How this meat farmer reduced chemical nitrogen use by 49 kg/ha without affecting production

I am very pleased with the progress made this year to reduce our reliance on chemical fertilizers. I was always concerned that if I reduced chemical N I would lose production and profitability.

However, working closely with my advisors Owen McPartland and Niamh Lynch, and trusting the research, I managed to reduce chemical nitrogen use by 49kg/ha in 2022 compared to 2021, but I maintained production.

It is forecast that we will reach 500kg milk solids per cow by the end of the year compared to 487kg MS in 2021. Owen tells me they can do more.

Grass production in 2022 was 12.5 tDM/ha, down 0.9 tDM/ha, but I think a lot of that is due to the drought in the main grazing season.

Regardless of what fertilizer you apply, if you don’t have moisture, you won’t grow grass. The mitigation of these drought conditions is something we’ll need to look at more closely over the next few years as it looks like we’ll be seeing more of the same.

For me it can mean producing quality bales, not so much for the shoulders of the year, but to fill in the summer gaps. Also, I guess my pregrazing covers were too low.

Mike Dineen spoke at the Teagasc Dairy Conference on optimal pre-grazing coverage of 1400-1600 kg DM/ha to get the most out of grass in terms of dry matter and energy intake.

When I got home I checked mine on Pasturebase and they were too low, especially during peak grazing season.

Average yields before mid-season grazing were 1128 kg DM/ha. This affects both the intake and the overall yield of these paddocks.

I was concerned that the clover paddocks newly sown in 2021 would not perform, but when we looked at the Pasturebase data I was pleasantly surprised. The grass yield on the clover paddocks reseeded in 2021 was 12.7 t DM, with only 54 kg N/ha compared to 12.8 t DM on the sods, which received 232 kg N/ha.

Progress has been made in reducing my dependence on chemical N by ensuring soil fertility is optimized. I applied 360t of lime this year – an average of 3.2t/ha – and I didn’t start from a low base.

Lime is really important to me and it’s the starting point (and a cheap start) for reducing my dependence on N.

I had my manure analyzed last spring to help me make informed decisions about how best to use it. It analyzed at 4.7 units N per 1,000 gallons.

This equates to 9-10 units for the entire group of Lakeland Signpost Farmers.

I applied 3,000 gallons of manure and only applied 15 units of N. I now know I need to top this up with chemical N to get 23 units/ac.

I planted new hedges in 2022 to improve biodiversity on the farm and will do more in 2023. But I will approach it differently:. I’ll do it before calving starts and have a contractor do it instead of doing it wrong myself.

For example, I didn’t use a membrane around the plants so I ran into the problem of having to physically weed the area.

In general I believe that there is no financial incentive to improve biodiversity on my farm and this needs to be taken into account if farmers are going to do this in the years to come.

Dermot Heaney farms at Kilberry, Navan, Co. Meath