What is the most productive fertiliser you can use on your farm?

Our independent soil scientist at Shannon Agricultural Consulting has conducted experiments in both the glasshouse and in the field to establish which fertilisers produce the greatest pasture growth on a range of soils. Conducted by Paddy Shannon, these trials have come up with some interesting and sometimes surprising results…

Environmental Impact and Product Innovation

2017 - 2018 Trial

To get further understanding of why TerraCare Slow Release fertilisers grow more grass, a comprehensive trial has been designed and implemented. The Lysimeter trial at the TerraCare R&D center aims to assess the effect of our current products on the environment as well as provide information on product improvement.

The trial is supported by Callaghan Innovation: the governmental business innovation organisation



Lysimeter trial

Performance on different soils

The initial glasshouse trial compared pasture growth over a season on different soils fertilised with TerraCare rePlenish, TerraCare uPgrade, and a Superphosphate alongside an unfertilised control tray. 

The second trial compared pasture growth rates of different types of soil – Pallic, Volcanic and Raw Slip Face – each fertilised with a superphosphate, TerraCare rePlenish, and TerraCare uPgrade, alongside an unfertilised control tray.


In both trials rePlenish consistently produced the greatest pasture growth in the soils tested. 

  • On pallic soils, rePlenish produced 20% more pasture growth than Superphosphate.
  • In all cases each type of soil (Pallic, Volcanic and Raw Slip Face), grew more (>10%) dry matter when top-dressed with TerraCare rePlenish and uPgrade Dicalcic phosphate, than Superphosphate

A 3-year scientific field trial was then undertaken in Pirongia, Waikato comparing TerraCare rePlenish and uPgrade, with Superphosphate.

Greatest pasture growth

TerraCare rePlenish, TerraCare uPgrade and a Superphosphate fertiliser, were all trialled alongside each other at five varying rates to establish which fertiliser produced the greatest rate of pasture growth.

rePlenish fertiliser consistently produced at least 10% higher pasture growth rates than other phosphate fertilisers.

Overall Results

  • TerraCare rePlenish produced the greatest pasture growth in all the trials.
  • rePlenish consistently grows at least 10% more dry matter per year than Superphosphates.

During the phosphate response trials, I conducted for TerraCare Fertilisers Ltd, rePlenish increased pasture growth more than ordinary Superphosphate. If the measured increases in pasture growth were to be efficiently converted into animal production, the overall result would show that using rePlenish instead of Superphosphate will increase profits.

PW (Paddy) Shannon, Scientist

Talk to our TerraCare team today

If you want to find out more about the results you could get on your farm, talk to our TerraCare team today.