2024 was certainly a tricky one from a clover incorporation point of view, as the weather and poor growing conditions hindered pasture growth on many farm across the country.
Clover swards were particularly affected with cooler soil and air temperatures affecting stolon proportion, which delayed clover contributions in the sward until late summer on many farms.
Clover favours warm, dry and bright growing conditions and when these are limiting factors, it significantly impacts the ability of clover to persist in swards.
In the spring of 2024, clover contents were back by 8% on previous years and chemical nitrogen (N) usage was increased which helped with the recovery of clover in the autumn.
Clover growth and persistence is going to vary from year to year especially with changing weather patterns and unpredictability in the weather.
However, it is important to put a plan in place for the year ahead to promote clover development and reseeding to ensure high clover performance in 2025.
At the end of the day, if you get your clover incorporation right, you will see a significant reduction in your chemical N use and will improve your farm gate N surplus.
Clover 2025
Ideally, farmers should have aimed for a light cover when it comes to clover paddocks to ensure the plants survival of the winter months, as they should of been the last paddocks to graze late in the final rotation.
By doing this, the paddocks will have low covers during winter months, which will allow light to continue to reach the bottom of the sward – keeping it alive for another season.
The more stolon that survives that winter, the higher the clover content of the sward which will lead to more N fixation the following season.
Soil fertility has to be at optimum levels for clover to persist which means that farmers should complete a full set of soil samples for the farm.
Clover depends on optimum levels of overall soil fertility and there needs to be clear focus yearly in the targeted application of phosphorus (P), potassium (K), and lime.
The soil fertility status in Ireland is sub-optimal as only 20% of dairy farms are optimal for P, K and pH, which will challenge the ability of farmers to establish and maintain the persistency of clover.
Clover requires soil indexes of three for P and K; it also requires a soil pH of 6.5. Potassium is a key nutrient in the plant structure development, root growth and plays a key role in the uptake of N.
Spring
Grass-clover paddocks need to be grazed early in the first rotation at covers of about 1,200kg dry matter (DM)/ha to get light to the base of the sward as soil temperatures are improving.
It is crucial to try and be flexible with your grazing plan as there is no point going into these swards and damaging the plant if conditions don’t suit.
Farmers should aim to apply 2,500gal/ac of dilute cattle slurry after grazing these paddocks as it will replenish the N, P and K in the sward and promote early pasture growth.
Farmers should identify which paddocks underperformed throughout the year and aim to reseed these paddocks with a high clover mix in April 2025.
Paddocks that are infested with weeds should also be considered for reseeding in April.
The aim should be to reseed 10% of the milking platform next April as reseeding is the most cost effective investments one can make on a farm.
Any swards that have a low clover content or where the plant is struggling to compete with grass or the plant has been damaged should be oversown with with clover in April as well.
A medium leaf white clover on the recommended list should be used using about 2-2.5kg/ac and aiming to sow 10-15% of your farm each year to ensure continued improvements in clover incorporation.