Autumn grassland management and looking ahead to 2025

Despite the on/off grass growth patterns we have had this summer, Co-ordinator of the Teagasc/Tirlán Future Farm Programme, Sandra Hayes explains why it is still important to re-focus our minds now to build grass for the autumn.

The main aim of building this autumn grass is to increase the number of days at grass and animal performance, but also to set the farm up during the final rotation to grow grass over winter. Effectively, you need to manage both your supply and demand for grass to build farm cover. The table below shows the options available to manage grass supply and grass demand on farms. A combination of many of these will help you achieve your targets and the means employed will vary from farm to farm and scenario to scenario.

Options to increase grass supply and reduce demand on farms

But how does a farmer know where they are at when trying to build? Grass measuring using the PastureBase Ireland app is what the Teagasc Tirlán Future farmers use. By walking the farm every 7 to 10 days and recording the covers, they can adjust very quickly to the situation. For example during a visit in late July to monitor farmer Steven Fitzgerald farming near Aglish, Co. Waterford, he decided to take the opportunity to get some paddocks tidied up for closing. Due to the poorer growth rates in the summer, some paddocks had poor graze out and this was a chance when growth rates jumped higher than demand to take them out as surplus bales.

Over 30 acres were taken out and 120 bales made. This ground then got watery slurry / chemical fertiliser and was straight back into the grass wedge. If Steven had delayed in taking out this surplus, it would have delayed in his autumn build-up of grass.

Steven’s stocking rate on the milking platform is 2.6LU/ha so his target was to have an average farm cover (AFC) of 750kg DM/ha for the 1^st of September. As of the start of September, he had an AFC of over 790kg DM/ha. Ground used previously for bales and all reseeded ground is all back in for grazing.

One of Steven’s paddocks now available for autumn grazing

Another monitor farmer, John Ryan based in Gortnahoe, Co. Tipperary decided after my mid-August visit that a plan had to be put in place to build as his previous growth rate had been lower than his demand. John is stocked at 4.5LU/ha, but he has a block of land very close by but which is not able to be grazed by the cows. So he zero grazes this block, usually in the spring and autumn and takes silage off it during the year. We calculated using PastureBase Ireland that if 5kg/DM/cow of zero grazed grass came in to reduce demand for two weeks then the farm would build to near 950-1000kg DM/ha where it needed to be. The zero grazed grass reduced the demand and allowed John to slow down the rotation and build grass at home.

In making these decisions, we were able to use reports on PastureBase to see what happened over the last few years in building grass. We also used the predicted grass planner which is a great help. John also mentioned that by attending his local discussion group meetings, it is a great way of seeing how other farmers in his locality are doing and sharing ideas that work. John is continuing to bring in zero grazed grass as the growth fell to less than we predicted so by weekly walking the farm John knew to keep the zero grazed grass in to reduce demand and help the milking platform build grass.

The excellent graze out from John’s cows ensuring a residual of 4cm

Closing targets

Below is a table which is a good guide for helping to see where you need to be for your farm at your own particular stocking rate. Remember it is a guide and every farm is different. The main thing is to remember is that the benefits of building grass and having cows out grazing longer into the autumn reduces the pressures on your silage stocks, reducing the need to feed extra meal and incur extra costs and it sets the farm up for spring grazing.

Aim: To build rotation length to 35 days by mid –September

• Be flexible – an autumn budget is a target for grass supply relative to growth and demand.
• Take action early and Measure and /or walk the farm regularly
• Once you know this, informed decisions can be made.
• Closing farm cover of 550-600kg DM/ha with covers ranging from 900kg DM/ha - first paddock closed to 200kg DM/ha - last paddock closed.
• Graze tight to a residual of 4 – 4.5 cm in the autumn to stimulate growth throughout the winter
• Use a strip wire to allocate correctly and avoid poaching
• Start closing paddocks from the 10^th October onwards (1-2 weeks earlier in wet areas).
• Aim to have 60% farm closed by the end of the first week of November (1-2 weeks earlier in wet areas). The paddocks grazed by this date will have an opportunity to grow grass before growth rates decline in November.
• Do not re-graze fields that have been closed as Spring grass availability will be reduced.
• Feed supplements if there is insufficient grass in the daily allocation.
• Skip heavier paddocks if necessary – and graze paddocks with ideal covers - to meet 60% target if necessary.
• Use wet weather grazing techniques if ground conditions deteriorate (on-off grazing, strip wires).
• Remember hard work on last round pays dividends in the 1^st round next spring!