Fertiliser strategy
A ‘year-round’ fertiliser strategy for broccoli grown on the sandy soils of the Swan Coastal Plain is shown in Figure 4.
This combines the methods outlined above with recommended rates and preferred products based on current research. Products, timing and rate recommendations may change with more research.
Figure 4 3Phase annual fertiliser strategy for broccoli according to planting date. Planting dates are shown at fortnightly intervals in some months to account for rapidly changing temperatures, rainfall and sunshine hours
Important notes
- Nitrophoska Blue Special® has been the most effective product for broadcast and banding in trials to date, from the perspectives of efficacy and labour saving. This fertiliser contains 12% nitrogen, 5.2% phosphorus and 14.1% potassium. Other equivalent compound (granular) fertiliser products with similar analysis may also be suitable but need to be tested.
- Broadcast or spray applications in Phase 1 can be applied once a week — at double rates — with no to small reductions in final yield when irrigation rates are low or heavy rainfall is not expected. Twice-weekly applications are recommended when rainfall is expected or irrigation requirements are high.
- If fertiliser in Phase 3 is applied by boomspray, fertiliser residue must be washed off the foliage to prevent fertiliser burn as higher rates of fertiliser are applied at this time compared to Phase 1.
- Urea may not always be a suitable source of nitrogen in Phase 3 in the coldest months as temperatures may be too low for its conversion into ammonium and nitrate.