Guideline for growers
- Accurate tractor guidance and stable implement tracking are key to successful inter-row sowing.
- Inter-row sowing improves handling of heavy stubbles and enhanced harvestability of pulse crops such as lentils.
- Timeliness of sowing, improved water infiltration and conservation, increased ability to retain stubble, reduced soil erosion, labor and input savings and lower take-all disease pressure are benefits of inter-row sowing.
- Implement tyne layout is important to avoid stubble blockages when off-tracking. Tine under-frame clearance of at least 500 mm is recommended.
Inter-row sowing and row spacing
In the Wimmera and Mallee row spacings are on average 12 inch or 30cm. Stubble flow improves and blockages are minimised when crops are sown at wider row spacings (30cm or 12 inch), particularly in heavier stubble loads. However research in WA has found that yield is reduced by one per cent for every inch the sowing row is widened beyond 18cm (7 inch).
Conversely, pulse yields can increase with wider row spacing. In chickpeas, yields and lowest pod height was higher in no-till, inter-row systems that used wider row spacings (30-60cm) compared with a 20cm conventional seeding system (Brand. J, 2011).
BCG sowing direction and row spacing research
A field trial was established at Jil Jil in 2015 to investigate the influence of sowing direction and row spacing on weed populations in the low rainfall zone.
Findings from the trial showed that crop emergence increased with wider row spacing but there was no interaction between row spacing and sowing direction. If the seeding rate is kept constant, wider row spacings will have a greater number of plants per row than narrower rows (Figure 1).
An increase in weed emergence per metre squared occurred with increased row spacing of 12 inch and 15 inch compared to the narrow row spacing of 9 inch. Again, there was no effect of sowing direction. If the seeding rate is kept constant, 9 inch row spacing enables greater crop competition with weeds (Figure 2).
For further information on row spacing in a no till system is available in the Flexible Farming Systems Factsheet and in Guideline No. 2: Row spacings for a retained stubble system in the Wimmera and Mallee.
Information on inter row sowing with disc seeders is available via the Inter row sowing with disc seeders in the Wimmera Mallee factsheet.
By De-Anne Ferrier, BCG
This research is being conducted by BCG as part of the GRDC Maintaining profitable farming systems with retained stubble initiative (project BWD00024 ‘Maintaining profitable farming systems with retained stubble in Victoria and Tasmania’).