Reseeding is a significant investment on farm. It is important to measure grassland and plan carefully to deliver the maximum return.
It has long been considered a cost-effective tool in the grassland farmers’ armour at around €300/ac, with payback expected within two years.
At a recent reseeding demonstration staged by Glanbia Ireland, Mary McEvoy of Germinal advised farmers to ensure they get the maximum return on the Price Purchase Index (PPI) by selecting quality grass varieties to drive on grass yield and aid milk production for dairy cows.
“Choosing the grass seed mixture is crucially important, as what we sow today you want to last for the next eight to 10 years out on farm,” said the Germinal technical development manager.
The decision must be made based on whether it’s pasture that will be predominantly used for grazing or for silage, with factors to be taken into account including quality, sward density and dry matter productivity.
The seed mix must include both diploids and tetraploids to create a dense, high-quality sward. In addition, the combination of seeds must deliver for the key traits required.
“From a grazing mixture perspective the most important traits you need to focus on are seasonal yield,. Quality is obviously hugely important and persistency of the grass seed mixture as well,” she added.
Ensuring you are putting in good-quality mixtures is going to have a positive effect in terms of animal performance over that time-frame.
Dr. McEvoy pointed out that a one unit increase in quality will deliver about a quarter of a litre of milk more per cow per day. “Over a 100-cow herd that figure becomes quite significant, quite quickly,” she said.
The PPI shows a difference between the quality ranking of the top-performing grass seed Abergain at €56/ha/year and the bottom-ranked seed at minus €38/ha/year. This is a difference of €94/ha/year.
Method
There are three basic methods of reseeding – ploughing, discing or direct drill – and it is important that the chosen practice suits the farmland.
Glanbia Ireland’s Phil Meaney said there were a number of issues and common mistakes that should be taken into account with each method. With ploughing, many go too deep which lets too much air into the soil.
Meaney said attention must be paid at the rolling stage as this can rectify that issue if done correctly. “You need to be able to walk across it and not see your tracks behind you,” said Meaney, on freshly rolled ground.
With discing, attention must be paid to the speed of the tractor as patchy coverage can result where it is driven too fast on uneven ground.
Meaney then emphasised the importance of waiting for the opportunity to reseed, whether it is in spring or autumn, as a level of moisture after reseeding is key for delivering strong grass growth.
Soil health
Dr. Stan Lalor from Grassland Agro said good soil health was key to protect the investment in reseeding.
“A key point is that we invest in the soil that we are trying to grow the grass seed in, so we get the maximum possible return,” he said.
Analysis from Teagasc has found the majority of soils are below the target levels of around 6.3 for pH, and potassium (K) and phosphorus (P) levels of index 3.
However, there are some positive signs of overall improvement during soil samples taken over 2017 and 2018.
Currently, lime use nationally stands at around one million tonnes a year, which had increased by on average 211,000t/year since 2013, compared to the previous five years.
“Even low rate applications of granulated limes or lime conditioners or full-rate application of lime, where the pH is low, is very important for reseeding,” he said.
Dr. Lalor said P was very important for the germination of new swards and must be present at the correct levels in the seedbed.
Teagasc research has shown that soils with P index 3 will grow approximately 1.5t DM/ha/year more grass than soils with P index 1.
Further information
For more information, check out the Glanbia Grass Seed & Forage brochure here.
Additionally, you can contact your local Glanbia Ireland rep, branch or visit: www.glanbiaconnect.com.
