Are you feeding maize enough? 

Modern, high-yielding maize varieties can be very “hungry” for nutrients and trace elements throughout the season, yet crop demands are sometimes not being met, Cumbria-based agronomist Jim Clark and Hutchinsons’ crop nutrition manager Tim Kerr suggest. 

“I do believe that many growers are still underfeeding maize, and in dry years such as 2025, it can be particularly challenging to ensure crops take up enough nutrition from the soil alone,” said Mr Clark. 

Indeed, leaf testing at the Hutchinsons Carlisle maize trials site in late August last season showed issues with nitrogen, potash, and manganese, probably due to plants being unable to extract sufficient nutrients from dry soils, he noted. 

The risks of nutrient deficiency are often exacerbated in dry seasons; however, issues can – and do – still arise even when moisture is not limited, so nutritional programmes must be planned carefully to meet crop demands in every situation, he says. 

Mr Kerr added: “Traditionally, where maize is grown on mixed or predominantly livestock farms, nutritional demands are largely met with slurry or manure. However, depending on individual situations, you might well need to supplement these requirements, particularly if you’re growing maize in an arable situation.” 

Nutrient planning 

The importance of potash is often understated, commonly because the expectation is that applied manures will meet crop requirements, Mr Kerr continued. However, a high-yielding crop of maize will need 8 kg/ha per day during peak growth and will require in excess of 400 kg/ha in total in order to maintain yield potential. 

“It is therefore really important to ensure there is sufficient potash present and available to meet this demand.” 

Other macro- and micronutrients are important too; the three- to six-leaf stage is a key timing for nutrition to keep plants green and growing.  

“People are often putting herbicides and trace elements on at this timing. Leaf testing at this stage last year showed some crops were short of manganese, so this was included in applications. Some herbicides can be quite strong though, so growers need to check product compatibility and crop safety before adding other things to the tank. 

“Last season, some growers did go back with a separate application after applying herbicides, purely to apply trace elements to push maize on,” Mr Clark explained. 

Start strong 

Strong rooting is essential for maximising the ability of all crops to “mine” soil nutrients throughout the season, especially once maize gets beyond the stage where it is possible to travel through conventional machinery. 

Phosphate is particularly important in this respect, and trials over multiple years have shown clear benefits from applying placement P fertiliser, such as Primary-P, with seed at drilling, to help boost early root development and improve the crop’s ‘scavenging ability’ for water and nutrients throughout the season. 

In Hutchinsons Carlisle maize trials last year, across three varieties sown in the open and under film, freshweight yields were 5-6 t/ha greater where the placement fertiliser was used, while the uplift in dry matter yield was around 2 t/ha, worth the equivalent of £300/ha in extra value, said Mr Clark. 

“Given the favourable growing conditions in this area last season, the benefit perhaps wasn’t as big as we’ve seen in previous years, but it still more than paid for itself and is a far more efficient way of using nutrients than conventional DAP ‘down the spout’ applications.” 

A key issue with DAP is that although the soluble phosphate is initially readily available to plants, if it is not taken up by roots, it can quickly react with other nutrients in the soil, such as zinc, iron, calcium and magnesium, making it less available and causing localised deficiencies of those nutrients, Mr Kerr explained.  

“Protected phosphate products, such as Primary-P, are not as reactive, so remain available for longer.” 

He also dismissed suggestions that placing fertiliser close to seed could make plants “lazy rooters”. “Plants can recognise when there is sufficient nutrient supply, and providing there is, they will keep growing,” he added. 

READ MORE: Why fungicides still pay – even in tight margin seasons

Late nitrogen 

Early nitrogen demands in maize are relatively low, as over half is needed between the eight-leaf stage and tasselling, with a further third required during cob fill. 

Meeting this later demand is challenging, though, as crops can quickly become too tall for conventional machinery. During summer months, there is also more chance of dry conditions limiting plant uptake of granular nitrogen in dry soils and an increased risk of losses through volatilisation.  

In warm, biologically active soils, cycling of nitrogen can also occur more quickly, potentially further limiting the availability of N for plant uptake, Mr Kerr noted. 

This is where protected, slow-release methylene urea (MU) products can be more effective, he said.  “We’ve had many years of success with foliar-applied MU products in maize. They allow you to travel as late as you can through the crop but give a prolonged release of nitrogen over a six- to eight-week period.” 

Trials back up this approach, and the increased efficiency with which plants take up and use the nitrogen means that a single 20 litres/ha application delivering just 8kg N/ha is worth the equivalent of 40 kg N/ha of granular product. 

Anecdotal evidence from leaf testing at the Carlisle trials in 2025 also shows notable differences between crops that received prilled granular nitrogen versus fields where a slow-release foliar-protected urea product was used instead.  

“Tests showed more nitrogen in the leaf where liquid nitrogen was used, compared with the prilled N. That’s largely down to the dry weather reducing the crop’s ability to pick nitrogen up from the soil, but it’s something we’re going to look at more in 2026 trials,” Mr Clark said. 

Another area of interest is the use of foliar-applied biostimulants that use naturally occurring bacteria, such as methylobacterium symbioticum, to convert atmospheric nitrogen into ammonium for the plant, with some products promising to deliver 20-30 kg/ha of supplemental nitrogen.  

Bacteria enter the plant through stomata of young leaves before colonising surrounding leaves, stems and roots, where they fix nitrogen throughout the plant’s lifecycle. 

READ MORE: Hutchinsons event unveils latest developments in vegetable crop production

Look beyond nitrogen 

Mr Kerr reminds growers that the ability of plants to utilise nitrogen effectively depends on the availability of many other nutrients, such as zinc and manganese. 

“One way to get more from your nitrogen is to make sure all other nutrients and trace elements are there in sufficient quantity too.” 

Pre-season soil testing provides a useful overview of nutritional status, while in-season leaf testing can also give a valuable warning of potential deficiencies. 

“Remember too that soil conditions, such as pH, and seedbed quality can also influence nutrient availability; high pH and poor seedbeds increase the likelihood of manganese and potash deficiencies, for example,” the expert added. 

Applying late N by drone 

One of the biggest challenges to feeding maize later in the season is the height of the crop preventing the use of standard farm machinery.  

At the 2026 Carlisle maize trials, Mr Clark plans to investigate whether a drone can be used to accurately apply late foliar nitrogen fertiliser instead of a traditional wheeled spreader or sprayer. This follows successful trials of drone-based undersowing of grass seed into standing maize during the 2025 trials. 

“It’s probably not something you’d do over large areas of maize, but it could be a useful backup plan should you miss the opportunity to apply nutrients due to the weather, wet ground conditions, and/or rapid crop growth,” he noted. 

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