Fertilising pastures – is it time to get back on the paddock?

Jo PowellsSenior Agricultural AdvisorPastures DRNSW South East Local Land Services

The well above average rainfall received in 2021 and 2022 has thrown many fertiliser plans into disarray. With paddocks waterlogged and too wet to traverse for most farm vehicles, spreading fertiliser has been out of the question for most land managers.

With paddocks now drying out over summer, trafficability has become less of a concern but high fertiliser prices may still cause some to balk at applying fertiliser. Many are questioning the need and value of applying fertiliser under current conditions, especially given the amount of residual pasture in paddocks. This article discusses some of the factors to consider before applying fertiliser in 2023.

What impact is fertiliser price having on my bottom line?

While global fertiliser prices have eased from the all-time highs seen last April/May (Figure 1), fertiliser prices remain very high and an ongoing cause of concern in agricultural production systems. In addition to high fertiliser prices, livestock prices have also continued to soften over the last 12 months. This begs the question - is there still value in applying fertiliser?

One way to assess the impact of fertiliser price is to construct a gross margin and adjust the fertiliser price to see what impact it has on the bottom line. Tables 1 and 2 are an example of a 2023 gross margin for a typical selfreplacing merino flock and a feeder steer breeding operation. In both gross margins we’ve used single superphosphate (SSP) as it is the most common and cost-effective way to apply phosphorus (P) and sulphur (S) – two key nutrients that are often most limiting in grazing systems.

Until recent years, SSP was quite stable and for a long period of time hovered around the $340 - $360/t mark (delivered on-farm excluding GST). So, for comparisons sake the first column in Tables 1 and 2 looks at the economics if SSP was sitting back