As March comes upon us, there is plenty to be done in fields. Last week the Irish Tillage and Land Use Society’s, spring workshop provided advice for the season ahead.

Brian Reilly of Drummonds talked attendees through the winter crops on the Drummonds trial site in Termonfeckin in Co Louth. He was keen to hold back forward wheat crops and eager to get nitrogen on to winter barley.

Following two years of wet winters, it’s unusual to hear talk about cutting back fertiliser on forward crops, but that is a common topic in the tillage world in recent weeks.

The winter wheat, barley and oats at the site were planted on 4 and 5 October, and crops were thick and very forward. It was great to be able to see such visible differences in varieties so early in the year.

All crops received Agriphos at a rate of five bags/ac to stubbles and were incorporated in ahead of sowing. This delivers about 23 units of phosphorus (P) and 55 units of potassium (K) per acre and gets crops off to a great start.

Brian noted that Agriphos, which is combusted poultry litter, helps to keep soil pH on track, as it is high in calcium. It also contains substantial levels of magnesium, sulphur and sodium, as well as a lot of trace elements which are good to provide to the crop from establishment. The product is spread with a fertiliser spreader and is a powder rather than a granule.

Potassium will be topped up on all crops to at least 100un/acre, to ensure good straw strength and a healthy crop.

Nitrogen (N) is all applied in liquid form. It’s a urea plus ammonium nitrate mix with sulphur. It was emphasised that liquid N needs to be applied to the ground and will have faster uptake than granules, so can be applied a little bit later.

Applying on a windy day can lead to N hitting the leaves and causing scorch and stress on the crop, so this should be avoided where possible.

Drummonds has cut N rates by about 15% due to savings on placement of fertiliser compared to granular fertiliser. On winter wheat, N will be applied in two splits at GS30 and then about 10 to 12 days later. 75un/ac will be applied at each split.

Holding back crops

Graham winter wheat at the Drummonds trial site.

The winter wheat crops at Drummonds were thick and looked healthy. They had all been treated with Firebird Met at 0.75L/ha for grass and broadleaved weeds and Cameo to control volunteer beans.

“Winter wheat is very proud at the moment. There’s a minimum of 700 to 900 tillers/m2,” Brian said.

He added that there are too many plants and said: “Stay out of fields until the second week of March. Let some tillers die off.”

If crops were hit by slugs or another pest, then they will need a nitrogen application earlier.

Those full crops will cause issues for disease control in the coming weeks if they remain very full.

Already Brian noted that Drummonds agronomists have seen yellow rust in wheat. A thinner crop should help to reduce disease levels, however, after this a good disease control programme is essential.

He commented that “sulphur is key for yield in wheat today”. Sulphur at T0, along with a strobilurin for rust is now almost essential on wheat in many agronomists’ opinions. Brian said Drummonds trials are showing a 0.5-0.6t/ha increase in yield from the inclusion of sulphur at T0 and added that it is even more important to include on older varieties like KWS Dawsum, Graham and Spearhead.

On a brighter note, there are some stronger varieties coming through, with resistance ratings of seven and eight to Septoria.

Growth regulation

Orcade and KWS Tardis winter barley at Drummonds trial site.

Looking at Spearhead and Champion, Brian noted that these varieties will most likely have massive canopies later in the season and plant growth regulation will have to be on the ball.

He said to “make sure you regulate early” and recommended strengthening the plant throughout the season rather than trying to stop it growing later in the season.

As a result, he recommended a Trinexapac-ethyl product like Moddus at GS30 and a product like Medax Max at GS32 to strengthen roots and nodes.

The agronomist also recommended cutting back on nitrogen by about 10% on varieties like Champion to reduce lodging risks.