Deep nitrogen testing for reliable yield and protein
Sampling to depth gives a true picture of the mineral nitrogen pool available to the crop. Most nitrogen in soil sits in organic forms and becomes plant available as microbes mineralise it. Measuring nitrate and ammonium down the profile tells you whether yield and protein targets are realistic at planned rates. GRDC
How far to go
For grains in our region, profiles commonly run to 60 cm in three layers. Sandy subsoils or history of leaching may justify deeper checks. Consistent layer depths improve interpretation year to year. GRDC
When to test
- Pre-plant to set the base rate
- Tillering for winter cereals if the season shifts or early growth differs from plan, which supports in-crop topdressing decisions and reduces loss risks. GRDC+1
Practical tips
- Avoid headlands and stock camps
- Combine 15 to 20 cores per zone
- Chill or ship samples promptly, especially for ammonium stability
- Record GPS for repeatability
Ask Dawson Ag for a deep N run and an in-season check timed to your program.
