101 Questions answered
Nitrogen Efficiency Unaffected by Fertiliser Type in Calcareous Soils; Timing Matters
Not really. The fluid vs granules argument only applies to phosphorus. With other nutrients, there is more flexibility with the form it is applied. This is because calcareous soils do not lock up nitrogen to the same degree as they do with phosphorus.
Trials from 2017 – 2019 in the mid North and Mallee tested how well crops took up various nitrogen fertilisers (DAP, SoA, liquid UAN and urea) on calcareous soil. The type of fertiliser didn’t affect nitrogen use efficiency. However, these were dry years so researchers couldn’t see if this was still the case in a nitrogen-demanding season.
On calcareous soils in the Mallee, it is often ideal to provide the bulk of the nitrogen upfront and if applying nitrogen in season, do so before rain.
