- It is very important to measure the soil mineral N as it varied from 20 to 207 kg N/ha in these trials.
- The optimum N application increased yield by 50 to 60% in irrigated wheat but the response in dryland wheat was very variable.
- The optimum nitrogen use efficiency (NUE) was highest in irrigated feed wheat and lowest in dryland milling wheat.
- There is no economic benefit in applying N for protein in Conquest milling wheat if the N applied through stem elongation has maximised yield.
- Forecasting the N supply from mineralisation is an important area for further work.