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Time for Lime – Low Cost Fertiliser 

Now is the ideal time to apply lime to correct soil pH on mineral soils. Lime will bring many benefits from increasing the availability of soil nutrients (N, P, K & S) to improving soil structure (aeration & drainage). Soils maintained at a soil pH 6.3 to 6.5 will release up to 70kg N/ha/year from soil organic N reserves. This will help reduce chemical fertiliser nitrogen (N) bills on farms by approximately €70/ha/year.  Lime will increase the availability of soil phosphorus (P) and is the first step to improving / building soil P levels cost effectively. Maintaining the optimum soil pH will in addition increase the response to applied N, P & K in either organic manures such as cattle slurry / FYM and N, or bag fertilisers such as 10-10-20 / 18-6-12 etc.

Over the coming days / weeks check soil test results and apply lime to fields based on lime recommendations. Target fields with the lowest soil pH first and apply lime where the opportunity presents for example after grazing paddocks, 2nd / 3rd cut grass silage or at reseeding time. Soils maintained at the optimum soil pH 6.3 will grow approximately 10 to 15% extra grass during the growing season. Ground limestone is the cheapest and most cost effective tool to control soil acidity in the long term. Apply a maximum of 7.5t/ha (3t/ac) ground limestone in a single application.      

Apply potassium to low K Index soils

Approximately 60pc of our soils nationally are at index 1 and 2 for potassium. This means that six out of 10 silage fields are deficient in potassium, and this poses a challenge. Autumn time is the ideal time of year to rectify potassium deficiencies. So why is potassium such an important fertiliser? Potassium is the nutrient taken up in the greatest quantity by grassland swards and has a wide-ranging role in the plant, affecting nutrient uptake, photosynthesis, rate of growth and feed value.

It is particularly important for increasing stem strength, improving drought resistance and cold tolerance, and importantly for increasing yield.

Potassium fertilisation is vital, especially in autumn and on older grass. If adequate amounts of potassium are not available, the rate of growth and yield will be restricted.

There is also a relationship between nitrogen and potassium, as the response of grass to nitrogen is dependent on an available supply of potassium to allow N uptake as nitrate and conversion into proteins.

In silage fields in particular, stem strength is of huge importance. Silage crops low in potassium are more prone to lodging, as the stem cannot hold up the seed head and grass plant.

Padraig O'Kiely's work in Teagasc, Grange on the factors that impact most on silage quality show that lodging is the factor that can lead to the greatest deterioration in the quality of a silage crop and estimates that up to nine units of DMD percentage could be lost by your crop lodging. This means your 70pc DMD silage pit might now be only 61pc DMD.

In looking at the K requirements for 1st cut silage, index 1 and 2 soils for potassium require 120-140 units of potassium/acre.

However, as the recommended amount of K to be applied in a single application is 90 units (three bags 0-7-30/acre), the advice is generally to spread the 90 units and wait until the autumn to spread the balance. In practice, this balance is rarely spread.

The reason why it is advised to only spread 90 units in a single application is because luxury uptake of potassium occurs in rapidly growing spring grass, which has the ability to take up a lot more potassium than it needs for normal plant functioning.

High levels of potassium in the plant interfere with the uptake of magnesium, and low magnesium in the animal's diet is one of the factors causing grass tetany.

Many of us depend on cattle slurry to rectify our potassium deficiencies; as 1,000 gallons of thick cattle slurry will contain approximately 30 units of K, it will go some distance to replacing some of the K off-take from cutting or grazing.

However, in a silage situation, 3,000 gallons/acre provides only 90 units of K at best, meaning we are still short 30-50 units of K on index 1 and 2 soils. The Autumn is the best time to apply this amount.

It is vital to replenish this K to ensure next year's silage crops will grow to their potential and help fill the empty silage pits around the country. A bag of Muriate of Potash (50 units K) should be adequate in most situations.

As there is no legal deadline or maximum rates in relation to potassium, every farmer should look at getting a pallet or two of potassium spread over the next month.


September is the last month you have to build grass covers and extend your grazing rotation length in order to set your farm up for the last grazing rotation in October and November. If you don’t have a reasonable bank of grass saved up by the end of the month, your last rotation could end up being very short and you will have to house all of your stock much sooner than you would like to. September 15 is the last day you can spread nitrogen (N) and phosphorus (P) fertilisers. The sooner any planned fertiliser applications are spread the better, as growth rates tend to decline as the month progresses. No more topping or surplus silage cutting should take place. Dairy cows can be supplemented with meals to allow grass to build. Suckler cows being weaned can be restricted to allow covers to build, especially if they are already in good body condition. Stock being finished off grass should be supplemented with meal, which will reduce their demand for grass. Young calves in dairy calf-to-beef systems should be fed meal at grass from now until housing.  Replacement heifers below target weight should also be supplemented. The target going into October and the last grazing rotation should be to have at least 35 days of grass ahead of stock. If weather conditions allow it, this would mean that some stock will be grazing until November.

In summary, if below target-:

  • Reduce demand with meal and silage. Feed high quality baled silage for 7-10 days. Use a strip wire to allocate grass
  • Remove cull and empty cows from the herd
  • Rotation should be at 35 days from mid September. 120 acre grazing platform should be grazing 3.5 acres per day and the deficit filled with meal and silage

Autumn Grazing Targets




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  

Weigh replacement heifers now

Every year when it comes to selecting replacement heifers with a target to calve at 24 months it becomes apparent that significant number won’t make ‘the cut’.  It is obvious in many cases that these heifers are not achieving the weight for age targets at bulling. Hence, they are left to grow on and calve at 36 months.  Research undertaken by Teagasc shows that delaying calving from 24 months up to 31-32-months for beef cows, costs approximately €490 or €50/heifer/month mostly in the form of feed costs.  On dairy farms the cost of heifers not calving down at 24 months is approximately €70 / head. 

Weighing animals in September will help to identify issues with poor weight gains and allow you to take action before housing.  This may mean feeding supplementary concentrate to supplement Autumn grass and / or implementing a dosing programme to sort out worm / fluke problems. 

Target Weights for Dairy Replacement Heifers

    Maintenance sub index
  % of mature weight €10 €20
6-month weight 30%  177 kg  162 kg 
Pre-breeding weigth  60% 354 kg 324 kg
Pre-calving weight 90% 531 kg 486 kg
  "Mature weight" 590 kg 540 kg

Beef Heifer Weight for Age Targets

Mature Cow Weight  







  Target % of mature cow weight   60% 80%
600 kg   260-280 kg 360 kg 480 kg
700 kg   300-320 kg 420 kg  

Concentrate Feeding

Research at Teagasc Grange has shown that single-suckled beef calves supplemented with concentrates prior to weaning were less immune-compromised, started consuming meal faster when housed indoors, and spent more time lying down (rather than standing and walking) post-weaning compared with non-supplemented calves.

At pasture: Introduce concentrates one month prior to weaning sucklers and gradually increase the allowance with the intention of having the calf consuming one kg/day at weaning time. Continue to feed the concentrates for at least two weeks after weaning.

If feeding supplementary concentrate to replacement heifers, energy is the most deficient nutrient in the Autumn.  Feed a high energy low protein concentrate feed. 

Dosing and Vaccination Programme

Calves should be treated for stomach worms and hoose during the grazing season and for Ostertagia Type II worms at housing using effective anthelmintics administered according to product recommendations. Calves with pre-damaged lungs from lungworm infestation also have a higher risk of developing pneumonia.

With spring calving suckler herds, weaning calves in September-October, now is the time to plan your vaccination programme. Catherine Egan, Teagasc Beef Specialist, highlights that the number one cause of mortality in weanlings in 2020 was pneumonia and she has advice to prevent it on your farm here.  Click here for details 

Milk Recording

Changes in the regulations around antibiotic use means that from 28 January 2022, dairy farmers will no longer be permitted to use dry cow tubes on all cows in a herd at the end of lactation, unless they have evidence that they require them. There are only one more dry-off seasons before the new regulations come into place. 

Milk recording will provide farmers with the evidence needed to show that antibiotics are required. Another advantage of milk recording is that it will show the actual number of cows to be treated and the success of the previous year’s dry cow treatment. If you have never recorded before, now is the time to start.

For a herd that hasn’t milk recorded before, is it too late to start now for this year?

For any herd, the best time to start milk recording is close to the start of lactation. For a herd that hasn’t ever milk recorded, the second-best time to start is now. The reason for this is that all milk recordings will build a build a profile of the mastitis spread and control

Who should I contact about recording?

To start milk recording, ring one of the following numbers:

Progressive Genetics 045-9540606

Munster Al                022-43228

Tipperary Co-op        062-33111

Where can I learn more?

Episode 120 of Teagasc’s Dairy Edge podcast featured an interview with Don Crowley, who discussed the mid-lactation mastitis challenge. Listen below.