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Meeting the challenges of lower chemical N use on my farm - Michael Gowen

Meeting the challenges of lower chemical N use on my farm - Michael Gowen

Dairy farmer Michael Gowen joined the Teagasc Dairy Conference to share his experiences on meeting the challenges of lower chemical N use on his farm. Michael says managing clover will be a challenge but it is a challenge that is achievable.

I farm with my family near Kilworth in Co. Cork. We farm a total of 70.5ha which is 4 blocks. The milking platform is 33ha. I milk 125 cows approximately each year and carry some in calf heifers and calves on the farm with some of the in calf heifers going into a contract rearing arrangement just this year for the first time. The stocking rate on the whole farm is 2.5 LU/ha while the stocking rate on the milking platform is 3.76 cows/ha. In 2021, the herd averaged 488 kgs of Milk solids sold from just over 560 kg of meal fed and will do 520kgs of milk solids this year.

Changing direction

In the past, I would have used every kg of chemical nitrogen allowed to me. However, in the last few years with the increased focus on water quality and emissions, a change in tack was warranted. Having seen all the good work being done in the research centres on clover, I decided that I needed to start down this road in advance of any regulation changes forcing me to do so. This would allow me to adapt to the new changes more quickly and also give me time to make any necessary adjustments to the way I manage the farm.

Soil fertility

Managing soil fertility on the farm is critical to growing high levels of grass and clover. The pH is > 6.5 in all but one of the paddocks. I am fortunate in that from having had pigs on the farm in the past, our P and K indexes are very good with only two paddocks in index 3 for K. All other paddocks are Index 4 for both P and K and this is a big benefit to me in establishing clover on the farm.

Establishing clover

I have established clover in two ways. I have sown clover when reseeding, of which I do approximately 10% every year. However to get the farm in clover as quickly as possible, I am also over-sowing clover. This year I have oversown 15% of the milking platform. It is tricky to manage the over-sown ground given it has to be grazed regularly at lower covers and I have made the mistake of taking on too much area for over-sowing in one year in the past. This creates the problem of several paddocks all needing grazing at the same time to allow the clover to flourish which is difficult to do in practice. With area out for reseeding and stocking rate high during the summer means that grazing high levels of over-sown area could result in the cows running out of grass due to grazing too many low covers. Consequently, some of my over-sowing hasn’t worked out as I couldn’t get to all the ground at the right stage and feed the cows as well. This is a lesson learned. I have over- sowed some of this ground for a 2nd time already and have had greater success establishing it through better management of smaller areas. A combination of 10% reseeding and 15% over-sown done well over the next couple of years should see the whole milking platform in clover by 2025.

Managing clover

The biggest challenge I found was that while I knew it was the right thing to do in terms of reducing nitrogen, going and doing it was another story. I knew that I would be able to establish clover in the sward but managing it was another question. However, there are commercial farms that have done it and are making a success of it and this combined with the success in the research centres down through the years gave me the confidence to at least try it. It is seeing this on-farm experience that give me the confidence that I will overcome any potential knowledge gaps to make a success of it on my farm. Table 1 below shows the performance of the paddocks on my farm under varying management strategies. It highlights to me the performance that can be achieved through clover incorporation and I have reduced the chemical nitrogen use on the farm significantly. This is a big financial saving to the farm allowing me to reduce my input costs. Importantly, this saving has come with no reduction in herd performance. I am also contributing to reduced N loss to water and I am reducing nitrous oxide emissions.

Table 1. Data to 15/11/2022 showing the effect of various nitrogen strategies on grass growth on the Gowen farm in 2022
 Area(ha)No. ofGrazingsGrazing(kg DM/ ha)Silage(kg DM/ ha)Total(kg DM/ ha)Total N kg/haChem N kg/ haChem P kg/haChem K kg/ha
Grass only 9.3 7.2 10,249 1,080 11,329 198 186 3 34
Clover-Spring N 2.0 8.0 12,413   12,413 79 39 0 20
Clover-Zerochemical N 8.9 9.4 12,234   12,234 36 3 0 39
Clover- Spring N &half ratesummer  9.2  9.0  11,291  370  11,661  161  121  1  33
2022 Springreseeds 3.6 8.0 10,496   10,496 108 87 19 68


Managing clover will be a challenge but it is a challenge that is achievable. There is an ever increasing amount of information coming from research centres and learnings from commercial farms putting the advice into practice that farmers can learn from to make clover on their farms a success.

Read the National Dairy Conference 2022 publication here