Agronomy Advice
March 28, 2023

Using foliar nutrition on Maize crops

Growing maize crops with good forage quality and high yields will be paramount this year, considering the increased costs associated with using biodegradable film or for those growing the crop without film, minimising the potential loss in yield associated with planting in the open.

Maize in a field
Maize in a field

Agronomically, there is a lot the farmer can do to protect and maximise their investment. These high yields of 40+ tonnes/ha can only be achieved if the crop can access enough nutrients via its roots, and leaves as the plant grows. The critical stage with respect to crop nutrition is when the crop reaches the V6 growth stage (6 leaf). As rapid plant development is about to start, it is important that the necessary nutrients are applied just before this stage to support this growth.

Do you know the roles of key nutrients in maize?

All nutrients have crucial roles in plants. Some crops have a higher requirement for certain nutrients and so deficiencies of these are more likely, however a deficiency of any macro or micronutrient will result in loss of yield and quality.

Zinc and magnesium deficiencies are the two most widespread nutritional disorders in maize. Zinc is important for photosynthetic activity. Magnesium is essential for the early establishment of the plant. A deficiency is reflected in reduced crop yield at harvest.

Phosphorus and potassium are primary nutrients, however many soils have not got the capacity to deliver an adequate supply. Where phosphorus availability is reduced because of soil pH or where its uptake is impaired due to dry soil conditions, foliar phosphorus will help. It is translocated from the leaf to the roots very effectively, maintaining root development.

One or more of the above is often deficient in the growing maize plant. This nutritional shortage is particularly important as the plant reaches the 4 to 6 leaf stage as it is now that yield is being set. Maize stressed at this point can result in tall, thin plants, with poor root systems and reduced leaf area. Reduced leaf area captures less light, resulting in lower yields.

Maize foliar nutrition

A Yara maize trial in Co Carlow last year, demonstrated the positive effect that combining foliar nutrition and biostimulants had on crop performance. In this trial the combination of our crop specific product for Maize - YaraVita CROP BOOST (5 L/ha) and the biostimulant - YaraVita Biotrac (2 L/ha) applied at the 5 leaf stage increased dry mater yields by 16%, which equated to an extra 2.5 tonnes of dry matter per hectare. YaraVita CROP BOOST is specifically formulated for foliar applications on maize, containing a high concentration of phosphorus, zinc, magnesium and potassium.

When applied together, YaraVita Biotrac complements the nutritional effects of YaraVita CROP BOOST. Thanks to the unique combination of selected bioactive components and nutrients, YaraVita Biotrac activates the plant’s metabolic processes to enhance nutrient use efficiency and tolerance to low temperatures. The two YaraVita products work in harmony to maximise the ability of YaraVita CROP BOOST to promote root and plant growth and efficiently use the plant’s energy reserves.

You may ask how do we know what are the key nutrients to include in these two crop specific products? The answer here again lies with research data and knowledge that has been conducted to identify them. Yara, through its research facilities in Pocklington, York, runs a screening process through nutrient specific trials to prioritise nutrients according to their impact on crop growth and development. Once these are established then crop-specific products can be formulated to deliver enough quantities of these specific nutrients.

The results of two years of maize trials conducted by Yara in both the UK and Ireland have demonstrated an economic justification of using YaraVita CROP BOOST and YaraVita Biotrac together. There is a very strong case to adopt the YaraVita Maize Programme at the 4 – 6 leaf stage to minimise the risk of nutrient deficiencies and abiotic stress in Maize and maximise yields.