In most cases, fertilizer is applied before or during seeding. For some crops, further applications may be required for the duration of the growing period. Different nutrients are applied at different times.
Phosphorus should be applied as close to seeding time as possible to minimise risk of phosphorus fixation (the soil binds the phosphorus tightly).
Nitrogen can be applied both before and after sowing, depending on crop needs and the effect of soil and season. Commonly, nitrogen is applied after sowing in sandier soil types to minimise its loss and inefficiency.
