The recent hike in fertiliser prices has confirmed to tillage farmers the need for precision spreading of every pickle of these critical crop nutrients.

In so doing, farmers will ensure that they get the best on the investment they have made.

The most recent Tillage Edge podcast investigated the role for Global Positioning System (GPS) fertiliser spreaders in this context.

Teagasc’s head of crops knowledge transfer, Michael Hennessy spoke to Topcon’s Craig England about the growing use of precision fertiliser-spreading technologies within Irish agriculture.

Precision spreading of fertiliser

The first issue discussed was that of turning on and off a GPS-controlled spreader across headlands.

England explained: “If the grower starts on the headlands and then moves into the centre of the field, the GPS can be set up to ensure that fertiliser spreading is switched off for those further occasions when the tractor and spreader enter the headlands.

“This can be achieved in multiple ways, depending on the spreader being used. Growers can start with single section control, which turns on and off the whole spreader.

“However, it is now possible to have up to 32 sections controls, all of which are GPS activated. Section control acts to reduce the amount of overlapping within a field.

“The benefits of this technology can be easily seen within a field, once a crop starts to grow.”

Retrofitting GPS technology?

According to the Topcon representative, it is very difficult to retrofit GPS control technologies onto a three-point linkage spreader.

“Retrofit work is possible with some trailed spreaders. Kits are available. But with any belt spreader, operators need access to a forward speed, a belt speed and a weight,” he explained.

“Weight cells are required in tandem with the weight. There is a lot of engineering required to bring all of this together.

“In fact, the ancillary engineering work would cost a lot more than the actual GPS kit itself. The mounting of the weight cells is a very complex procedure.”

While weight cells are not required on all GPS-controlled fertiliser equipment, Craig England did confirm that all high-end belt spreaders are running with this option.

He added: “Some three-point linkage spreaders are running on weight cells. Others, however, operate on the basis of the torque-related or twisting action of the disc.

“These pressure changes allow the software to calculate the amount of fertiliser leaving the spreader.”