Reminder of precautions to be taken:
- Established plant cover should be sufficiently eliminated before renovation in order to limit problems of competition and allelopathic effects of creeping bentgrass (grass that diffuses anti-germination substances preventing plants around it from developing).
The different brands then presented their material. Out of 4 seed drills, 3 were direct seeding machines. The KUHN ESPRO was the only multi-purpose min-till seed drill.
Discs were not to be used in this exercise, and the versatility of the ESPRO seed drill with its modular design made it possible to use the coulter bar only. The terminal or joystick was used to simply raise the discs from work position.
After the presentation of the seed drills, tests were carried out. Each seed drill had to sow a plot in 3 different seeding conditions:
- a grazed strip.
- Opt for quick germinating species (RGI, RGH, RGA, Clover…) and aggressive and dominant varieties.
- Use spot starter fertiliser when seeding.
- Remain vigilant to slugs attacking seeds and seedlings.
- Avoid deep seeding (1 cm maximum).
- Seed in warm ground to optimise emergence speed.
- Analyse the reasons why the grassland deteriorated: lack of or not enough rotational grazing, overgrazing, soil acidity, drought, deficient or unbalanced fertilisation…
- a strip pre-treated with glyphosate, 10 days with the seedlings to destroy the plant cover.
Seeding quality of the different seed drills was observed during the test. Despite the fact that the ESPRO is not a direct seeding machine, it performed very good quality seeding. The ESPRO is in fact very well adapted to seeding for grassland renovation. The CROSSFLEX coulter bar and its double discs offset by 41 mm produce very high quality penetration, despite the lower pressure in relation to 100% direct seeding machines. The offset discs and reduced spacing also limit soil expansion. The press wheel enhances soil/seed contact and closes the furrow. Another important point for the rejuvenation of grasslands: Coulter pressure and depth can be adjusted separately. It is therefore possible to increase the pressure of the seeding units for effective penetration while retaining a shallow seeding depth (1 cm).
After having carried out tests with different seed drills, the Chamber of Agriculture also tested seeding with different seed mixes:
- a strip cut right down to slow down growth of the plant cover in place.
- Mix 1: 5kg/ha chicory + 5 kg/ha alsike clover
The KUHN ESPRO was chosen to sow the different mixes.
The test was carried out in September. It was heavily penalised by the drought that continued until October. It was not possible to draw conclusions concerning emergence, except that emergence was better on the strip where the grassland had been treated with glyphosate.
Other finding: establishment of plantain and chicory was better than the other seeds.
- Mix 2: 5 kg/ha plantain + 5 kg/ha alsike clover
- Mix 3: Timothy/fescue/ryegrass and -grass and white clover mixes