Seeding equipment which delivers a blended mixture of fertiliser either all with the seed or all below has rung a few alarm bells among scientists and farmers, according to Rohan Rainbow.
Mr Rainbow of the SA Research and Development Institute heads the Operation FerTill project which, in large and small-scale trials in NSW, Victoria and SA, is investigating fertiliser placement issues.
He said that in trials to date:
- Banding all the phosphorus fertiliser below could reduce yield. Often, yields were higher when phosphorus was applied in the seed row or at least some was applied in a split-banded application compared to all phosphorus fertiliser with the nitrogen fertiliser.
- Applying nitrogen on the soil surface and then incorporating it had not been as effective in improving yield as either banding before seeding or in one-pass operations.
- Nutrients supplied to the crop need to be in balance. For example, a shortage of zinc has been a clear limiting factor in getting maximum yields from banded nitrogen and phosphorus.
Operation FerTill is a partnership between GRDC, SARDI, Pivot Ltd and Flexi-Coil Australia.
Contact: Mr Rohan Rainbow 08 8842 3900