Research: Cost of additional slurry storage potentially €800/cow

Farmers are being urged to “maximise slurry nutrient use” by having adequate slurry storage and only spreading it at optimal times.

According to Teagasc this will also “have a knock-on effect of improved water quality” while maintaining grass growth.

Slurry is a valuable nutrient on farms, and the importance of it on farms has become increasingly more important in recent years.

The need to become more sustainable and reduce the amount of chemical fertiliser has led to many farms looking to increase the efficiency of the slurry they spread.

Teagasc research suggests that slurry spread in the correct conditions has a value/cow of €64, while spreading in the wrong conditions has a value of €21/cow.

This means that slurry spread at the optimal time is worth an additional €43/cow by using the nutrients it contains to grow grass.

For this to be on many farm the amount of storage available would likely need to increase and to some extent the hand of some farmers may be forced.

The Department of Agriculture, Food and the Marine (DAFM) has requested Teagasc to complete research on whether the current 0.33m³/cow/week requirement for farms is accurate.

It appears likely that the figure is going to increase by around 20%, which would mean that the storage requirement on many farms will not be met.

Slurry storage

For some time, chemical fertiliser made up for the less the ideal use of slurry on farms, but as chemical fertiliser allowances drop, slurry become more and more important.

Along with the benefits that can be achieved from growing grass with slurry spreading at the right time in the right conditions is the positive impact it has on water quality.

Issue with water has seen the nitrates derogation maximum stocking rate reduced from 250kg of organic nitrogen(N)/ha to 220kg of organic N/ha in many areas.

Investing in slurry storage can be a significant investment, cost and figures should be done on every farm before decisions are made.

Patrick Gowing from Teagasc has outlined the potential cost of investing in slurry storage for 200 cows for 20 weeks.

Gowing said that if you look at the cost of additional slurry storage, the upfront capital cost is €800/cow excluding value added tax (VAT) and any potential grant.

While this is a significant cost, if you average the cost over a 20-year lifespan of the tank, it will cost €20/year.

He noted that there is a saving of €43/cow by spreading slurry at the right time, which will have a knock-on effect of improved water quality while maintaining grass growth.

Challenging spring weather is making it increasingly more difficult to get slurry out in the spring and there is also the issue of the conditions not being optimal.

On many farms, slurry storage can be described as ‘tight’ and investing in slurry storage may be needed.