Kickstart your crops with new season nitrogen

EXPERT VIEW

Getting the best from nitrogen will be especially important this season, says Natalie Wood.

A wet autumn and a range of drilling dates mean nitrogen applications need careful consideration this spring.

The first nitrogen application is particularly important in cereals because it affects yield potential. In wheat, for example, tillering tends to start in the autumn when the crops are at the three to four leaf stage.

During the tillering phase, the maximum number of potential florets is set. Applying sufficient nitrogen before the third week of March can help increase the number of tillers the crop puts on, meaning a higher yield potential overall.

Variable conditions

As is often the case, unpredictable weather conditions mean that while some farmers are looking forward with their planning, some are behind schedule.

While some areas of the UK had average or below average rainfall during autumn, many areas south of the Midlands had almost 200% of the totals they’d usually expect. This resulted in a lot of variation in both drilling dates and growth stages.

The warmer temperatures seen up until the cold snap in early January may have benefits in terms of increased soil mineralisation. But it’s likely that many soils will still be deficient in nitrogen because of last year’s wet conditions.”

Farmers on track should aim for around 250 plants/m² in the spring, with first nitrogen applications adjusted according to plant population and growth stage. Crops on target with 250 plants/m² should receive about 60kgs of nitrogen.

So, the big question is: what should farmers be looking at in terms of products?

Presuming you’re going to need sulphur too, I’d recommend something like YaraBela Axan. If you want some phosphate and potash – good for most crops when spring soil temperatures are cold – look at a product like YaraMila 52S or Actyva S.

In the case of backward crops, they will need a bit more of a helping hand.

As there’s only a limited amount of time to increase the number of tillers and late drilled crops are already going to have fewer tillers, the focus should be on helping them with some early nitrogen – at a higher rate.

Time it right

Instead of 60kg/ha of nitrogen, farmers should look to apply 80kg or even slightly more depending on the situation. As well as an adequate amount of nitrogen, the timing of that first application is crucial too.

It should be applied as soon as possible once the crop is growing. If the crop isn’t growing, it won’t take up the nitrogen and there’s potential for nutrient loss.

To check the crop is growing, dig up some  plants and look at the roots. If the root tips are white, it’s growing. If they are grey or pink, or they’ve been in waterlogged conditions, the advice is to be patient.

If your cereals are particularly backwards, consider a split first nitrogen application. You might want to apply 40kg/ha followed by 40kg, but bear in mind that if the crop responds well you will need to get back in with the second application quite quickly.

Given that last year’s flooding not only damaged soil structure and washed away crops, but also depleted soils of micronutrients, farmers are encouraged to make use of them as well as phosphate and potash to kickstart growth and maintain momentum.

Informed decisions

Assessing the quality and status of soils doesn’t have to be guesswork. Yara has some helpful tools available, including soil analysis that can tell you everything from how many microorganisms are in the soil to whether pH is right.

Getting the pH right ensures more nutrients are available to the crop. Tissue analysis allows you to understand whether micronutrients are getting into the crop, and grain analysis enables better decisions about what you need to apply this season.

Yara’s digital Atfarm tool also helps farmers make more informed decisions about what to apply. It allows you to adjust nitrogen recommendations based on what the crops are telling you.

Grain analysis is a backward look, but you can compare what it tells you about the soil content with your most recent soil analysis to see how much you have lost in any flooding situation.

Natalie Wood is a Yara crop nutrition agronomist. For details, visit

www.yara.co.uk