Grains
Sustainability
Publication date
01 Jul 2014
Publication partner
This publication was supported by the Grains Research and Development Corporation and FAR Australia.
LEARN ABOUT ROW SPACING FOR WHEAT AND CANOLA ROTATIONS IN THE RIVERINE PLAINS
The Improved water use efficiency (WUE) in no-till stubble retained systems project was initiated as a response to Riverine Plains members’ interest in the influence of row spacing and drill openers within the region.
The project addressed questions including:
- What are the yield effects of row spacing in our region?
- How does row spacing influence nitrogen and WUE?
- Is there different optimum row spacing with crops of different yield potential and in different parts of the rotation?
Key messages
Through a series of trials, the project found that:
- Increasing row spacing in both first and second wheat crops decreased grain yields.
- In first wheat crops, there was some evidence the yield loss associated with wider rows was greater in trials where yields were higher.
- In second wheat crops, the influence of row spacing on yield was smaller and not always significant.
- The effect of row spacing on canola yield was highly variable in this project. When results from the four years of canola trials were analysed together, there were no significant yield differences in yield due to row spacing. However, there were significant effects in individual years.
- Different row spacings in canola produced different harvest indices (proportion of plant biomass harvested as grain), with wider row spacings producing less biomass but yielding the same as narrow row spacings.
- The narrow row spacing (22.5cm) was significantly more water efficient when compared to the wider row spacings (30cm & 37.5cm) in first and second wheat.
- Row spacing produced no significant difference in the WUE of canola crops.
- There was no effect of drill opener on yield of first or second wheat crops when analysed across trial years.
- Canola yields were significantly higher with the disc opener.
- The yield disadvantage associated with wider rows could be partially overcome by ensuring that reduced plant establishment (a common feature of sowing in wider rows) is compensated for with higher seed rates.
- Wider rows reduce the ability of the crop to intercept maximum sunlight per unit area. This reduces dry matter production, which is reflected in decreased tillering and head numbers.
- There was no evidence that the grain yield of wider-row-spaced crops could be improved with specific nitrogen timings in relation to narrow-row-spaced crops.
Learn more about our work investigating row spacing, nitrogen and water use efficiency in the Riverine Plains.