March Management of Winter and Spring Cereals
Michael McCarthy, Teagasc Business and Technology Tillage Advisor West Cork, has management advice on winter cereals. He recommends prioritising fertiliser application and weed control now. He advises on spring barley seed rates and reminds nitrates derogation farmers of their liming requirements
Establishment has been good in the majority of winter crops apart from those sown late. Fertiliser application and any remaining weed control will be the priority over the next few weeks when weather improves.
Winter barley – Fertiliser
Prioritise any crops with low plant counts and fields with low P and K levels for first fertiliser application. Amounts should be based on a recent soil test report. Apply in a compound with the first split of nitrogen (N), 50 kg/ha (40 units/ac), in early March and apply the main split by GS 31. On thin or backward crops first N can be earlier (start of growth) but application rate should be low as crop demand is small. Sulphur (15 kg/ha) and trace element deficiencies (based on soil analysis and field history) should be applied to all cereals before GS 31.
Plant Growth Regulator (PGR)
An application of CCC 1.5 L/ha before GS 30 may be beneficial for any crops with lower plant counts. This is to encourage tiller survival (not to reduce lodging), can give a yield response and also helps to even up crops. This PGR can be applied with the first fungicide. Use Moddus/Medax Max plus 1.0L/ha CCC for high lodging risk fields at GS 30. For best straw shortening effect in barley, apply Cerone/Terpal/Moddus / Medax Max from GS 32-39.
Broad leaved weed control should be based on sulfonylurea combined with suitable partner eg. Zypar/Galaxy/Hurler etc. Active growth and high rates are needed to control overwintered weeds.
Winter wheat - Nitrogen
Apply 40 - 50 kg/ha of N as the first split in mid-March. Increase rates to 75 kg/ha for thin crops, second wheat or where take-all is a risk. Generally divide the nitrogen applications ¼:½:¼ over three splits. Apply the main split by GS 31 and the last split by GS 39.
Where grass weeds are present Pacifica Plus/Monolith + Biopower are options. Broadway Star + Torpedo is a strong brome option where annual meadow grass has already been controlled. Avoid crops under stress and be careful of tank mixes. Where no grass weeds are present a spring type option like Ally Max, Calibre, etc., plus Galaxy/Zypar/Hurler etc. for wider weed spectrum.
Spring barley – Seed Rates
Seed rate should be calculated based on the Thousand Grain Weight (TGW) which is printed on the bag. Sow 350 seeds/m² to establish 300 seeds/m² in good conditions. Be realistic about establishment percentage and adjust the seeding rate for soil conditions. Teagasc research across three seasons (2011 - 2013), showed that the average establishment rate was 78%.
Straw Chopping Scheme
The DAFM has secured a dedicated €10 million for a pilot scheme on straw incorporation for 2021. While the finer details are to be confirmed (at time of writing) it is expected the measure will cover the chopping and incorporation of cereal straw namely oats, wheat, rye and barley. Oilseed rape is also being considered.
While the Measure is awaiting approval in Brussels, rates have been reported of €250/ha for cereal straw (with a reduced rate for oilseed rape) where farmers chop and incorporate straw as soon as possible after the harvest. Farmers will nominate parcels on their BPS application for the scheme.
All nitrates derogation farmer applicants must have an updated Nutrient Management Plan as part of the 2021 Derogation application. Your advisor or consultant must provide you with this as part of the planning process. This plan tells you the total amount of chemical Nitrogen and Phosphorus that you are allowed to spread during 2021. It also gives you a liming plan that outlines the total tonnage of lime that must be spread in 20121 and what paddocks or fields on your farm it is to be spread.
Please note that farmers applying for a nitrates derogation must spread a minimum of 25% of the total lime requirement each year. Apart from the regulatory reasons, liming the land makes good agronomy sense. By getting your soil pH to 6.2-6.3, you are getting a greater “bang for your buck” with the slurry and bag fertiliser that you apply.
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