Gloucestershire-based Emerald Research Ltd. (ERL) is the latest organisation to confirm the potential of foliar feeding crops.

In this case the focus is on phosphate – a plant nutrient that is fast diminishing as a resource that can be physically mined from the earth’s crust.

Approximately 70% of the world’s phosphate supply is controlled by four countries: China (39%); Morocco (17%); the US (10%); and Russia (6%).

With supply geographically limited, it leaves the market exposed to massive fluctuations in costs and supply due to political disputes, trade wars and escalating fuel prices. 

Since 2020, the prices of both phosphate rock and fertiliser have increased by around 400% and continue to rise.

Foliar feeding

Under the aegis of its Opti Yield brand, ERL is making the point that phosphate (P) fertiliser must be applied to crops in the most efficient way possible, hence the potential of applying the crop nutrient as a foliar feed.

According to ERL, broadcasting fertiliser is a shotgun application, spreading it far and wide in the hope some will reach its target.

P placed close to the seed at planting ensures it is within easy reach of newly formed roots to aid establishment from the start. 

However, the use of foliar application removes the scatter or shotgun approach to P/nutrient applications, delivering a predetermined dose directly to the crop leaves, making it available for use straight away.

This considerably reduces the amount of waste and, therefore, run-off into rivers.

The targeted approach to P applications relies heavily on the accuracy of the soil tests and data they provide along with the frequency of testing, providing yet another set of historic industry standards that need to be re-evaluated considering new learning. 

Liquid N

Meanwhile, the push to communicate the benefits of foliar feeding grass swards with a form of liquid nitrogen (N) continues apace.

Trials carried out at locations in Wales over a three-year period have confirmed that the application of foliar N to both grazing and silage swards can be increased by a factor of 300% and 200% respectively.

So, where an application of 250kg of N/ha was used with conventional fertiliser, similar yields could be achieved with 100kg of N/ha.

The work was carried out by Aberystwyth-based grassland consultant Nigel Howells.

Not only did his trial confirm the improved N-use-efficiency of a foliar applied nitrogen, it also pointed to an improvement in quality that can be achieved.

Benefits here include the significantly enhanced forage sugar levels that can be achieved by taking this approach.

The technology has been further refined by Co. Fermanagh-based Farmcare Products for Irish use in 2023.