9 April 2020
To benefit from higher grass yields in the long term, spring reseeds need a light grazing and careful management in their first 6 months. Start by doing a ‘pull test’ to establish whether seedlings have rooted properly and then use young calves to nip off leaves from 6 weeks after establishment. “The last thing you want to do is to graze and lift out seedlings,” says LIC consultant Sean Chubb. “You only want to take off the top 4 cm to encourage regrowth and tillering, so use calves because they won’t graze as low or as hard as older stock. There is no point in doing all that hard work if you then have to oversow next spring. “In their first year, new leys need preferential treatment: leave a residual growth of 5 cm, potentially graze less and then perhaps correct for this in autumn. Accepting less tonnage this year means you will be rewarded with better growth in future.” Using heavier livestock not only risks overgrazing and slowing regrowth, but also compaction where reseeding has involved a full seedbed preparation leaving a light, fluffy soil. When direct drilling into an established sward, however, cows can be used to do a light first grazing. After its first grazing, a new ley should be left to grow to 2.5–3 leaves and not be overgrazed. Leaving slightly higher covers avoids taking energy out of the plant: roots need to grow down and out, says Sean. “This is particularly important going into summer. New leys are more susceptible to drought and dying from overgrazing,” he points out, adding that a typical 10% of the platform reseeded each year is not a large enough area to affect measuring and software calculations.