Grassland reseeding

Grassland reseeding is essential in rotational-based grazing systems. Find out how it can enhance productivity, soil health and forage quality.

Reseeding is not only used to refresh swards and add diversity; it also plays a critical role in improving the long-term sustainability of permanent pasture.

By introducing new species, particularly legumes, and optimising forage use, you can improve the overall efficiency of your grassland.

Well-managed grassland is the cheapest feed source for livestock, and it offers numerous economic and environmental benefits.

Improved grassland can yield over 12 t DM/ha in many regions of the UK, yet the current average is around 7 t DM/ha. This gap highlights the potential for improvement.

Increasing the area reseeded annually leads to greater grass production and better forage use, which, in turn, results in greater profitability.

Research from Irish dairy farms has shown that reseeding can significantly improve net profit per litre of milk produced.

Reseeding grassland offers numerous benefits, including:

• Increased grass yield and quality, which reduces reliance on purchased feed
• Legume integration, which not only adds nutritional value but also fixes nitrogen in the soil, reducing fertiliser requirements
• Helping address soil compaction, improving root penetration and water infiltration
• Reducing the presence of undesirable weeds, which compete with grass for nutrients and water
• Introducing new grass varieties with better productivity, durability and disease resistance
• Better fertiliser response as new grass varieties are often more nitrogen efficient

Typically, the benefits of reseeding can last between five and ten years, but they may begin to diminish over time.

The rate of decline and the need for reseeding will depend on factors such as:

Crop nutrition: Regularly maintaining the correct levels of nitrogen, phosphate, potash and sulphur ensures continued sward health.

Soil health: Maintaining optimal soil pH, managing compaction and ensuring good drainage are essential.

Weed control: An effective weed control programme helps prevent unwanted species from reducing the overall quality of the sward.

Management: Actively managing the ingress of native grasses, such as meadow grass and creeping bent, which have lower nutritional value.

Assessing whether a reseed is necessary is a crucial step in grassland management.

Several indicators can suggest the need for reseeding, including poor grass yield, weed infestations, soil compaction or a decrease in animal performance.

To help you decide whether reseeding is needed, answer the following questions:

1. Is the grass producing enough dry matter?
• Yes – proceed with existing reseeding plan
• No – consider reseeding
2. Are there significant weed issues?
• Yes – reseeding may be beneficial
• No – proceed with maintenance and management
3. Is soil compaction affecting grass growth?
• Yes – reseed and address compaction
• No – continue monitoring soil health
4. Is livestock performance or health being compromised by poor pasture?
• Yes – reseed to improve pasture quality
• No – continue with current management practices

For reseeding to be successful, you need to prepare.

Test soil to determine nutrient levels, pH and potential soil compaction. Correcting these factors will create a more favourable environment for reseeding.

Decide whether to reseed in autumn or spring, based on your farm’s specific needs, weather conditions and soil fertility.

Choose the appropriate reseeding equipment and method, e.g. direct drilling, broadcasting or conventional sowing, to suit your soil type and farm layout.

Selecting the right grass species for reseeding is critical to maximise productivity, resilience and nutritional value.

When deciding which species to plant, consider factors such as:

Soil type: Different grass species perform better in specific soil conditions.

Climate: Consider the local climate, including rainfall and temperature, and choose species that will thrive in your region.

Livestock requirements: Some species are more suited for grazing, while others may be better for silage or hay production.

Species type: Diploid (two sets of chromosomes) or tetraploid (four sets of chromosomes) – tetraploid varieties often have better water retention and larger leaf structures, making them more palatable to livestock and better for grazing, while diploids typically offer greater disease resistance and persistence in the field.

Once you’ve selected the right species, it’s time to establish your reseed. This involves sowing the seed at the appropriate depth, ensuring good soil contact for germination and using the right technique for your soil conditions.

Seedbed preparation: Make sure the seedbed is firm and free of weeds. Consider shallow cultivation or rolling to ensure good seed-to-soil contact.

Sowing rates: Follow recommended sowing rates for your chosen species and farm type. Over-seeding can lead to competition, while under-seeding may result in insufficient cover.

Fertiliser application: Apply fertiliser according to soil test results, ensuring the grass has access to the necessary nutrients for healthy growth.

Once your reseed is established, ongoing management is essential to ensure long-term success.

Pest and disease management: Keep an eye on common pests and diseases that may affect young grass, such as leatherjackets, slugs and fungal infections.

Weed control: Monitor for the presence of weeds and take appropriate action to control them before they become problematic.

Tiller development: Observe the tiller development in the first season. Healthy tillers will lead to a denser, more productive sward in the following years.

Fertiliser and watering: Continue to monitor nutrient levels and ensure your reseeded grass receives adequate water during dry spells.