Grass 10 Update November 8th
Get grassland advice and information from the Grass 10 team. PastureBase Ireland was not available this week due to an upgrade. Topics this week include reducing the cost of nitrogen fertiliser. This weeks Clover Reporter is William Dennehy from Co. Kerry
PastureBase Ireland - Review of Grass Growth in 2022
- 400kg DM/ha in May, this is an increase on 2021
- 420kg DM/ha in June, a decrease on 2021
- 450kg DM/ha in July and August down from the previous year
- 640kg DM/ha in September, down from 2021
- Overall there was a decrease of 1,200kg DM/ha compared to 2021
Predicted Grass Growth
Counties map showing predicted grass growth in kg DM/ha/day over the next 7 days. This is from farms involved in Elodie Ruelle’s MoSt grass growth model on 78 farms.
Growth rates vary across the country vary with Cork, Limerick Kildare, Meath and Westmeath at 18kg DM/ha/day. Lowest raates are 10 and 11kg DM/ha/day in ranging with lows of 10 in Clare, 11 in Clare, Donegal and Wicklow
Predicted rainfall
Counties map showing predicted rainfall in mm for the next 7 days from farms involved in Elodie Ruelle’s MoSt grass growth model - 78 farms.
Rainfall this week is predicted to be heaviest in the western counties of at 58mm to 68mm in Sligo, Mayo, Galway and Clare. Predicted lowest rainfall this week is in the eastern counties of Louth, Meath and Kildare at only 9mm to 10mm
Grass Dry Matter %
- Moorepark 13% - weather wet. Cover 1,800Kg DM/Ha
- Ballyhaise 11%
- Grange 12.5%
- Athenry 13%
Grass 10 Weekly Tips
- December 1st closing cover is the number one priority now
- On-off grazing to keep animals grazing
- Identify grazing infrastructure improvements
- Get ready to take your soil samples
December 1st closing cover is the number one priority now
With most of the farm closed, the priority has to be looking ahead to match your opening average farm cover in the spring to your demand for grass in the spring. Every day at grass next spring will be worth about €4 per cow per day on a dairy farm, or about €2.75 per LU on a beef farm. Herds with a big demand on dry soils can require 1100-1200 Kg DM/ha in early February whilst lower stocked farms requiring 900-1000 Kg DM/ha and heavy soils around 800 Kg DM/ha, which is weather dependent. Using these figures as guides for your farm. You can subtract your winter growth which can range from nearly zero on colder, wetter soils to 5-6 Kg DM/ha per day on drier, warmer soils.
Typically over winter growth stands around 3 Kg DM/ha per day, or around 200 Kg DM/ha of growth over the winter. This allows us to work out what our closing farm cover on December 1st should be, the diagram below also gives guidance.
2.5 LU/ha – 650-700 KgDM/ha
3.0 LU/ha – 700-750 KgDM/ha
3.5 LU/ha – 750-800 KgDM/ha
Continue to walk the farm to reach the closing targets. Neglecting to do this results in being below the target closing cover and in a grass deficit in the spring. This will make spring 2023 a lot more expensive so it pays to walk grass - even in November!
On-off grazing to keep animals grazing
To say the least, grazing conditions are challenging across the country. Many farms have had no option but to house animals with a lot of grass still available to graze. With more heavy rain forecast in the western half of the country. As well as a break from the rain, times like these call for top grazing infrastructure and management to get animals back out grazing.
In most cases, farmers looking to get animals back to grass will have to use on-off grazing. This means letting cows or cattle out during the day for a period of time and rehousing to avoid damage. This requires stripwires in front of and in some cases a back fence behind to minimise hoof damage and poaching.
Access points are key to allow stock movement in and out through different entry points. The priority is to first feed the animals, then avoid poaching, and then graze out tight. Silage management is critical during on-off grazing. It's important animals don't go out grazing when full on silage. So restriction of silage before animals go grazing is important. Be flexible - if housed, getting out again in November may be an option to graze off heavy covers and clover paddocks with 1000 KgDM/ha + before the winter. Remember to persist but avoid poaching!
Identify grazing infrastructure improvements
With the onslaught of heavy rain during October, there has never been a better time to assess grazing infrastructure on your farm due to the challenge of keeping animals out at grass. Could you be grazing this week if you had extra roadways, access points, spur-roads, fencing, water troughs, etc. available on your farm? Identify infrastructure you need to improve in 2023. Write it down on your 2023 to-do list, and save a reminder on your phone for next summer to make the improvements when the weather conditions are good!
Get ready to take your soil samples
John O'Loughlin from Grassland Agro shares some of his top tips when it comes to soil sampling and acting on the results. Getting the fertiliser plan in place to improve soil fertility will reward farms in the long run.
John O'Loughlin, Grassland Agro (pictured above) says the key to soil sampling is to act in time to get accurate results, and then to use the information. Soil sampling early will mitigate potential delays during the peak season. This information can then be used to devise a lime or Potash strategy for the back end when/if ground conditions allow.
Soil samples can be taken 3 months from the last application of chemical or organic (Slurry) P and K or lime. Straight N or N and S fertilisers will not impact sample results.
Fertiliser prices are forecasted to be very strong for next year. Only 25% efficiency of chemical N will be achieved with suboptimal pH, P and K, so it is more important than ever to soil sample. John adds, "in practical terms, this means, that the cost of N is 4 times the price paid to your coop or merchant when you apply it to parts of the farm that are not optimum soil fertility".
*Farms stocked between 130-170 kg organic N/ha without soil samples in the last 4 years will be assumed to be Soil P Index 4 and resultantly will have zero P allowance
Figure 1: Ideal Closing Farm Cover 1st December 650-700 Kg DM/Ha 
This graph shows the relationship between the 60:40 autumn rotation planner and the average farm cover (AFC) target in order to close up the farm in the autumn with the appropriate quantity of grass for the spring. The objective here is to have an AFC of 650-700 KgDM/ha on December 1st this would be sufficient for a farm stocked at 2.5 LU/ha in the spring. If the demand for grass is higher, then the target AFC on December 1st should increase to 750-800 KgDM/ha depending on farm circumstance. Remember spring grass is a lot more profitable than autumn grass, avoid the temptation and get 2023 off to a flying start!
The Clover Reporter
William Dennehy, Co Kerry
William is a dairy farmer outside Castleisland in Co. Kerry. The wet weather has put a stop to grazing, however, there are at least 10 grazings left. William would like to graze some of the closed clover paddocks which have 1000 KgDM/ha or more back on them with recent growthV
Location: Currow, Castleisland, Co. Kerry
Soil Type: Medium Soils in a high rainfall area
2021 % Farm in Clover: 36% (11.89 Ha)
% from Reseeding: 33% (3.9Ha)
% from Oversowing: 67% (7.99Ha)
Clover content 2021: 17%
Total % Farm in Clover: 45%
Read William's full report here
