July 2020 Monthly Management

Building Grass for Autumn Grazing; Over-Sowing With Clover; Grass & Grazing

25 July 2020

Building Grass for Autumn Grazing

The focus of Autumn grassland management is to increase the number of days at grass at the back end of the year while also setting the farm up for next spring.

While winter may seem a long-time away, action will be required in the coming weeks to increase the amount of grass on the farm in the long term.

Generally, the rotation length should be extended from early August. From this period on, the focus is to gradually build pre-grazing covers and rotation length while growth rates are still strong.

Target farm grass cover targets vary depending on stocking rate and soil type. Heavier type soils may not be able to carry heavy pre-grazing covers late September/October.

Date Cover/Cow
(Kg DM)
Average Farm Cover
(Kg DM/Ha)
Rotation Length
1st August 180 450 20 Days
Mid - August 200 500 25 Days
1st September 300 750 30 Days
Mid-September 400-450 1,000-1,100 35 Days
1st October 400 1,000 40 Days
1st November 60% of your grazing platform should be closed for Spring at this stage
Fully Housed 550-600
Mid-August 250 750 25 Days
1st September 330 990 30 Days
Mid-September 370 1100 35 Days
1st October 380 1150 40 Days
1st November 60% of your grazing platform should be closed for Spring at this stage
Fully Housed 600-650
Mid-August 220 770 25 Days
1st September 280 980 30 Days
Mid-September 340 1200 35 Days
1st October 335 1175 40 Days
1st November 70% of your grazing platform should be closed for Spring at this stage
Fully Housed 700-750
This table below shows the autumn grazing targets for three different stocking rates. Source: Teagasc

Be mindful to not allow pre-grazing covers exceed >2,500 Kg Dm/Ha during this time. To maintain grass quality ahead of cows, heavy covers may still need to be removed as surplus bales, but no later than the first week of September. Leaving harvest too late results in paddocks not having enough time to re-grow to make any meaningful contribution in the last rotation.

cows grazing

Points to consider over the next number of weeks to help in increasing the rotation length include:

  • Keep applying Nitrogen to capitalise on August growth rates and to build grass (include some P & K if allowable.
  • Increase supplementary feeding – concentrate and good quality silage bales if growth is below target.
  • Make all land available for grazing to extend the rotation.
  • Remove surplus livestock from the platform to reduce demand.
  • Continue to graze down to 4-4.5cm to stimulate growth and to avoid carrying over dead material into next spring.
  • Use the Pasture Base grass budget to help you build grass and as a guide in relation to supplementation levels.

When peak grass covers are achieved by mid-September, the focus must shift to stretching out the grass supply until housing. Maintaining grass in the cows’ diet will have a positive effect on milk yield and composition. The Autumn grassland planner is a key tool at this stage.

Over-Sowing With Clover

To overcome challenges related to weed control, especially with docks and chickweed, over-sowing is a viable establishment option for clover in grassland. Over-sowing into an existing sward requires a rate of 1.5 kg of pelleted clover to allow it to compete with the existing sward. Pelleted (coated) clover can improve the establishment of white clover in over-sowing situations. The coating contains beneficial ingredients to aid faster germination and provide more energy to the seed.

Key points for over-sowing

  • Soil must be visible – do not over-sow into a thick matt of grass. If the seed does not have enough contact with soil, it will not germinate.
  • Control weeds before you consider over-sowing clover (allow enough time after spraying for herbicide residues to biodegrade).
  • Ideally after a silage harvest or a tight grazing the soil is exposed.
  • Soil moisture is critically important once sown. Avoid prolonged dry periods when

If using a fertiliser spreader:

  • Clover seed can be broadcast with one bag of 0:7:30 per acre
  • To minimise the risk of segregation, only mix the required amount of seed and fertiliser on-site in the field designated for the seed. Sow a maximum of 5 acres at a time
  • Spread in 2 directions – up & down the field and then across the field
  • If desired, apply watery slurry after sowing.

Post sowing management:

  • Graze about 10 days after over sowing and graze every 2 weeks for the next 3 grazings.
  • Do not apply nitrogen (ideally skip nitrogen for the rest of the year, but at least for 2 rounds).

Clover for Derogation Farms

From January 2020, all derogation farms are required to incorporate clover in new reseeds*.

Inclusion Rates:

A minimum of 1.5kg/ha naked clover seed OR 2.5kg/ha of pelleted clover seed is required for all new grass reseeds. Either white (grazing) or red (cutting) or mixture of clovers can be used.

*Please note the Drinagh D74 No-Clover and Superior Silage grass seed mixes do not contain any clover.

Grass & Grazing

This month’s feature farm is Ivor and Alice Deane from Ballyhalwick Dunmanway.

Ivor and Peter Deane
Ivor and Peter Deane pictured on their family-run dairy farm.
Date 17/07/2020
Average farm cover 701 kg DM/ha
Yield (litres/cow) 22 litres
Fat% 4.38%
Protein % 3.53%
Kgs Milk Solids / cow 1.79 kg MS
Supplement fed(kg/cow) 2kg
Pre-grazing covers 1500 kg DM
Days grass ahead 13 days

Grass Growth Update

Grass growth for the last week has been very good with a growth rate of 76kg DM/ha. The average farm cover is 701kg DM/ha at the moment. The farm is currently stocked at 3.29 LU/ha so the cover per livestock unit is 213kg DM/LU or 13 days grass ahead. The cows are currently on 2 kg of supplement and demand is 56 kg DM/ha/day. Growth is comfortably exceeding demand for now. Two paddocks were taken out for silage last week and one paddock was taken out this week for silage to control surpluses. The breeding season lasted 10 weeks this year and finished on the farm on the 5th of July. The herd is currently doing 1.79kgs of milk solids.

Second Cut Silage

40 acres (including some grazing paddocks) were cut for second cut silage recently. The yield was quite good and the quality looks promising due to the early harvest.
The main focus for the next few weeks is to setup the farm with enough quality grass for the latter stages of the grazing season as stocking rate is high. Corrections will be made to fields if necessary, to maintain quality.


The next round of fertiliser will be 27 units of nitrogen either in the form of protected urea or CAN.