No rush to get nitrogen out on to winter barley crops just yet

Teagasc tillage advisors are confirming that most winter barley crops are looking well at the present time.

Many crops in both Leinster and Munster have achieved establishment rates in excess of 75%. This includes both two-row and hybrid varieties.

Crops sown out in September are showing heavy tillering rates. But irrespective of growth stage, Teagasc tillage specialists are advising that nitrogen (N) should not be sown out on winter barley ground until the end of February, at the earliest.

Agronomy update

These were some of the main points discussed at this week’s Teagasc Winter Crop Agronomy update, which was hosted as a webinar event.

Oak Park based Ritchie Hackett said that February (as opposed to March) nitrogen applications made no difference to final crop yields.

Other advisors taking part in the webinar agreed, adding that ground conditions are currently too cold and wet to facilitate any fertiliser applications.

Hackett said:

“No difference should be made when it comes to managing two-row barley varieties versus hybrids. Each crop should be manged on its own individual merit. This advice is equally relevant where both fertiliser and fungicide applications are concerned.

Hybrids tend to mature that little bit earlier than is the case with two-row barley varieties.

Fertiliser programmes

All the Teagasc staff taking part in the webinar stressed the need for fertiliser programmes to be based on soil test results.

As a general rule of thumb, winter barley crops should receive 40 units of N/ac with appropriate P (phosphorus) and K (potassium) before growth stage 31. This will be sufficient to boost the crop and facilitate tillering.

After assessment of the crop, a split dressing of fertiliser might be considered, if it needs a boost.

A further 80 to 100 units of N/ac should be added during the stem extension growth stages. These will take place during April.

Checking for weed infestations

Growers were also advised to walk all crops now, to check on weed infestation levels. If a herbicide treatment is required, its formulation should be focused on controlling those weeds that are the most competitive in nature.

For example, cleavers is a more competitive weed in barley than the likes of groundsel. Growers were advised to check the Teagasc competitive index chart to check the significance of individual weed species.

A cleavers population of just 1.5 plants per m² can reduce barley crop yields by as much as 5%.