with the increased spring barley area, assessing soil conditions is crucial. Frontier agronomist, Marcus Mann, is working with growers to help improve yields, particularly on soils that have struggled to reach malting specifications.
“Heavier clay soils that have historically retained better moisture have resulted in higher grain nitrogen. We’re increasing nitrogen rates and improving its utilisation to further enhance yields.
Marcus also notes that, should the season turn dry, growers may be required to consider a three-split programme and time it around moisture being present.
“For those using liquid fertiliser for nitrogen applications, we’re including Limus Clear® to minimise the risk of nitrogen volatilisation.
“To complement better nitrogen utilisation, early PGR and phosphite applications will help enhance rooting, resulting in better access to water and nutrients. This will also have additional benefits including stronger crown roots, which will reduce the risk of root-based lodging and enhance tiller survival”
