Over the last month, many farmers have taken the opportunity to get clover established on their farms, either through over-sowing or as part of a full reseed.
The latter is a much easier way of establishing clover, as these fields won’t be grazed for another few weeks at the earliest, by which time the clover will be hardy.
The key thing to remember when doing a full reseed is to use a clover-safe post-emergence weed spray.
The announcement of a derogation to use these clover-safe sprays is expected this week.
For those who over-sowed clover into established grassland, management is much trickier.
Clover will usually germinate after seven to 10 days in the ground and with fields being grazed every 15 to 20 days, there is a fair chance that some of these seedlings will get trampled.
This is to be expected and something that cannot be avoided. Most of these seedlings will recover after being walked on.
Some won’t, but nor do we need all seedlings to survive for the job to be a success.
The bigger issue is to make sure that the seedlings have light down to the base and this means that the cover of grass in the field should never get too high.
Grazing covers of around 1,000kg DM/ha for the first couple of rounds will help to prevent too much canopy closure blocking out the light.
Teagasc advice is to reduce nitrogen during this period, as a means of reducing grass growth and so reducing the risk of canopy closure.
Maintaining the discipline to graze these fields at low covers is not easy and when grass is growing quickly, it means you really need to be on the ball regarding timing of grazing.
Young seeds have a high demand for both phosphorus (P) and potassium (K) and because their roots are shallow and not well established, they will need P and K close to their roots; ie near the top of the soil.
Even though a field may have soil tested with high P and K, some additional P and K fertiliser may be required to feed the new seedlings.
Even well-established clover has a need for additional P and K over and above what the soil sample results say is in the field.
This is because clover has a shallow root system and needs fertiliser close to the surface. Clover is sensitive to soil pH and potash in particular.
At Teagasc Solohead research farm in Tipperary, a half bag/acre of 0:7:30 is applied on the clover paddocks two or three times per year with no nitrogen applied from April onwards.