Getting the best from pastures in spring

Pasture growth is an on-farm driver for beef production. It’s important to understand the value of investing in pastures and the key components of pasture performance, to maximise high beef prices in the markets.

As an estimate, every extra kilogram of pasture grown on farm costs about 10 to 15 cents a kilogram of dry matter to produce. If approximately 10 kilograms of dry matter pasture (depending on quality) is needed to produce 1 kilogram of liveweight gain on cattle, that’s an investment of $1.50 in pasture costs for a return of $4.50 in liveweight, therefore could provide a good return on your investment.

There are many factors which influence pasture performance that are not within your control such as soil type, soil temperature and rainfall. The two components of pasture performance that are within your control are grazing management and soil fertility.

Grazing management

Grazing management in spring can be easy as there is generally plenty of pasture to utilise. Rotational grazing will reduce waste and keep the pasture in the vegetative state while avoiding pasture getting long and rank. Shortening the rotation, keeping more stock on the pastures with spring calving cows or buying more store cattle post-winter will also help keep the pastures responsive. By taking paddocks out of the rotation for silage and hay harvest allows more grazing pressure to be put onto the remaining paddocks, therefore helping to maintain pasture quality.

Soil fertility

Getting more pastures growing in spring and extending the shoulders of the season given the good returns in cattle prices will pay dividends, so strategic fertiliser applications are a must. Soil testing is essential to ensure that fertiliser is in balance and only applied based on what the soil requires, not an estimate and will save money by avoiding elements that are not needed. Ideally soil testing should be completed every three years at a minimum, in spring or autumn if soil moisture is adequate.

Seasonal conditions and soil type can play a big part in fertiliser needs. A wetter than normal winter can leach out some of the nitrogen, sulphur and potassium from the soil, and can be likely elements to replace. In this instance a phosphorus, potassium and sulphur (PKS) blend with added nitrogen would give good results.

Even if soils have not been overly wet in winter and spring, the added pasture growth from the good seasonal conditions would have pasture plants utilising more of the available fertiliser in the soil. Therefore, most soils in various Victorian localities would benefit from a spring application of fertiliser. Levels of phosphorus for improved pastures grazing beef cattle would be in the range of 15 to 20 mg/kg Olsen P, while non improved pastures or native pastures could run at 12 to 15 mg/kg Olsen P for ideal results. Potassium on sandy soils with a Colwell K of 150 to 180 mg/kg and heavier clay soils around the 200 mg/kg is recommended. Sulphur is often neglected and sometimes in low quantities in the high analysis blends, plus a small amount may have leached, so it could be worthwhile asking for extra sulphur. The results from a soil test analysis and discussion with a fertiliser representative will provide guidance on the best fertiliser blend to apply.