Adaptability to season is key to spring barley success

Focusing on establishment and maintaining high tiller numbers is key to high barley yields, but be reactive to the conditions, says Ron Granger, Limagrain UK’s arable technical manager.

Spring barley is a valuable crop in the rotation, which can record good yield potential and high income with lower inputs, compared to many autumn sown cereals.

Indeed, 2021 saw some very high yields from spring barley crops across the UK, as a result of a very good growing season, allowing for good establishment and healthy crop growth.

Confidence in the crop remains; the AHDB Early Bird Survey (source: Defra) suggests that the area of spring barley grown in 2021 was 756Kha, and there is no reason that areas for 2022 should differ greatly.

To ensure the success of the crop, it’s worth revisiting some of the key agronomic principles for establishment and maintaining high tiller counts – and recognise when to adapt these to accommodate conditions at the time.

Know your local market requirements

determine agronomic inputs. For example, understanding the correct nutrition for hitting desirable grain nitrogen percentage for the different malting barley markets.

Also, depending on the locality and opportunities for export, the type of barley crop will be determined by the market sector targeted. These markets are dependent on the grain nitrogen percentage: • Distilling – 1.65% or lower • Brewing – 1.65–1.85% • Grain distilling – 1.85% plus • Feed – N/A.

Choose the right variety

Variety choice is usually determined by the end-use or contract chosen. Look at the MBC malting barley approved list for 2022, to con rm which varieties are fully approved and which are still under test for the individual market requirements.

Dual use varieties, such as LG Diablo, can be used for either brewing or distilling; LG Diablo is the highest yielding dual-use variety available, which also offers feed potential.

Time of drilling

Patience is required to wait for the right conditions for for the right conditions for drilling – when weather drilling – when weather and/or soil conditions allow for good seedbed preparation – in combination with rising combination with rising soil and air temperatures. soil and air temperatures. Limagrain UK trials show Limagrain UK trials show that earlier drilling in the spring that earlier drilling in the spring encourages higher yields on lighter, free draining land that will dry and warm up faster than heavier, wetter soil types. But drilling early significantly increases the risk of disease, so consider varieties with strong disease resistance for this situation.

Seed rate

Trials carried out by Limagrain, comparing variety seed rates over various seasons and regions, show that with the more vigorous, higher tillering varieties, the optimum seed rate is 350 seeds/m2 when drilling in ideal conditions around mid-March.

This gure can be adjusted up or down depending on: • Weather • Drilling date • Seedbed quality • Moisture availability • The grower’s own experience on individual sites. A lower rate of 300–325 seeds/ m2 would sufice if drilling into an ‘onion bed’ in March. If forced to drill into April, due to the weather or for agronomic reasons such as black-grass control, push rates up to 400–450 seeds/m2.

Maintaining high tiller numbers

After establishment, the most important factor for achieving high yield potential is high final tiller or ear counts.

The high yields of 2019 and 2021 were achieved due to above average, higher final tiller counts, backing up the theory that final ear counts approaching 800/m2 achieve the highest yield potential.

The AHDB Barley Growth Guide suggests that the final ear target population should be around 775/m2 (three shoots/plant), however this is often underachieved, impacting on final yields.

Nitrogen and tiller numbers

Spring barley has traditionally been a lower input crop with growers reluctant to increase nitrogen application rates, particularly in malting barley crops, through fear of exceeding maltsters’ grain nitrogen limits.

However, Limagrain trials – carried out over several years – show the benefit of using higher nitrogen rates of 150kg/ha, based on a split nitrogen application of a standard 120kg/ha in the seedbed, plus an additional 30kg/ha at tillering, when compared to a standard seedbed application of 120kg/ha.

This approach produced higher yields, without exceeding grain nitrogen percentage. High yielding LG Diablo responds well to the higher nitrogen levels, as nitrogen grain content dilution is achievable.

Care should be taken on lighter soil types that are more prone to stress – here the majority of the standard nitrogen regime should be targeted early in the plant’s life.

It’s important to be adaptable regarding the crop’s input regime, especially when crops are under stress from a period of drought. Crops that are stressed and not actively growing do not have the ability to utilise nutrients efficiently from the soil, and may bene t from a foliar application.

Macro and micro nutrition

Macronutrients such as phosphate, potash, magnesium and sulphur should be applied either in the seedbed or soon after drilling, for strong rooting and early plant growth. Micronutrients – manganese, zinc, copper, iron and boron – can be applied at the stem extension phase of growth into flowering.

Tissue analysis is always useful if targeting a very high yielding crop. FG