Safe Planting Rates of Starter Fertiliser for Narrow Rows
Poor establishment of seed can occur when fertiliser is applied in direct contact with the seed at planting due to osmotic burn of high Nitrogen content fertilisers.
Row width is the critical factor with the wider the row spacing the greater the fertiliser concentration is along the row. This occurs as there are less row metres per hectare that the fertiliser is applied to increasing concentrations within the row.
These rates apply when good soil moisture is present at planting.
Note: These rates apply when fertiliser is applied in direct contact with seed for cereal crops. When fertiliser is spilt away from the seed there is no limitation on rates applied.
Variables:
1. Low soil moisture levels rates should be reduced
2. Very sandy soils rates should be reduced by 50%
3. High clay based soils rates can be increased by 30%
4. Fertiliser blends that contain Potassium have higher osmotic burn potential and rates should reduced by 50%
5. When air seeders are used higher rates may be possible as air application spreads the fertiliser wider in the row due to air pressure over conventional planters
6. Cotton and some legume crops are more sensitive and rates should be based on local advice
