Drum Mower
When do mechanical losses occur?
Mechanical losses of Dry Matter (DM) occur at mowing and conditioning, and at each raking and tedding operation.
Figure 6.13 shows the level of DM loss that can be expected in lucerne harvest operations.
This study highlights that losses caused by raking or tedding increase with increasing DM content of the forage.
Raking into windrows should be carried out before the DM content reaches 50%.
Leaf shatter losses in lucerne and most other legumes may be four times greater after mowing, conditioning and tedding than for grass or cereal crops.
In the case of lucerne, there should be minimal mechanical treatments after mowing and conditioning, and preferably none, as even freshly mown crops suffer some leaf loss with tedding.
Conditioning with a roller-type conditioner to speed moisture loss from the stems is recommended. Lucerne leaves dry 3-5 times faster than the stems and quickly become brittle. Over-wilting of lucerne and other legumes should be avoided.
The leaf fraction of legumes remains on the plant in well-managed silage systems, even baled silage at 50% DM content. However, under extreme drying conditions, particularly in unconditioned crops, the leaf may become brittle at DM contents of 35% or less.
