Grass+: hitting peak average grass cover on farms

Variable growth persisted across the country again this week as parts of the east have still had very little rain.

The average growth rate for the week was 62kg DM/ha.

Growth rates are expected to pick up towards the end of the week as rain is forecast for most areas.

As we move into the middle of September and hit peak average farm cover (AFC), it is time to reassess the autumn grass budget again and make adjustments where necessary.

Target peak AFC should be between 1,000kg DM/ha and 1,200kg DM/ha depending on stocking rate. At this stage the rotation length should be pushed out to 35 days. This can be achieved by dividing the total grazing area by the number of days in the rotation. For example, on a 100 acre (40 ha) farm over a 35-day rotation the cows will graze 2.9 acres (1.14 ha) per day. Deficits can be made up with meal and silage.

Farms that are behind target should increase meal and feed silage now and take advantage of the good growth rates. Feeding during high growth helps to build grass in a shorter period.

The time for spreading N and P fertiliser is now over. However, slurry can still be spread up until 15 October which will help maintain grass and promote growth over the coming months.

Potassium can be spread at any time of the year but while conditions are suitable now is a good time to do it. Likewise, conditions are very good for lime application which will help correct the pH of the soil, ensuring P and K in the soil is available to the grass. Lime and K applications are often put off to later in the year and if the weather changes the opportunity to spread can often be missed.

Swardwatch

- 31,050kg DM/ha on farms stocked at 2.5LU/ha.

- 31,150kg DM/ha on farms stocked at 3LU/ha.

- 31,200kg DM/ha on farms 3stocked at 3.5LU/ha.

Caroline O’Sullivan – Curtins Teagasc

The average farm cover on the grass-only swards is 751kg DM/ha which is behind target but with a low stocking rate the C/LU is 359kg DM/LU so we are not overly concerned. The AFC on the multispecies swards is 926kg DM/ha and on the grass plus clover swards it is 913kg DM/ha. Last week the whole farm was bulk-spread with the last application of N for the year. The multispecies and clover swards got 20 units of N per acre. This was the first N these swards got since May. The grass only got 30 units of N per acre. In the coming weeks we will be putting out K at a rate of 50 units per acre on paddocks with a K index of 3 or below.

Barry Reilly – Teagasc Ballyhaise

Pre-grazing covers are at 2,400kg DM/ha. Grazing conditions have been excellent so the residual is still 4cm in most cases. This week we increased the rotation length to 36 days. We are following the grass budget on PastureBase. Last week all the paddocks in index two for K got 50 units of K. The index 3 paddocks got a reduced maintenance level plus some paddocks got slurry throughout the year. Clover paddocks are looking good with 30% of the farm incorporated into clover and grass via full reseed and over-sowing during the 2021 grazing season. Cow production is good at 1.55kg MS per day; SCC is 170.

Dunphy Family – Easkey, Co Sligo

Last week we went with the final application of N and blanket spread the whole farm with 20 units per acre. Since the end of July we have spread 200t of ground lime. The plan is to go with 25 units of K on the low-index paddocks after each grazing this round. Pre-grazing covers are 2,000kg DM/ha. We are on a 30-day rotation but will extend this to 35 days this weekend. For the first time this year growth rates have been very good for a prolonged period which has made building covers easier. We have a target peak average farm cover of 1,100kg DM/ha which we should hit in the middle of next week or so.

Shaun Diver – Tullamore Farm, Co Offaly

In recent weeks the farm has been growing more grass than normal for the time of year. We are well ahead of our target grass growth and hope to begin closing off paddocks towards the end of the month. Having spread some fertiliser last week, grass should be able to stay on target for the coming months. We recently drafted and sold 17 lambs with an average price of €132. There are 50 lambs left on farm for sale. We hope to have all lambs gone within the next six weeks. We spread our last nitrogen last week to give us another flush of grass ahead of ewes breeding. On the farm we are currently prepping in-calf heifers for a sale on 27 October in Roscrea Mart. We’ll have around 25 in-calf heifers for this year’s sale.

Trevor Boland – Sligo

I spread one bag/acre of 18-6-12 two weeks ago on most of the grazing block. Currently the farm is ahead on grass growth for the time of year, with closing off time coming soon for paddocks. At the moment, things are pretty well on target in terms of grass growth and the closing-up plan. All the autumn-calving cows have calved on farm with no big issues to report and all are coming good and healthy. It has been a textbook autumn for autumn calving in fairness and the weather has made all the difference. I find autumn-calved cows are harder on grass at this time of year compared to the spring due to the quality of grass being poorer and lower dry matters. But we have lots of grass ahead of us so hopefully we won’t have to house for a few weeks.

Chris McCarthy – Westmeath

August and September are always quiet months around here. Over the last few weeks we have been weighing for BEEP and dosing calves.

There were 25 units of CAN/acre spread on the farm two weeks ago to increase the farm growth prior to closing off paddocks around 10 October.

Grass growth on the farm has been very good over the last few weeks and we will be able to keep weanlings out for another few months if weather permits. I have 30 days ahead on this rotation with grass. In the coming weeks the calves will be weaned. They are currently being creep-grazed ahead of the cows where they have access to concentrates.This reduces stress at weaning and keeps us compliant with BEEP requirements.