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Farm Update July 2023

Carbon Flux Tower and Shallow Drained Peat

A little over a year ago we started into a conversation with the Teagasc research team from Johnstown Castle in Wexford about the possibility of installing an eddy covariance tower in the college. Like most midland farms we have a variety of soil types but it was the shallow peat land that the team were particularly interested in. So after a number of site tours and a little bit of soil analysis they picked a spot. It was a field with about 6 to 12 inches of drained peat or as we’d call it reclaimed bog.

The eddy covariance tower was installed and the team gave us a great rundown of how it all works but to put it as simply as I can the tower measures the carbon and methane going in and out of the soil, also known as ‘net ecosystem exchange’. Eddy covariance towers measure 10 times a second averaged over 30 minutes year-round, providing a very accurate time series which was not previously possible. The tower also measures many other things like air & soil temperature, soil moisture at different depths, wind speed, rainfall and sunlight, but all this is to help analyse and understand the flow of carbon and methane in and out of the soil.

After a few more months the team started discussing with us the possibility of “re-wetting” the field with the tower, this was met with much reluctance and caution from those of us in the college. We had images in our heads of the field completely flooded and all the drains 100% blocked. The team from Johnstown were quick to put us at ease explaining that the image in our heads was not at all what they were trying to achieve, their goal was to manage the water table by slowing the flow in our drain by installing a shallow dam that would still allow water to pass over it, just slowing the flow. So in January of this year the shallow dam was installed in our drain to slow the flow of water.

We kept a close eye on this dam as we didn’t really know what effect it would have on the water table in this field. It is very difficult to say how it affected the field with only one spring of the drain being dammed but it felt like the field became travelable about a week later than it would of before the dam was installed. It’ll be interesting to see how it effects the field in the autumn and into the future.

From our side we have to supply the research team with information on grazing dates, stock numbers, fertiliser spreading etc. They can monitor the readings from the tower remotely but they come onsite every week to do maintenance and check that all the equipment is functioning properly as well as taking other measurements such as water table level and grass height. They tell us that they are getting some very interesting information from the eddy covariance  tower and when they have enough data collected and analysed they are looking forward to painting an accurate picture of the carbon budget. Some early data suggests that the site is emitting less carbon dioxide than previously thought. The IPCC currently define a drained nutrient rich organic soil to emit over 20t CO2 eq ha-1 per year, whereas the early data suggests that this Irish study is lower. This is pending final analysis such as inclusion of methane and export of carbon in grazing events. It is also very interesting to have an eddy covariance tower on a site pre and post “re-wetting” it will be interesting to see the carbon dioxide and methane data. They tell us it’s early days yet but we are hopeful of a good news story for Irish agriculture.

The data from this tower provides the agricultural sector with an opportunity to lower emissions. As shown in a paper by Pat Tuohy et al. (2023) there are a number of uncertainties with these sites, namely drainage status and the data of carbon dioxide exchange. The tower in Gurteen can help verify if this theory is correct with on the ground data.


Farm Update June 2023

Clover Management

Traditionally we reseeded fields with just one kg of white clover in the grass seed mix, but since 2022 we have started including two kg of white clover seed into the mix and when you think of the number of seeds in one kg of clover seed, that’s a lot of extra seeds. After establishment, we cut the nitrogen applications by 50% in the fields with the clover to try stop the grass over powering the clover as it establishes itself.  Once established the reduced nitrogen is continued as the clover should be putting its own nitrogen into the soil. In some of our fields we have had great establishment of clover.  In others where the clover is visibly thinner, I struggle to give any particular reason for this.  The soil analysis are good in all the fields, and they were treated the same, but in some cases it just didn’t establish as well as others. Some people have run into trouble with bloat in the clover rich swards and have had to take steps such as giving the cows a small strip and making them graze it bare before giving them the rest of the paddock. This stops the cows moving through the paddock picking out the clover first and forces them to eat the grass too in that first strip which helps dilute the clover in her stomach and reduce the risk of clover. So far we have been lucky and not experienced any serious cases of bloat due to clover but we are always mindful of it in the clover rich swards.

Red Clover Silage

In September 2022 we tried sowing red clover for the first time. We sowed the field with a grass seed mixture including 2kg of red clover. By the time we sowed it the fertiliser spreading season was closed so it had to wait for the spring, when we gave it 2 bags of 10-10-20. This got the growth going.  Then on the 27th of March we spread another 2.5 bags of 18-6-12 and closed it for silage. That was 65 units of N in total, compared to the normal 100 units we would spread for first cut silage. It also got 2,500 gallon of slurry, the same as the rest of the silage ground.

Walking the field before mowing silage there was a lot of clover visible.  It certainly felt like there was a good establishment with the red clover growing tall enough that it wasn’t smothered out by the grass, it was clearly visible. We tested the grass in all the silage fields for sugars and nitrogen two days before we mowed.  The field with the red clover was fine for sugars but the nitrogen level was very slightly high, so we gave this field a little extra wilting time.  We also use an additive on the silage and we increased the dose rate slightly for this field to counteract the nitrogen. I am expecting to get some good quality, high protein silage from this field.


Farm Update May 2023

Milking Unit

In Gurteen we have always felt a responsibility to be environmentally sustainable. For us an important piece in the sustainability jigsaw is energy reduction. In September 2018 we started milking in our new milking parlour. The milking plant was designed to have a heat exchanger installed. When the compressor is running to cool the bulk tank, the excess heat off the compressor is captured and fed through a heat exchanger, which is used to heat two buffer tanks. The heat exchangers will bring the temperature in the buffer tanks from 7 degrees up to almost 30 degrees. The gas boilers used to supply hot water for washing the milking machine are fed from the buffer tanks, so the heat exchanger has already raised the temperature in the buffer tanks up to 30 degrees and then the gas boilers boost the temperature up to 85 degrees for washing. When heating water most of the energy is used to bring the water from the ambient temperature up to that 25-30 degree mark, making the load on the gas boilers much less. It is estimated that we save €1,300 per year on water heating in the milking parlour by using the heat exchangers. We also installed variable speed drives for the vacuum on the milking machine, these are becoming common place in newer milking parlours. They greatly reduce the electricity requirement to run the milking machine and have the added bonus of being very quiet. You can stand in the plant room when milking is happening and talk at normal voice level. 

Biomass Boilers

The entire college is heated by the two biomass boilers. We burn a combination of home grown willow and logs (forestry thinnings). This system works very well for us, as we have the capacity to grow, dry and burn the willow onsite. It may not be as efficient for other businesses who don’t have that same capacity. We grow 80 acres of willow and we cut one third of it every year, this means we are always cutting 3 year old growth. After we cut the willow it naturally regrows again. It is cut with a self propelled silage harvester with a specially built head. Once harvested we store the willow on a drying floor, on the drying floor we can blow hot or cold air up through the crop to dry it from 45% moisture down to 20% moisture (the required moisture content for the boilers). We also buy 400 tonnes of logs to supplement the willow. We allow the logs to dry naturally by stacking them in an exposed location and we lose 50% of that weight in drying losses, so we end up with 200 tonnes of dried logs, these are then chipped and ready for burning. For 2022, it cost us a total of €45,000 to heat the College using willow and logs.  To put this into context, we estimated to heat the college with heating oil would have cost us €250,000 for the same period, with the added bonus of willow and logs being carbon neutral. 



Farm Update April 2023

Reseeding and clover incorporation

Reseeding & Clover


I think reseeding and clover incorporation is a subject where the learning process never ends. In the past we would of selected our grass seed mix with 1kg of clover in it and honestly there was little thought given to the clover after that, even though we were well aware of how clover fixes nitrogen.

Probably through a combination of the campaigns to raise awareness of clover and the dramatic price increases in fertiliser much more thought has been given to clover in recent years.

In our grazing paddocks that we reseeded in September we decided to make the move from 1kg of clover to 2 kg of clover. When you think of the size of a clover seed, putting an extra kg of clover seed into every bag is a lot of seeds. There are certainly signs of clover in the new swards but as farmers are well aware the challenge then becomes to keep the clover in the sward.  


Red Clover Silage


We also reseeded one of our silage fields last September, which had been in cereals for the previous two years. What we tried here was adding 2kg of red clover seed into the grass seed mix. Red clover is much better able to withstand the silage making process than white clover, so our hope is that we will manage to sustain the red clover in the silage ground. As this is our first field with red clover we still have lots to learn but our plan is to take an early cut of silage off it and hopefully get a total of 3 cuts of it, we will then graze it in the back end only because if grazed too much the red clover will quickly die out. We will keep this silage separate to our other silage as it should make higher protein silage with good dmd’s. As we learn about managing red clover and making red clover silage we hope to reseed more silage ground with the inclusion of red clover. 


Reseeding Methods


We have used lots of different methods to reseed over the years and we have learned they all work. Our two main methods now are plough, power harrow, sow and direct drilling. Land that needs to be levelled or land that is coming out of the tillage rotation and back into grass will always be ploughed. Ground that doesn’t need to be levelled is sprayed off and direct drilled. I’ve often heard people debating around how one is much better than the other but I have found the thing that has the biggest effect is the weather around the time of sowing.  


Get your Indices Right


We hope our new emphasis on clover content will lead us to reduced nitrogen use and reduced costs as well as improved sward quality and better soil structure and fertility. It’s a very short article to be giving advice from but for anyone who is starting their journey on promoting clover in their swards I’d say make sure your P and K indexes are right before you start, cut back on your nitrogen fertiliser in those fields to allow the clover to establish and time would wisely be spent in learning about how to manage the sward to keep the clover in it and how to avoid bloat in livestock grazing clover rich swards.  


Gurteen College Farm Current Update


We have considered slurry to be a valuable source of nutrients for a long time now and would have always said that we spent time planning our slurry application to make the most effective use of it. However, when the price of fertiliser skyrocketed last year, we spend double the time planning our slurry application for the year and it was at that moment I realised that even though we thought we were doing great work planning our slurry application there was much room for improvement.

Through long term planning and yard development we are in the lucky position that we are very rarely under pressure for slurry storage, which gives the added benefit of applying slurry when we want rather than being forced to spread because tanks are full. We aim to go out in February.  On our bare paddocks we apply 2,000 gallons per acre, then as the cows graze the heavier covers we try to follow them with the same application.  So ground conditions allowing, all paddock get 2,000 gallons of slutty either before or after the first grazing. There are always some areas that are too wet to spread.

We then turn our attention the silage ground which will get 2,500 gallons per acre, at this time of year we also look at our paddocks with lower P and K indexes and try to give them an additional application of slurry. One of the interesting things our soil samples have shown us, is that our only paddocks with low P and K indexes are the wetter paddocks. We very quickly realised that this was caused by years of avoiding the wet paddocks with the slurry tanker and always applying slurry to the dry paddocks, so now when ground conditions allow we prioritise those paddocks with low indexes. Then, after first cut silage, slurry stocks are usually getting low and we will prioritise the silage ground with the poorer soil analysis.

This year we have started to get our slurry tested and get back a nutrient value for it.

The slurry sample has to be taken when the tank is mixed and the easiest place to get a sample is from the back of the tanker, that means the slurry is spread before we have the results for it. But that’s ok, we are in this for the long haul, we will then use the test results to build a picture of what P and K value we can put on each of the different tanks.  Some slurry is more watered down than others.  Some is from sheds that house beef cattle on high concentrate diets, others from dry cows, others are from sucklers or weanlings, and they all produce different results. After a couple of years, we will have a good average of the value of the slurry in the different tanks and we can adjust our spread rate according to what tank we are spreading from and what field we are going to. There is an old saying, if you don’t measure it you can’t manage it.  Knowing what nutrient value is in our different slurry tanks allows us to better manage our slurry.

We have been spreading with a trailing shoe for 3 years now and we are definitely seeing a difference, better nutrient uptake by the plant, less taint to the grass when cows are grazing and reduced odour. We have a turbo evo pump on our tanker, which has a macerator in it.  The slurry passes through this macerator while filling and emptying so the slurry is chopped twice before it reaches the distribution head on the trailing shoe.  Between this and being careful about good mixing of the slurry and trying not to allow too many forging objects into the slurry tanks we find blockages in the trailing shoe aren’t an issue.


Gurteen College Farm

Gurteen College at Ballingarry, Co. Tipperary has students coming from all counties. Gurteen offers students a level 6 qualification in agriculture with a chance to specialise in dairy, drystock or crops and machinery, the college has a proud history of providing hands on learning. This year Gurteen is also offering a degree in Ag Science and Sustainability in conjunction with Technical University Shannon. The College has a 1000 acre farm with dairy, beef, sheep, tillage, forestry and willow.

The Herd

Gurteen dairy herd has 240 pedigree Holstein Friesian cows spring calving milking 6164litres annually.  We are producing 510kg milk solids with 3.55% milk protein and 4.2% milk fat.  The stocking rate of the dairy unit is 2.8 LU / ha and the milk output is produced on 1.3 tonne of meal and growing 13.5t DM of grass on 85 ha grazing platform. In Spring 2023 we have 80 heifers to calf and 179 cows with 85% expected to calf in 6 weeks.  Excess heifers will be sold. We rear 50 bull calves, the remaining bulls are sold through the mart and all dairy and beef replacement heifer calves been reared for 12 weeks before been transferred to the Drystock unit.


The EBI of the dairy herd is €183 with the top 10% being €194.  The 2021 heifers have an EBI of €214 and the 2022 heifers have an EBI of €223.  We have good breeding performance with a calving interval of 370 days and a six week calving rate of 84%.  Our replacement rate is 22%.  Friesian heifer replacements are contract reared by the drystock unit. The Dairy has 2.5 full time labour units and relieve help after that.

Plans for improving sustainability

This is a busy teaching farm and its important to us that there is an emphasis on sustainability on the farm across the main areas including reducing emissions, improving water quality and enhancing biodiversity on the farm.  The next generation of farmers need to see sustainability in action on our farm.  To reduce emissions, we have been using protected urea for some time with good success.  A focus for 2023 is on reducing our reliance on chemical nitrogen which will be good for our pocket and good for the environment.  We will achieve this reduction through a combination of good soil fertility, making best use of slurry and incorporation of clover into our grassland swards.  We want to increase the potential of our soils to sequester carbon.  We have a flux tower on the farm which is recording carbon exchange in real time which will give us some valuable information.  As regards water quality, we are very conscious of buffer zones, fencing our waterways and we are considering some tree planting in 2023.  Part of our plan to improve biodiversity on the farm is to incorporate more hedgerows and plant trees.  Reducing our energy demands is important to the farm.  We have solar PV panels installed, use willow biomass to fuel the heating system for the entire college and rain water harvesting for use in washing down the parlour.  We have a miniature anaerobic digestor unit which we hope to get up and running later this year.     With a lot happening on the farm, I hope to share what we are doing in all these areas over the coming months. 

2023 targets:

In 2023 the Gurteen Cow aims to achieve: 

  • 510kg milk solids per year
  • >8.1% combined fat and protein
  • Peak 2.2kg milk solids at grass
  • 85% of bodyweight as milk solids
  • 82% of diet as forage
  • 85% calved in 6 weeks in Spring
  • Low incidence of lameness
  • Correct udders with low SCC
  • Herd EBI in the top 10% of Irish dairy herds.
  • 70 Friesian Heifer to breed
  • Plan to milk 240 cows on 85ha
  • Target to improve clover is to stay below 150kg/ha, we are now one of the signpost host farms 
  • Target to wean calves @ 100kg
  • Target to breed heifers at 330kg @ 15 months 60% 

           550kg @ 24 months .

  • Aim to produce 500kg of milk solids in 300-day lactation and building up to 550kg of milk solids when herd matures. All been done through breeding programme and grassland management. 

2022 production

Replacement Rate %


Protein %


Fat %


Calf mortality


Average EbI


6 week calving interval


Herd ave lact


Stocking rate


Farm Manager: Ken Flynn