There is a new approach to the application of fertiliser emerging and it is one that goes much further than just throwing prills of nitrogen (N), phosphorus, (P) and potassium (K) at the field in the hope that it will somehow be utilised by the plants rather than washed away.

What we see happening now is a greater appreciation of the soil as it is realised that far from being an inert mix of mineral and organic solids, it is a teaming biosphere that remains largely unexplored.

With the growing demand for sustainability, it may be argued that the key to more efficient use of inputs is to understand and how the micro fauna and flora use them, and what may be added to the soil in a bid to enhance the efficiency of nutrient use by plants.

All methods are not equal

The method of application may also be more critical than thought. The arguments over how slurry – a liquid fertiliser in its own right – is applied, are far from over as the attention has focused on nitrogen loss rather than soil health.

The science of soil dynamics is still in its infancy and has often been dismissed in the past as all muck and magic, an accusation that was often levelled at organic farmers, often by those with a manufactured rather than natural product to sell.

Slurry injection
Slurry injection may be considered the least wasteful of nitrogen but the effect on the soil microbes is poorly researched

Yet, this is a situation that is being challenged as organic farming sheds the traditional association with somewhat of Bohemian-type lifestyle and focuses on the biology of the soil rather than just its mineral components.

Up until recent years there was a great divide between conventional and organic farming, but that is closing as demand for organic food has increased, certainly in continental Europe.

Farmers have responded by filling that expanding niche.

Another approach by Omex

One company that is taking a much more holistic approach to fertiliser and how the soil actually works, is Omex of Kings Lynn in Norfolk.

Omex produces a range of liquid fertilisers and bio-stimulants for a wide variety of crops in a wide range of conditions for use throughout the world, but it is the fertilisers that are attracting attention in Ireland.

Two years ago Agriland took a look at one contractor, Seamus Lanergan, who provided a liquid fertiliser application service in Tipperary using using Omex products.

Seamus Lanergan in SAM sprayer
The application of liquid nitrogen fertiliser after silage was said to boost regrowth far quicker than solid urea

The partnership proved fruitful with Seamus reporting keen interest and an expanding demand for this method of application, and he has since purchased a larger self-propelled sprayer to cope.

The benefits of spraying

The benefits of liquid application are many according to both Omex and Seamus, the foremost one being accuracy of application.

Sprayers are designed to work with expensive chemicals that need to be placed exactly where they are required at the correct rate.

Taking that technology and using it to apply fertilisers would appear to be a logical step.

Sprayer nozzles
When spraying onto a freshly cut sward, the fertiliser can immediately get to work rather than awaiting the rain

This is precisely the great advantage of spraying a solution of nutrients onto the crop rather than whizzing it on by conventional spreader.

Despite the very best attempts of spreader manufacturers to achieve accuracy, by the very nature of the mechanism and the materials being spread, a true and dependable accuracy is unlikely to be achieved.

It is not just a question of the correct overlap either. There could a tendency among some for the prills to be thrown into the bottom of hedges and into watercourses, the first is just a waste while the second is frowned upon for environmental reasons.

High volume nozzle
Liquid fertiliser nozzles are designed to shoot a stream of the product onto the ground rather than cover the plant leaves

Solid fertilisers that are mixtures rather than compounds may also suffer lack of consistency in their distribution patterns as the mixtures can vary considerably in their handling properties, often from one bag to another.

Then there is the wind, both its strength and direction will affect how accurately the various nutrients will arrive over the area of the target crop.

Indeed, when thought about from this angle, often the question occurs as to why solids are used at all?

Omex plant in Ireland

The answer is many fold, tradition and ease of logistics being the two most obvious. To that it might be added that lack of availability was a determining factor although attempts were made in the UK back in the 1980s to popularise dissolving urea and spreading it as a solution.

This lack of availability is now being addressed by Omex which currently brings the liquid fertilisers in from the UK, a situation which is likely to change as the company has plans to build its own production site in Ireland.

Omex nozzles
Luke Thornton and Hannah Allen of Omex with the range of nozzles available from the company

Once the supply ramps up it will be a question of getting out there to convince more farmers of the benefits of liquid application and the expense of conversion should be no deterrent as all modern sprayers should be suitable for use.

There is though, the question of storage for large volume fully bunded tanks are required to hold the liquid back in the yard.

Omex is able to supply these in two sizes, 50,000L or 30,000L, either at cost, or for free if sufficient liquid is purchased each year.

All farms can benefit

The company believes that using a contractor is the best way to start, and having ones own tanks starts to become viable when treating 250-270ac for the small tank, or between 400ac and 450ac for the larger tank.

Sprayers in Yard
Omex suggests that a good used sprayer can be easily converted to fertiliser application simply by changing the nozzles

Yet that is not the whole story, for there are savings to made in the easing of the handling of the material.

Sprayers are filled by pumps rather than hanging a heavy bag over a spreader and then trying to cut it open.

Washing down afterwards is also quicker as the tank and pipes simply need to be flushed out, instead of being washed with a hose, never the favourite job on a farm.

Another bonus of using sprayers is that trace elements, fertiliser inhibitors and growth stimulators may also be added and applied with ease, which is where Omex has an ace up its sleeve with its knowledge and experience of secondary nutrients.