Arable farmers are being encouraged to make early foliar phosphate applications to give crops a much-needed development boost this spring. Chris Bond, commercial technical manager at FMC, explains that the company’s crop tissue analysis from the last four years has shown that phosphate deficiency is an increasing problem across the country.

“This is partly because farmers have been cutting back soil applications of phosphate products in recent years, due to rising input prices and environmental concerns,” he says.

“If plants can’t access phosphate from the soil, then root growth and development, and subsequent access to other nutrients can be limited, which will affect yield potential.”

Mr Bond says that cutting back on phosphate is okay up to a point, but he urges farmers to be careful not to reduce levels of readily available phosphate in the soil.

“If you haven’t applied new, readily available phosphate, then root systems will struggle to access phosphate locked in the soil at this time of year. Phosphate is important for providing energy to plants, as it plays a role in the functioning of the ATP molecule, a key driver in energy production in plant cells,” he says.

“The relatively mild conditions so far this winter mean that many crops are well advanced. We hope this weather continues through March and April but there is still a risk of low temperatures. If we have a cold snap with low soil temperatures, it may mean that crops could be lacking in less mobile nutrients including phosphate.”

He adds that phosphate does not move easily in the soil, and its availability is reduced by cold soil temperatures.

“While crops will grow at soil temperatures as low as 5°C, phosphate availability at 10-12°C is only around a quarter of what it is at 20°C,” says Mr Bond.

With phosphate availability from the soil relatively low in the UK, there are multiple benefits of using foliar phosphate.

Foliar phosphate is immediately available to the plant, particularly at this time of year when crops resume active growth and start building biomass.

Mr Bond explains that applying foliar phosphate, such as Hi-Phos^®, ensures that the nutrient is available in the period between when plants begin more rapid spring growth and the point that soil temperatures rise enough to increase the availability of soil phosphate.

“It really helps crops produce a good root system and access nutrients from the soil. For best results, I’d recommend applications to coincide with tillering in cereals, or from early stem extension in oilseed rape,” he says.

“With a foliar application you’re only applying a relatively small amount of the total phosphate requirement and it cannot fully replace an application to the soil; but it fills an important gap for the crop when it may be struggling to extract enough phosphate from the soil due to cold soil conditions,” concludes Mr Bond.

To find out more about foliar phosphate visit https://fmc-agro.co.uk/crop-nutrition/hi-phos