Nutrient performance indicators (NPIs) are calculations you can do to assess how effective and efficient fertiliser applications have been. Underusing fertiliser limits crop yield and can draw down soil reserves. Unless building soil reserves, overuse is a waste of money, as excess nutrients can be lost and may cause environmental […]
Topic: best practice
Best practice crop nutrition seeks to make the most of your fertiliser budget and minimise environmental impact. The ‘Four Rs’ is a nutrient management framework that aims to match nutrient supply with crop needs.
The Four Rs
The four components of the framework are:
The RIGHT source fertiliser
At the RIGHT rate
Soil testing informs crop nutrition decisions. Collecting representative samples is the most important step in getting useful information.
Plan your soil sampling
Map non-uniform paddocks into zones. Base the zones on observed soil differences (or EM38 maps if available), and sample them separately.
Use a sampling plan within zones. Grids, zig zags and […]
Critical soil nutrient levels indicate whether a yield response to fertiliser is likely – or not. Their role is to help avoid unnecessary or uneconomic applications of fertiliser. Critical levels are used in interpreting soil test results to make fertiliser recommendations.
The critical level is the value required to achieve 90% […]