Silage helps to manage seeds
From the March 2012 edition of Agriculture Today.
The fate of weed seeds incorporated in silage has been investigated.
Research has involved recovering weed seeds after they have being ensiled in chopped cereal silage for three months to determine germination and viability.
The research also looked at the viability of seeds after being in the rumen of cattle for 48 hours.
The weeds investigated included barley grass, brome grass, silvergrass, wild oats, Paterson’s curse, silverleaf nightshade, wild radish, wireweed, prairie ground cherry and marshmallow.
“Our research showed that almost all the weed seeds lost all viability after being stored in silage,” said Charles Sturt University weeds research officer Rex Stanton.
“The major exception was marshmallow seed, which after both digestion and ensiling still had more than 40 percent viability,” Dr Stanton said.
He and silage expert and NSW Department of Primary Industries livestock research officer John Piltz conducted their research through the EH Graham Centre.
They also found viability of seeds from most species was also reduced in the rumen after 48 hours, though the effect was less than ensiling.
Other notable results were that seed from two summer weeds, silverleaf nightshade and prairie ground cherry also survived the digestion process with little loss in viability.
Livestock could graze on mature berries in the field and potentially spread these weeds.
“Overall, silage was far more reliable for reducing weed seed viability than digestion in the rumen, and the combination of both processes had the biggest effect, destroying most seeds,” said Mr Piltz.
It is not yet fully understood what aspects of silage are critical for killing weed seeds.
Plans are underway for further research, which will include a wider range of weed seeds and silage types.