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High Fertiliser Prices, Where to now?

At this stage we are all aware fertiliser prices, in particular nitrogen, has increased dramatically in the last 6 months. So, what's the advice to overcome this dramatic change? Austin Callaghan, Drystock Advisor, Teagasc Claremorris has advice on when to spread, take stock of slurry, lime and more

Fertiliser is an input that farmers see as very expensive and many would prefer spending this money on meal.  The truth is that meal is very expensive for the return it provides.  One tonne of meal provides approximately 850kgs of dry matter material.  Meal is in the region of 15% water.

A 50kg bag of CAN at 27% Nitrogen contains 13.5kgs of nitrogen. Therefore in 1 tonne there are 270kgs of nitrogen. At peak grass growth the response to chemical nitrogen applied is; 1kg of nitrogen can grow up to 50kgs of grass dry matter. One tonne of CAN nitrogen could therefore grow 13500kgs of grass dry matter or 13.5 tonnes of Dry matter.

So, compare 1 tonne of meal today costing €350 where you are buying 0.85 tonnes of dry matter with nitrogen at €720 per tonne that can grow 13.5 tonnes of dry matter.  Of course this is when you get peak response.  In early spring and later in the year the response to nitrogen could be a quarter of this.  Similarly in poor growing situations where the weather is poor the response to nitrogen is considerably reduced.

When analysing farm profitability, in many instances it’s the high meal usage on farms that’s problematic.  It is not the cost of the fertiliser purchased. This is not case on farms where excellent grassland management is practiced and meal inputs relative to farm output are already low.

This will now change as the price of nitrogen has increased by approximately 250%. If these high fertiliser prices are to last for a number of years it will have big implications for farming in Ireland.

So what is the advice or options?

When to spread?

In most years, the best response to fertiliser is when grass growth is at its peak from April onwards. Fertiliser applications should coincide with this. Spread fertiliser from mid-March onwards, fertilising silage fields in early April. On colder heavier soils spread 2 weeks later.

Slurry Application

Slurry is a valuable source of nitrogen.  Slurry applications should also coincide with the onset on good grass growth. Ideally apply slurry from March onwards. Each 1000 gallons can supply 9 units of nitrogen. An application of 3000 gallons can provide 27 units of nitrogen, equivalent to a bag of CAN. Slurry spread in late January will not provide these units. Why waste this valuable nutrient? Slurry is also a very good source of P & K and for this reason, slurry should be spread on silage fields prior to closing.

Low Emission Slurry Spreading

Slurry spread in very warm dry weather conditions loses nitrogen to the atmosphere. For this reason you should use low emission slurry spreading (LESS) equipment to spread slurry. This will increase the nitrogen recovered from the slurry compared to the traditional splash plate.

Slurry Application Rate

Take care when using the dribble bar or the trailing shoe not to apply this slurry at a high application rate. Forward speed of the tractor needs to be increased when using this equipment as we’ve come across cases where slurry has been applied at over 4000 gallons per acre. This can have implications later for silage preservation.


Where soils are acidic, chemical fertilisers or organic fertilisers (slurry / FYM) will not function to their maximum. The response to the nutrients applied will be reduced. In addition acidic soils reduce the availability of many of the essential nutrients as they are bound to clay particles in the acidic soil. Also the breakdown of organic matter (decaying grass / grass roots / slurry) is reduced in acidic soils.

Soil type

The response to all applied fertilisers is much lower on poor soils, peat soils or heavy poorly drained soils. Only apply fertiliser to these fields in very good weather conditions. In the situation where the farm has a low stocking rate consider not fertilising these fields in 2022.

Stocking rate

On most farms much of the fertiliser is applied to the silage fields. In 2022 on lowly stocked farms consider not fertilizing the grazing fields. To ensure adequate supplies of winter fodder silage fields need to receive appropriate fertiliser applications. Chemical nitrogen applications can be reduced where slurry is applied as described above.

Paddocks / Rotational Grazing

If farmers put a rotational paddock system in place their farm will grow more grass without any additional fertiliser inputs. Ask any famer who has put a paddock system in place and the problem they have is they have too much grass. In this scenario where grass growth exceeds demand some fields can be cut for silage.

There is no denying the high fertiliser prices will provide a huge challenge in 2022. There is scope to reduce the impact if you plan now. The response of some famers is to immediately cut stock numbers. This may not be a good solution as farm output will be reduced. Farms with low output have great difficulty generating positive net margins.

You might also like to read the Teagasc Protected Urea Factsheet

Teagasc Advisors are regular contibutors of articles of interest to farmers here on Teagasc Daily.  For advice on fertiliser and slurry applications contact your nearest Teagasc office here