5 things you can’t afford to ignore when reseeding
Reseeding is a costly exercise and it can result in an outlay of approximately €250-350/ac to complete.
However, when done correctly, the added benefits of the rejuvenated swards – including increased growth, nitrogen efficiency and quality – can cover the costs associated with reseeding in just two years.
At a recent ICSA/Germinal reseeding demonstration, Teagasc’s David Webster gave farmers a run down of some of the important things to remember when reseeding.
1. Soil fertility
Webster, a Teagasc Drystock Advisor, highlighted the importance of soil fertility and urged farmers to pay close attention to the pH, phosphorous, and potassium levels, of the soil.
“If you don’t have the soil fertility levels right you are not going to grow grass,” he told those in attendance at the event in Tyrrellspass, Co. Westmeath.
Farmers should aim for a pH of 6.2-6.3, he said, to maximise the potential of the perennial ryegrass in the sward.
Teagasc research shows that applying lime to an acidic soil (pH 5.5) can release between 48-64 units of N/ha each year for several years.
2. Weed control
Reseeding presents an excellent opportunity to deal with problem grass weeds, such as docks, nettles and thistles, to name a few.
The Teagasc representative advised farmers to apply a post-emergence spray to reseeded swards. Applying such sprays can eliminate these weeds from the reseeded pasture.
Failure to control these weeds will raise the pressure on perennial ryegrass and clover seedlings, which will invariably reduce the quality of the sward in the long term.
One of the major benefits of reseeding during this time of year is the ability to apply a post-emergence herbicide spray.
The ability to spray autumn reseeds can be limited due to deteriorating soil conditions, thus making it difficult to eliminate weeds such as docks, nettles and thistles, from recently-established swards.
3. Silage – to cut or not to cut
Many farmers may be tempted to cut a recently reseeded sward for silage as it contains a higher proportion of better quality grasses.
But Webster was firm in his view that farmers should avoid doing so in the first 12 months after reseeding.
It is necessary to allow the reseeded sward to tiller, he said, and this can be achieved by grazing the sward at low covers with light livestock such as cattle or sheep.
The process of tillering is critical for successful sward establishment and it also helps reduce the space available for weeds to grow.
Webster also advised farmers to avoid poaching recently reseeded swards, both at first grazing and during the shoulders of the year.
“If you damage the reseed, it can be difficult for that sward to recover,” he said.
The reseeding method utilised can also dictate when livestock can be returned to the reseeded sward to graze, he said.
Typically the turnaround time on swards sown by min-till methods is quicker, he said, as less soil cultivation is practised and the seed bed remains quite firm.
5. Sowing method
The Teagasc representative also touched on some of the reseeding methods available to farmers, focusing specifically on the traditional plough-till-sow and min-till methods.
He said that min-till sowing methods tend to work best for stony ground, as very few stones are brought to the surface.
However, the traditional plough-till-sow method tends to work best when the field or paddock needs to be leveled after land reclamation work or drainage.