In 2016, Agriculture Victoria researcher Ashley Wallace conducted mid-row banding (MRB) trials in Victoria. These were part of the GRDC/Agriculture Victoria Regional Research Agronomist program.The trials compared MRB nitrogen fertiliser in-crop to other application methods. MRB is when fertiliser is applied in concentrated bands below the surface to every second inter-row. They found MRB could potentially improve yield and N use efficiency.
The trials were repeated in 2017 and showed more variable results. But the research indicated MRB in-crop offered many potential benefits. It consistently improved N use efficiency, particularly where N deficiency is high. It also showed the potential to increase grain protein.
Trials will continue in the Wimmera and Mallee during 2018. Researchers will compare different N fertiliser application methods at sowing, as well as in-crop. They will also compare liquid and granular N fertilisers. Previous trials mainly focussed on liquid application.
Researchers will also investigate different methods of MRB. They will compare using ultra-high pressure injection instead of a disc opener. It is hoped that this will help with stubble handling and narrow row spacings.
Advantages of MRB
The potential advantages from MRB N fertiliser include:
- Increased yield, protein and N use efficiency,
- Reduced N losses from volatilisation where N is applied below the soil surface,
- Reduced need for rainfall following application,
- High concentrations of ammonium, which may slow nitrification and reduce losses through denitrification and nitrate leaching, and
- Altering the placement of N to potentially reduce microbial tie-up of applied N.
Growers wanting to MRB N fertiliser in-crop will need to consider factors such as:
- The ability to accurately apply N inter-row at a given row spacing, stubble load or crop stage,
- The speed of operations,
- The capital cost and ongoing operating costs, and
- Unforeseen impacts such as increased weed germination following inter-row soil disturbance.
James Nuttall and Jasmine Marsh, Agriculture Victoria.
ExtensionAUS: MRB promising for in-crop nutrition