Slurry and farmyard manure are valuable resources.
They contain nutrients and organic matter that can be returned to the soil, but the value a farmer gets from them depends heavily on how they are stored, handled and applied.
At this time of year, that becomes particularly important.
As rainfall increases, soils become wetter and grass growth begins to slow, the risk of losing nutrients through run-off, leaching or gaseous losses can increase. Teagasc highlights careful autumn management of organic fertilisers as particularly important as farms approach the end of the spreading season.
So the question is not simply:
“How much slurry or FYM have I got?”
It is:
“How can I make the best use of what I already have?”
Slurry and FYM are nutrient resources
Slurry and farmyard manure should not simply be viewed as waste that needs to be moved out of storage.
They contain valuable plant nutrients.
The actual nutrient content, however, can vary substantially according to livestock type, diet, bedding, storage, dilution with water and other factors.
AHDB therefore recommends analysing representative samples where greater accuracy is needed rather than assuming every load has the same nutrient value.
That gives farmers a much clearer idea of what nutrients are already being returned to the land before deciding what additional fertiliser may be required.
Timing can affect how much value you retain
Spreading is not simply about finding an empty day in the calendar.
Soil conditions, rainfall, crop demand and the time of year all influence how effectively nutrients are used.
Organic materials applied when crops are actively able to use their nutrients generally offer a better opportunity for nutrient recovery than applications made when plant demand is low.
Heavy rainfall following autumn applications can also increase the risk of nutrient movement through or across the soil.
That means timing slurry or FYM applications should form part of the overall nutrient plan rather than being driven purely by the need to empty a store.
Look at the field before the tanker
Before spreading, look at the condition of the ground.
Ask:
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Is the soil already saturated?
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Is water sitting on the surface?
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Is significant rainfall forecast?
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Is machinery likely to cause rutting or compaction?
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Is there sufficient crop or grass demand?
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Are there areas where run-off could reach drains or watercourses?
Spreading organic manure onto waterlogged or unsuitable ground can increase environmental risks as well as reducing the value retained within the farming system. Current rules differ between Ireland and the UK, so farmers should always follow the regulations applying to their own location and farm.
Application method matters too
How slurry reaches the soil can influence how much nitrogen is retained.
Low-emission slurry-spreading systems are increasingly used to place slurry more directly onto the soil and reduce contact with the air compared with traditional splash-plate spreading.
Teagasc's guidance emphasises managing organic fertilisers to maximise nutrient use while reducing losses to both air and water.
The aim is straightforward: retain as much of the nutrient value as possible for the crop rather than losing it during application.
Don't overlook FYM
Farmyard manure works differently from slurry but is equally worth managing carefully.
Its nutrient content varies according to factors including livestock type, bedding and how long the manure has been stored.
FYM also contributes organic material to the soil.
That means its value is not only about the nutrients available to the next crop.
Organic matter forms part of longer-term soil management, influencing soil structure, water movement and the wider soil environment.
AHDB guidance also shows that the amount of nitrogen available from FYM varies according to application timing and management.
Think about storage as part of nutrient management
Good slurry management begins before spreading.
Storage capacity gives farmers greater flexibility to apply slurry when conditions are suitable rather than because the store simply needs emptied.
That can make it easier to match applications with crop need and more favourable soil and weather conditions.
The same principle applies to FYM.
How and where manure is stored can affect both nutrient conservation and the risk of losses to the surrounding environment.
Watch Rob explain how he used Humusoil in his FYM heap
What about slurry and FYM additives?
Additives are increasingly discussed as part of slurry and manure management.
But they should not be viewed as a replacement for good management.
Before adding anything, it is worth asking:
What problem are we trying to solve?
What is already happening in our slurry or manure system?
How will this fit with the way we currently spread and manage nutrients?
A product should complement good storage, timing, soil management and nutrient planning rather than being expected to compensate for problems elsewhere in the system.
Where does Humusoil fit?
Humusoil contains humic acid, seaweed and beneficial soil microbes.
For farmers, it can be applied directly to land or incorporated into existing farm practices, including application with slurry, bedding or farmyard manure.
That can allow Humusoil to be introduced through a spreading system farmers are already using rather than requiring an entirely separate field operation.
The aim is not to replace slurry, FYM, fertiliser planning or good agronomy.
Humusoil is intended to form part of a wider soil-first approach, alongside the organic nutrients and organic matter already available on the farm.
Make better use of what the farm already produces
Slurry and FYM represent nutrients that have already entered the farming system.
Managing them well means thinking about:
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nutrient content
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storage
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application timing
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soil conditions
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weather
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application method
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crop and grass demand
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soil structure
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the other inputs being used alongside them
There is no single product or management change that will maximise the value of every load.
But small improvements in how organic manures are handled and applied can help farmers make better use of resources they already have.
Before the next tanker or spreader heads for the field, it is worth asking:
Are we simply getting rid of slurry and manure — or are we managing them as valuable farm resources?