When fast, high-quality feed is needed, over-sowing existing pastures can be an effective alternative to full pasture renovation.
Over-sowing is the practice of drilling in new pasture seed over the top of rundown pasture to improve the performance of the stand.
“Benefits of over-sowing include increasing the useful life of a pasture, improved turn-around time from sowing to grazing and the reduced chance of winter pugging,” territory manager at Heritage Seeds Emma McDonald said.
“Over-sowing can be a good way to boost the productivity of your pasture base. This is especially important when fodder prices are high and the output potential of your pasture can be improved.” According to Ms McDonald, there are a number of key factors to consider when implementing an over-sowing program.
“One of the first steps is to address any soil fertility issues and to control the presence of existing weeds or pests. If the pasture is relatively grass weed-free and has a cover between 30-70 per cent viable ryegrasses, then the paddock is suitable for over-sowing,” Ms McDonald said.
The removal of unwanted residual pasture should also occur. This can be done by grazing the paddock down or consider using a knockdown herbicide like paraquat.
The second consideration is choosing a species that will match the maturity of the existing pasture. This is so you can optimise the quality and timing of both grazing and silage cutting later in the season.
“For existing stands of late-maturity perennial ryegrass, good over-sowing varieties include Hogan annual ryegrass for stands of 30-50 per cent cover,” Ms McDonald said.
“An Italian ryegrass such as Tempo or Aston or Shogun hybrid ryegrass is recommended for stands with between 50-70 per cent cover. If you have above 70 per cent cover, you may want to top-up with perennial ryegrass.”
“Timing is critical – sow as soon as possible after the break, or if you’re confident of impending rainfall, dry sowing may be an option too,” Ms McDonald said.
“Ensure your machine doesn’t sow too deep – aim for 5-15 millimetre for ryegrass. Apply adequate starter fertiliser and ensure fertility is corrected prior to sowing.”
nce the new pasture has been sown, grazing should not occur until it is sufficiently well established.
“Don’t graze too early. Wait until the new plants are well anchored. Time to first graze will be dependent on growing conditions, anywhere from six to 10 weeks,” Ms McDonald said.