Willow Air pilot James Allan drops a mixture of lime and super 10 phosphate from a Fletcher plane on to Landcorp's Waitepeka Farm, on the Owaka Highway. Photo by Rachel Taylor.

Waitepeka Farm is about 1000ha, and farm manager for the past 12 years Peter Gilder said this was the annual maintenance fertilisation.

After assessing the site with a GPS system, the pilot was able to drop only on the paddocks that needed fertilising.

"The process is prettyaccurate," Mr Gilder said.

"He is able to stop at one fence and start at the next one."

The fertiliser fell straight down on to the site where it was needed, and there was no drift.