Buckwheat for couch control: Final Report

Findings & recommendations

• Trial results and grower observations suggest that combining methods is most effective for controlling couch grass, with targeted early-spring cultivations before sowing buckwheat.
• Late sowing of buckwheat allows more time for cultivation and may influence couch survival in subsequent crops.
• Other fast-growing green manures, such as phacelia, may also partially suppress couch grass.
• Buckwheat performs better than bastard fallowing in wet conditions, as it does not require prolonged dry spells. In the wet 2019/2020 season, buckwheat proved superior to bastard fallowing by protecting soil structure, improving organic matter, and enhancing subsequent crop quality.
• Growers noted reduced labour and fuel use alongside soil benefits, making buckwheat a more reliable option. However, seed costs can be high and may not be offset short term, though long-term soil benefits may be significant.
• Buckwheat showed similar couch control to bastard fallowing but with fewer cultivations and less soil damage.
• Couch grass distribution is patchy, making assessment difficult; walk-over scoring may be more accurate.
• Possible allelopathic effects of buckwheat after incorporation need further research.
• Buckwheat is a useful tool, not a magic bullet, alongside good rotations and well-timed cultivations.