Impacts of combining sunflower with perennial legumes
Impacts of combining sunflower with perennial legumes
Perennial legumes offer numerous agronomic advantages when combined with field crops. Demonstration on the Magellan-Terres Inovia GIEE partnership platform.
Perennial legumes (white or red clover, alfalfa or trefoil) can be introduced into plots in association with oilseed rape, meslin, intercropping cover crops, spring barley or sunflower. They provide soil cover, stimulate soil microbial activity, release nutrients and store organic matter.
Copyright : M. Geloen, Terres Inovia.
However, their control in cultivation must be carefully managed, otherwise you risk suffering severe yield losses!
This year, the GIEE Magellan has decided to dedicate a platform to the feasibility of combining sunflowers with perennial legumes in partnership with Terres Inovia (which has published a book) in the Nièvre region.
Several methods were tested:
- different legumes: white clover, alfalfa, trefoil,
- 2 sowing dates: with the sowing of sunflower and at the 5 F stage of sunflower.
The aim was to answer the following questions:
- Do perennial legumes have an impact on sunflower yield? If so, how?
- Is there a sowing time that is less damaging to sunflower?
- Do permanent cover crops have an effect on weed control?
In the end, legumes had a major impact on sunflower yields (by 10 to 15 q)! Delaying the sowing of legumes to the 5-6 F stage of the sunflower would limit the damage, but the dry conditions after sowing meant that the clover was not successfully established. This situation has recurred in recent years.
Legumes, and alfalfa in particular, have shown their ability to compete with weeds as long as soil cover exceeds 85%.
The trials will continue next year, diversifying the sowing dates and testing different varieties of clover and trefoil to assess their behaviour.
Contact : M. Geloen, m.geloen@terresinovia.fr