The maximum application rate of fertiliser in the seed furrow is primarily influenced by the susceptibility of the crop species to ammonia and osmotic effects of the fertiliser, application equipment and soil conditions at planting and post planting.
Ongoing research by Incitec Pivot Fertilisers and data from Canadian and Australian research has provided the necessary information to significantly update recommendations for seed row fertiliser taking into account crop species, the chemistry of the fertiliser, soil conditions and application equipment.
Seed-bed utilisation percentage (SBU%) is a term that has been developed to describe the effect of row spacing and opener type on seed furrow fertiliser concentration. It is calculated as:
Some disc openers may have seed spreads less than 25mm. Worn points and discs can affect seed furrow width. Check seed and fertiliser spread in the field at sowing.
Click to download a pdf of the utilisation rates.