Rate of application
The rate of fertiliser application for a particular situation should be based on the rate of nutrient required by the plants.
For example, suppose we have a product containing 46% nitrogen and the desired nitrogen application is 50 kg N/ha.
fertiliser rate (kg/ha) = 50 kg N/ha ÷ (46% N ÷ 100) = 50 kg N/ha ÷ 0.46 N = 109 kg product/ha
In determining nutrient rates to apply, consider:
- soil and plant tissue analysis results
- nutrient budget reports
- crop type, yield/quality/stocking rate targets
- the need for maintenance or capital applications (i.e. goals for soil fertility and production results from fertiliser. Is the land manager trying to maintain present soil fertility and productive performance or increase nutrient levels to support higher production or different pastures/crops?)
- water availability and expected future weather patterns
- local fertiliser trials and local land manager experience
- previous crop and fertiliser history on the site
- different LMU requirements
Any application of fertiliser should be made on the basis of required present and/or future production level. If calculated fertiliser application rates exceed crop uptake as suggested by nutrient budget results this should be recognised and managed accordingly through a nutrient management plan, to reduce losses and ensure production is not limited.