By Natalie Wood, Yara Country Arable Agronomist
Micronutrients are a key part of a plant’s requirement for growth and ultimately yield. The term ‘micro’ doesn’t mean that these nutrients are any less important, just that they are required by the plant in smaller quantities. Remember that once you can see the deficiency symptoms it is often too late to rectify them; which is why routine tissue testing is important.
Looking back at spring 2019 tissue samples sent in to Yara Analytical Services, there are deficiency trends across the UK of certain nutrients, not only micronutrients but also secondary nutrients.
If we start with magnesium, which is a secondary nutrient, then 67% of samples sent in were in deficient categories. Magnesium is a key component of chlorophyll therefore it is important for light interception and energy production within the plant. If the levels of magnesium are insufficient the plant won’t be working at its full photosynthetic potential and so plant development, and ultimately yield, will be affected.
Boron is another nutrient that is showing as very deficient around the country, with 91% of samples received being in the red. Boron is particularly important for flowering and pollination, if the plant isn’t getting enough it can lead to poor grain set and therefore lower yield. Because boron is immobile in the plant it is important to ensure there is sufficient supply at those key timings to prevent any potential yield loss.
Finally, the third nutrient that appears to be deficient all around the country is zinc with 76% of samples below guideline levels. Zinc is important for increasing fertility which means the number of grains per ear – which in turn leads to increased yield and also a better quality yield.
If we look at which samples had Mg, B and Zn deficiency together then it is 76% of the samples received in 2019. This means that ¾ of samples sent in were deficient in all three of these key nutrients! Depending on when you are reading this there may still be time to apply foliar sprays to rectify them but if not then this could be food for thought when thinking about next season’s nutrient plans.