The older a grass ley, the less productive ryegrass species it will have in it, and the less response you will get from any nitrogen applied.
Reseeding will ensure an increased yield, quality, and feed value, saving concentrate feed costs further down the line. So it is important to get reseeding right from the outset, to ensure the swards are established successfully and maximum productivity is achieved.
Read this handy reminder guide, put together by our grassland and forage crop product specialists, to make sure you’re fully prepared this year.
Understand soil composition
Grass establishment, and therefore reseeding or overseeding success, depends on soil type and nutrient status. Soil samples will determine the suitability of the fields for grass seed establishment and therefore whether additional inputs will be needed prior to drilling.
The ideal soil conditions prior to overseeding and reseeding are:
- pH levels between 6-6.5 – this can greatly influence the availability of nutrients within the soil profile
- Phosphorus and potassium levels at an index of two to make sure nutrients are readily available for root growth
When direct drilling grass seed, remember to check soil compaction first. Consider subsoiling if compaction levels are deeper than 23cm and aerating if levels are between 7-12cm to prevent root growth from being impeded. Click here for a soil structure scoring guide to assess soil compaction.
Choose your method
There are three main methods of reseeding:
- Ploughing – conventional cultivation
- Minimum cultivation (min till) – this involves desiccating old swards and lightly cultivating fields to create a fine, level seed bed
- Direct drilling – no cultivation involved, grass seed is drilled directly into an existing ley that has been desiccated, grazed and harrowed
Ploughing is ideal for burying trash to help reduce competition with the new ley.
Minimum cultivation is generally carried out on fields that don’t have a heavy weed burden that would compete with the newly sown seed, and on wet fields that would suffer from subsoil compaction if ploughed. This method also reduces the risk of run-off and the release of sequestered carbon when compared to ploughing.
Direct drilling is a quick, cost-effective method that can be used to reseed or overseed leys. However, when overseeding there is a risk the grass seed may not effectively establish if competing with the old sward.
Create the optimal seed bed
After soil sampling, seed bed preparation is the next crucial step to consider when reseeding fields.
The two most important points to remember when sowing grass seed are:
- Grass seed should be no more than 10mm below the surface for successfully germination
- Rolling is crucial for good seed to soil contact to ensure germination
If conventional methods of reseeding are used, existing swards should be desiccated and left for 14 days before being ploughed, cultivated and stone picked.
The soil may then need to be pressed or rolled to create a smooth fine, firm, and level seed bed. A ‘fluffy’ seed bed will cause the seed to sit too deep, resulting in poor germination.
Once the seeds have been sown, consider rolling the field again in the opposite direction to increase seed to soil contact.
If direct drilling or minimum tillage is the approach, consider using a one pass machine that prepares the seedbed and improves seed to soil contact. Always assess the soil profile for compaction and consider aeration or subsoiling if required.
Don’t forget, if you need advice on which grass seed drilling machinery to use you can speak to one of our machinery specialists.
Find your nearest depot here.
Carefully select grass varieties
Grass varieties should be carefully chosen depending on the grassland production system and their compatibility with the soil type.
When carrying out a reseed, consider the whole sward structure as the grass seed selected and sward density will determine the long-term viability of the established sward.
For example, diploid ryegrass varieties are robust and ensure good ground cover, with their competitive tillering providing good carrying capacity for livestock.
In the case of overseeding, the aim is to choose grass varieties which will compete with the current grasses during establishment, for example tetraploid perennial ryegrass, hybrid ryegrass, or Italian ryegrass.
If reseeding or overseeding a drought-prone field, consider using deep rooted varieties such as Tall Fescues, Timothy, or Cocksfoot. Deep rooted grasses will also generally tolerate heavier soil types that can often be colder or more prone to waterlogging.
Legumes such as white and red clover can be included in the grass mixture to increase protein content of the sward and fix nitrogen.
If you’re unsure about which mixture to select, our comprehensive Grass and Forage Seed Catalogue provides a full range of our high performing Mega Leys grass mixtures.
For your FREE Grass & Forage Seed Catalogue:
Ring: Forage Line on 0800 023 4416