Fine-tuning conditions ahead of silage-making
01 June 2023
Taking account of field conditions ahead of silage-making is vital in order to maximise quality.
Second cut presents different conditions to first cut, as the grass is more fibrous and lignified and days are longer, meaning grass will dry more quickly.
Peter Smith of Volac suggests farmers need to bear this in mind when deciding on wilt times:
Second cut grass is inherently drier, so a 24-hour wilt is often excessive. Unless the weather is wet it may be possible to pick up grass on the same day.
If using a contractor, they will be able to provide feedback on their experience of optimum wilting times this season.
If filling on top of first cut, always place a layer of fresh grass before travelling on the silage, as otherwise carbon dioxide will be displaced from the silage already in the clamp and oxygen will move in.
Clamps should be filled in layers no deeper than 150mm and each layer rolled before adding another.
Once the last layer has been rolled, it is important to place the sheet on as soon as possible and fully seal the clamp to prevent any oxygen entering.
Krones Eleazar McKeever urges farmers to take time to check mowers, tedders and rakes are correctly adjusted to conditions on the day.
He says: It is vital to select the right speed on the mower conditioner.
For heavy crops, the higher speed of 900rpm is appropriate, whereas for lighter crops, the grass will need less conditioning.
There are seven settings for the distance between the baffle plate and top of the mower. For drier crops, choose a higher setting to maintain a greater distance for less conditioning and, for wetter crops, a lower setting will result in more bruising of the grass, leading to a quicker wilt.
Avoid closing it up too much as this can lead to excessive power consumption and increased fuel usage.
Setting the correct top link length to set the pitch of the blades will determine the length of stubble left in the ground. If mowing when the ground is soft, leaving a longer stubble length is desirable to prevent contamination.
Mr McKeever says tines on the tedder should be set with around 20mm tine tip to stubble to avoid them scraping the ground.
He says: The pitch of each tine on Krone machines can be adjusted individually by altering the angle of the wheel between 13-degrees and 19- degrees. For wet, heavy crops or when making hay, a low setting will spread the grass out as far as possible; for lighter crops or for repeat tedding of a hay crop, a higher setting is recommended.
The pto speed for a tedder should be no faster than 450rpm and ideally between 350 and 400rpm with the higher revs reserved for heavier crops.
If first cut yields are disappointingor quality is below expectations,this often indicates weed grasses areout-competing sown species and areseed might be the best option, JohnSpence of Limagrain UK says.
After the 2022 drought followed by a late spring, many farmers need more grass this season. Ploughing a field up now will mean taking a hit to production when grass growth is at its peak.
A preferred option could be to boost production from existing swards by over-sowing with more productive, fast-growing ryegrasses and introducing clover species.
Alternatively, some farmers may wish to hold off reseeding until autumn, or sow a break crop, such as stubble turnips or kale, to provide an autumn winter forage before reseeding with grass.
Spring or autumn reseed?
- Wider window of good conditions for establishment
- No heading in first season
- Better opportunity to out-compete weeds
- Minimal impact on yield loss
- Seedbed has time to settle over the winter
- Gives the option of growing an intervening cover or catch crop to help control pests and diseases
- Loss of peak grass growth
- Shorter window for soil to settle before carrying stock
- Weed competition can be significant with late reseeds
- Narrower window of suitable establishment conditions
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