To investigate the effect of phosphorus application rates and strategies over a number of years on the growth and yield of wheat.

The value of starter P for early crop vigour was clearly demonstrated in 2014 by the decreased growth of wheat plants when P fertiliser was omitted. This effect continued through the grain development stages and was very evident in the final grain yield differences. If P application over the previous four years averaged 12 kg/ha or less, there is a good value return from applying P.  Although the highest yield was seen at 24 kg P applied in 2014, looking at historical trends shows that continual application of P at greater than 12kg/ha can provide yield gains but little or no margin and should not be considered unless low P application history, confirmed by soil P tests associated with P binding capacity, has resulted in low soil P levels. Results indicate a P recommendation of greater than 6 kg/ha to be appropriate for soils and conditions in the vicinity of the trial site, pushing up to 10-12 kg/ha if the input cost is affordable.