August Grass Management

By Mícheál Kelly, B&T Drystock Adviser, Teagasc Galway/Clare

Grass growth has been sporadic throughout 2024 but there seems to be an improved situation over the last few weeks. Many factors have been at play here including lower temperatures throughout the summer where we saw temperatures getting into the teens during the day and dropping back to single figures at night; harsh winds; lower levels of sunshine; soils recovering from poaching damage and compaction, not to mention that it has been one of the wettest years on record. On some farms it is ironic that we are now in a situation where we see cattle being restricted on grazing during the summer months in order for enough grass to be grown to provide pit silage or bales to feed these same cattle over the winter months.

A lot of second cut silage has been harvested over the last fortnight and farmers are now in a position where they have to decide whether to put these fields back into grazing or to close for a third cut. Grass growth has improved in the last fortnight and for many, this burst of growth is vital to ensure there is enough fodder in the yard for the winter. Whether you decide to go one way or the other, empty all slurry tanks as soon as possible, and well in advance of the closed season. Slurry is a valuable source of nutrients on the farm and can benefit grass and crop growth when applied correctly. One thousand gallons of slurry at 6% dry matter to grass is equivalent to a 50kg bag of 9-5-32 fertiliser when applied by low-emission slurry spreading (LESS). Target slurry at silage fields and fields at index 1 or 2 for P and potassium (K).

Coming into autumn, it is important not to let the eye off the ball and to keep quality grass in the diet of all animals for as long as possible. August is a crucial month to assess the amount of grass available on the farm and to plan final fertiliser strategies for the year. It is important to build grass on the farm from mid-August onwards but we have to be prepared to find equilibrium based on our own situation. We want to build enough grass to extend the grazing season but we do not want to carry very heavy covers into the backend as we may run into issues getting them grazed out. Grass quality remains a challenge on many farms and time is running out before grass build up needs to start. To ensure this happens, fields and paddocks will need corrective action. If conditions allow and fields are suitable, where grass has gotten ahead of you there is an opportunity to take of surplus bales.

However, if no surpluses are appearing on farm, topping after grazing is the next solution.

Grass is a premium product and, on suckler farms, stock that will be going for sale must be given first refusal on grazing rights. Suckler cows have been yielding well all summer but this milk production will begin to decline in the coming weeks, and already, in some instances, the cows are now contributing very little towards the liveweight gain of their calves. Cows for the most part are in great condition after the summer and this can be managed so as to focus the better quality grass to their calves and forcing the cows to clean out fields. This can be achieved through forward creep grazing the calves. A simple system of raising a wire or using a creep gate allows the calves to graze ahead of the cows, offering calve’s first refusal on the leafier grass, which will improve the calves’ liveweight gains in this important period with sales around the corner. Successful weaning is based upon breaking the cow/calf bond over a period of time, thus reducing the impact of stress on the animals and avoiding setbacks in growth. Creep grazing the calves ahead of the cows helps to break this bond.

Now is also a good opportunity to start thinking about lime application for your farm. Consult your soil results and apply lime to paddocks that require it before weather and ground conditions start to deteriorate later on in the autumn. Only apply lime based on a recent soil test report. Don’t exceed 7.5t/ha (3.0t/ac) in a single application. Where more lime is recommended apply 50% now and the balance after 2 years. Target lime to grazing paddocks with low covers (≤ 500 kg DM/ha), recently cut for round bales or reseeded ground.