Autumn fertiliser recharges the soil after a long growing season and sets the farm up for the year ahead. Your soil underpins every part of the business—pasture growth, animal performance, and profitability. With autumn fertiliser being one of your largest annual input costs, it pays to be clear about what you want to achieve before spreading any product. So, keeping your soil chemical fertility on track is an investment rather than an expense.
Autumn fertiliser falls into three categories:
Maintenance fertiliser replaces nutrients lost through product removal and natural soil processes, while keeping soil tests steady year-on-year.
Capital fertiliser lifts soil chemical fertility levels when tests are below target. This applies nutrients on top of your existing maintenance fertiliser to gradually increase soil reserves.
Strategic fertiliser drives short-term pasture growth at key times, such as autumn or early winter, when extra feed is needed.
When farmers talk about maintenance or capital programmes, they usually are referring to Phosphorus (P), Potassium (K), and Magnesium (Mg). These nutrients are typically less mobile in the soil and can be built up or maintained over time.
Nitrogen (N) and Sulphur (S) behave differently. Although essential, both are very mobile in the soil and prone to leaching. N primarily exists in organic forms which, unfortunately, plants cannot access. The small mineral portion they can access is often limited. Because these plant available nutrients cannot be stored effectively in the soil, they are best used strategically to give short, sharp boosts for pasture growth rather than as long-term capital inputs.
Another key question is whether to soil test. The answer is almost always ‘yes.’ If you cannot measure chemical fertility, you cannot manage it. Soil testing is a small cost compared to overall fertiliser spend and provides the confidence of making better, informed decisions. It allows you to track trends, assess previous applications, and target nutrients where they are needed.
Effective autumn fertiliser programmes give your operation clarity and purpose. By utilising soil tests, you will understand which nutrients can be built up versus those used tactically to match applications to your farm goals.
TECH TIPS
- Herbage testing of lucerne can identify potential micronutrients issues such as Molybdenum deficiencies, which cannot be detected by
soil testing. - When walking paddocks to be put into spring sown crops, dig a hole in the soil (20 to 30 cm deep) and look for signs of compaction. If compaction is identified, then ripping helps improve future crop yield.
