Nitrogen timing crucial to yield and protein
Growers thinking of using late-season nitrogen loading to bolster crop protein should think again, following a detailed crop and economic analysis led by the Northern Grower Alliance (NGA).
Very low protein levels were recorded in the 2010 and 2011 winter crops, resulting in downgrading at receival and significantly reduced economic returns to growers.
As a result, a research project led by the NGA, a grower solutions group funded by the Grains Research and Development Corporation (GRDC), conducted trials in 2012 and 2013 to evaluate the impact of late nitrogen strategies on protein accumulation and the likelihood of economic benefit.
“The series of 11 trials showed that significant increases in protein can be gained by late nitrogen application, but the level of increase was not sufficient to deliver economic benefits in any trial,” NGA chief executive Richard Daniel said.
“In all trials, the late application timings started at full flag leaf emergence and continued fortnightly until early grain development. Foliar application was clearly the most effective method, while late application of spread urea was, as expected, the least effective method of applying nitrogen.
“These results suggest that trying to manipulate wheat protein with late nitrogen application is unlikely to be a very effective management tool in areas, particularly where spring rainfall is highly erratic.”
Mr Daniel said unless the efficiency of recovery of nitrogen in the grain could be increased dramatically, grain price differentials of ~$20-40/t would be necessary before even considering this type of approach.
“The application of that extra nitrogen earlier in the crop would have been a lower risk option, particularly in dryland situations,” he said.
“If we’re putting nitrogen on early we’ve got a good chance of getting a yield benefit as well as a protein kick. If we’re leaving it to the end of the season we basically eliminate getting a yield benefit out of it and all we’re relying on is getting a protein benefit, so we have all our eggs in one basket.”
Audio download: Download the audio file from the downloads box below to listen to Richard Daniel, CEO, Northern Grower Alliance, discussing nitrogen management in northern cereal crops.
Richard Daniel, CEO, Northern Grower Alliance
0428 657 782
GRDC Project Code NGA00003