- Each tonne of grain contains about 3 kg of phosphorus.
- Maize trials in NZ have not shown an economic yield response to fertiliser P.
- Only an average of about 30-40% of fertiliser P applied is actually used by the crop receiving it. Only soil solution P is readily available to plants.
- Phosphorus retention accounts for the majority of fertiliser P lost from a system, An estimate of a soil's ability to retain P can be made by completing a P retention test.