Field Research & Agronomy

Regans Ford 2017

‍To assess the most efficient way to allocate fertiliser spend on ryegrass-dominated pasture

For further details contact your local Area Manager or the Summit Research Team

There was a significant positive dry matter response to nitrogen but not to phosphorus and potassium.
Nitrogen applied at 57 kg/ha ($65 /ha) generated the highest dry matter and gross margin under these conditions.
For the most profitable N application, a balance between application when the requirement for extra feed is greatest and when growth conditions are more favourable need to be weighed against each other.
Feed quality impacts of N applications can also be beneficial.
$65 /ha spent on nitrogen was the only treatment to increase gross margin significantly from the nil treatment.
PK and NPK treatments followed a typical diminishing returns curve.
$50 /ha spent on nitrogen, phosphorus and potassium increased total dry matter by 350 kg/ha.
This resulted in a similar gross margin to the nil treatment but more importantly maintains soil nutrient levels for subsequent seasons.
As soil nutrient reserves are utilised, it is expected that the nil treatment would fall further behind in total dry matter and gross returns.
The results reaffirm that in a pasture situation, higher rates over smaller areas are likely to have a greater overall impact than low rates over a larger area.