Harvest management

The principles for ensiling lucerne are the same as for any other crop. Lucerne is a high protein feed with low carbohydrate levels and a higher buffering capacity. This means that a lot of acid must be produced to drop the pH, yet it is difficult for this to occur since carbohydrates (sugar substrate for the fermentation bacteria) are limited. For lucerne, extra care must be taken to wilt, harvest and store as quickly as possible. Using a quality silage inoculant will ensure that the limited amount of sugar available is efficiently converted to acid.

Table 6: Target drymatter content for ensiling lucerne13
  Stacked silage   Baled silage
Vegetative to early bloom
30 - 35% 35 - 50%

Wilt as quickly as possible. This can be achieved by using a mower conditioner and making the windrow wide and thin especially if the crop is dense. It is important that lucerne is not over-wilted, as the leaves as well as some of the nutrient value will be lost in the dust created by the harvesting equipment.

Wilt time will depend on the wind, humidity, heat and sun but is normally between 12 and 24 hours. The "squeeze test" can be used to help determine lucerne drymatter content.

To ensure good compaction, precision chop lucerne at 8 - 12mm.

13Producing high quality alfalfa silage requires paying attention to harvest maturity, wilt times and length of cut.
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