A new resource to improve the understanding of in-season nitrogen requirements of crops, has been collated through a collaborative project led by the University of Adelaide
With favourable seasonal conditions in the southern cropping region elevating the yield potential of this year’s winter crops, grain growers are eager to meet the nutrient demands of their crops to capture the potential on offer.
To support growers and advisers in understanding the in-season nitrogen (N) requirements of crops, the Grains Research and Development Corporation (GRDC) has published ‘A Nitrogen Reference Manual For The Southern Cropping Region ‘.
The manual is a comprehensive guide to understanding, managing and estimating N requirements from paddock to paddock and season to season.
The manual was collated by a team from the University of Adelaide, University of New England, the University of Melbourne and advisers as part of a GRDC-invested project. It outlines key N fertiliser decision points for cereal crops, including:
- Tillering – re-assess soil moisture and yield potential, check tiller number in relation to current estimate of yield potential, and apply N to increase tiller number if required;
- Stem elongation – re-assess soil moisture, tiller number and yield potential based on seasonal rainfall and outlook, apply fertiliser N if required to match potential yield and grain protein target;
- Booting – if yield potential has increased significantly, additional N may be needed to maintain desirable protein levels.
Project leader Associate Professor Matthew Denton, from the University of Adelaide’s School of Agriculture, Food and Wine, says it is important for growers to make proactive assessments in-season and add N if it is needed, especially in good seasons.
“Adjusting in-season inputs to the estimated yield potential helps minimise seasonal and economic risks,” Associate Professor Denton says.