Done with cereals. What about the other crops?
04 Aug 2022

Done with cereals. What about the other crops?

Cereal fertilization done. Now what?

With foliar fertilizers from Flex Fertilizer System, you can fertilize your cereals, like wheat, barley, rye and oat, until around 14 days after flowering. Here in Denmark, that is typically the last week in june. So, should you put the fertilizer-sprayer away now?

If you have other crops, that keep growing for longer, it is not that time, just yet.

For instance potato-growers, will typically keep their starch-potatoes growing for another 2-3 months, and the dry weather during the summer, will often mean that nutrient-uptake can be quite difficult.

Not just nitrogen.

During a dry period, it is not just nitrogen, that the crops can become deficient of. Nutrients like phosphorus, potassium, magnesium, sulfur, boron and the micro metals, like manganese, zink and copper, can become very difficult for the plant to take up.

It is therefore a good idea, to keep an eye on your crops – or even better: to have leaf analysis sent in to check up on any latent deficiencies – you know: deficiencies that you can not see with the naked eye.


Our Danish producer, BJ-Agro has a lot of experience in spotting such deficiencies in potatoes, when analysing the newest fully developed leaf. And they have often been surprised, by what is actually missing.

In “the old days” it was always assumed, that it was nitrogen-deficiency that was holding back the plant, but now they know, that it can just as easily be one of the other nutrients. And the yield-losses in such cases can be quite substantial.

Correcting the deficiencies with foliar fertilizer is quite easy, once you know what to apply. So you should find a good and fast lab to work with, to get the data you need within a few days. In Denmark, BJ-Agro use OK-Lab. They are able to analyse the samples within a week. Other labs, like LMI in Sweden, can also be quite fast, if you use their standard-analysis packages.

It is important to use the same lab every time. Because the analysis methods are not always completely the same, and it is fine nuances in the analysis, that you are looking for, with such methods. And if you do decide to change labs, do the first couple of tests at both the old and the new lab. To see if you can spot any differences, and correct for them in your deficiency-limits.

Sugar beet.

Other crops that grow for a long time still, are for instance sugar beet. Even though sugar beet do  not require a lot of nitrogen, it does not mean that they have no nutrient needs.

Nutrient uptake will be affected in exactly the same way as potatoes, so applying a little foliar fertilizer during dry periods can be beneficial to keep the beets growing.

Setting levels for deficiencies can be a little more tricky, compared to potato, but do try to pick leaves of approx. the same size/developemental stage, when having them analysed.

There are, of course, also other crops. For instance, the Christmas Tree growers that we work with, typically start fertilization with foliars around now.

In any case, Flex Foliar products like N18+Ca+MgNS 18-2NPS 18-1-2, NK 18-3Foliar PhosphorusLeaf PotassiumLeaf Magnesium and the Micro Mixes, will help you reach the top potential of your crop.

When you use a foliar, remember:

– to add a surfactant, to lower the surface tension. E.g. 0,1% of Contact or Agropol often does the trick. To waxy plant-types like beets, it is very important.
– that a dry period means stressed plants. Therefore the plants may not tolerate the same amounts of fertilizer as you normally use during a non-stressed situation. So lower the level of fertilizer, especially if you are “spraying blind” without having actual measurements telling you what your crops deficiencies are. A good place to start is often to cut the normal dose in half.

Starter fertilizer

Maybe you are planning to have a winter cereal sown within a few months. In that case, you should consider placing a starter directly in the sowing groove of your wheat or barley.

Many farmers in Denmark use diammonium phosphate (DAP) mixed in with the sowing-seed. This will provide the crop with N and P. But maybe you should consider something with even more essential nutrients.

At Flex Fertilizer System, we have e.g. the Flex Basis NP 10-7 w S+Mg. This will provide the crop with not 2, but 4 essential nutrients in a plant-relevant ratio. You can also mix in some micros, e.g. our Multi-Micro, to give the crop a little Mn, Zn, Cu, B and Mo as well.

This will not only allow you to place more relevant nutrients with your seed, but also help you reduce the amount of nitrogen and phosphorus you use.

We have many different starters, depending on your crops needs etc. Do not hesitate to give us a call or send an e-mail, if you want to discuss what is the best option for you.



Borgeby Fältdager June 29th and 30th.

Tomorrow and thursday, we will  be at Borgeby Fältdager in Sweden.

See you in the future 🙂