Arable growers should resist the temptation to reduce crop nutrients this spring, with trials data suggesting that the application of foliar nutrition can enhance winter wheat yields by more than 0.9t/ha. That is according to ProCam’s crop nutrition portfolio manager, Phil Burrell, who explains that applying the right nutrients at the right place and right time will be vital to ensuring this year’s crops reach their full potential.

“With last year’s sub-par yields making cashflow tight for many arable businesses, and

rising input costs and subdued commodity prices putting additional pressure on farm finances, there is a lot of talk about how and when to cut back on crop nutrition and disease control,” Phil explains.

“Experience suggests that foliar applied nutrients are amongst the first inputs to be omitted in lean years, but that is a false economy, especially as this year’s crops have come out of the winter with the potential to produce good yields.

“Instead of cutting back, wheat growers should protect and maintain crop biomass and yield potential, not only by applying an effective programme of fungicides to keep diseases such as septoria, rusts and mildew in check, but also by ensuring sufficient nutrients are available to allow crops to fight off disease and progress unhindered to a plentiful harvest,” Phil adds.

Trials carried out by ProCam have shown that winter wheat treated with fungicides and foliar applied nutrients during the stem extension phase will yield as much as 0.7t/ha more than a crop treated with fungicides alone.

“Similarly, crops which receive no fungicides and no foliar nutrition will yield 0.92t/ha less than a crop which receives no fungicide but does receive foliar nutrition at T1, T2 and T3,” Phil describes. “The proof of the value of foliar nutrients is therefore clearly evidenced, with healthy, well-fed crops producing better yields and higher profits.”

Phil explains that nitrogen, magnesium, potassium and sulphur are all important in terms of a crop’s ability to convert sunlight into yield and improve grain quality, while nutrients including boron, copper and zinc are critical in optimising grain set. He therefore encourages growers to think carefully before excluding any foliar nutrition applications.

“Wheat yield is driven by maximising the number of ears per metre square, and by the number and size of grains each ear produces. It therefore stands to reason that crops need to be fed at the growth stages that have the biggest impact on these factors. For that reason, crops must have access to the necessary macro- and micro-nutrients they require during stem extension and again when the crop’s main solar panel – the flag leaf – has fully emerged.”

Up to 60% of a crop’s yield is produced by the flag leaf (40%) and ear (20%), with leaf two contributing another 20% Phil adds. “So, it’s essential to keep both leaves and the ear as clean and disease free as possible. It is therefore understandable why we spend so much time, money and effort on applying fungicides at the correct rate and timing. But applying the right nutrients is arguably just as important.”

Foliar versus soil-applied nutrition

Compared to granular fertilisers, foliar applied products are faster-acting and less affected by climatic factors and soil condition. “Foliar products are absorbed more rapidly because they aren’t reliant on the soil-root interface which can be hampered by cold or dry conditions, and by a high or low soil pH which will result in nutrients being locked up,” Phil describes. “Foliar applications are therefore more reliable and can correct deficiencies, boost crop growth and offset the impact of stresses such as drought or disease more effectively.”

Phil reasons there’s only one reliable method when it comes to understanding which nutrients to apply. “Nutrient deficiencies can easily be missed as their effects often remain symptomless until after the crop has been damaged and its yield has been compromised. So, it’s important to be proactive to stay ahead of any problems.

“Soil sampling has its place, but a basic test will only indicate what’s in the soil, not what the plant needs or what is available to the crop. In contrast, tissue or sap analysis can accurately identify which nutrients the plant has already absorbed and is a reliable way of identifying any deficiencies which can then be remedied via foliar treatment.

“By investing a relatively modest amount in tissue testing and foliar nutrition, growers can ensure their crops remain as healthy as possible so that they go on to produce a harvest which really tests the capacity of their farm’s grain store,” Phil concludes.

For more information about crop nutrition, disease prevention and nutrient testing, visit ProCam.co.uk to find your nearest ProCam depot and agronomist.