Composting with pig slurry...


Arable Farmer
I'm an arable farmer but have access to pig slurry from next door farm over the hedge.
We are moving into a regenerative farming system and I was hoping to compost a proportion of this pig slurry.
Anyone have any experience of this?


Slurry would have plenty of N but you'll need a source of carbon eg. green waste, straw etc.

Would obviously have to mix and not end up with a wet anaerobic heap as composting is aerobic decomposition/stabilisation.

Need to turn the heap to oxygenate the heap as the O2 allows the microbes to do their stuff.

How to deal with the slurry on site would be a big question.

Environmental Permitting requirements to look at aswell.

Maybe add a large concrete pad with water collection pits to your new farmyard wish list.


Composting a liquid would be quite hard I'd imagine.

What kind of slurry are we talking about exactly? What size of pig (grower/finisher, sow, both)? What kind of shed? Straw bedded scrape-through, or slatted?

If the latter shed, the DM will be less than 10%. Mixing that with straw or whatever to get something stackable and aerobic would take a lot of straw. Not sure what the C:N ratio would be...
If you separated it, the solid fraction would stack better, and may be aerobic enough to compost well, but not sure what the C:N ratio would be. But you have to separate it, which costs. And the volume reduction of the liquid fraction is minimal by all accounts, so you still have a load of slurry to deal with.

Our neighbour takes wood chippings from the local tree surgeon. They clearly don't rot down on their own, so last time we spread slurry he took a couple of tanker loads of slurry to add to the pile. Not sure it'll work, but I might just call him to find out now.

Fwiw, coming at this from a regen angle, the least-worst thing to do may be to dribble bar the slurry directly onto your crops at a low rate. It'll certainly add fertility to your land, and if the rate is low enough you'll probably avoid many of the risks sometimes associated with slurry (bacterial dominant, low aerobic soils, worm kill etc).
Obtain or buy a tanker with the same width dribble bar as your tramlines and apply pig slurry to your crop the second it is dry enough in spring. You won't look back. In time you may be able to drastically reduce your use of P and K and probably curtail your use of bought in nitrogen, too.

Just do not over apply any kind of liquid to your land. Little and often is best.

There is no need to compost slurry, it has minimal fibre content and composting it just means you will be losing any readily available nutrients from it.


Once got involved in clearing a very badly run free range chicken unit out , the muck was damn near slurry with water ingress and badly adjusted drinkers .

My plan was to mix the slurry with a large stack of straw horse manure using my 360 but it never really mixed , you just got pockets of snot ,dry straw or slurry ,even leaving for 3 months it never really soaked in .

Would definitely go along with Honeybadgers idea


Spend some time googling around 'Joe Lopez Real', 'Controlled Composting Systems, Wye College'.
Loads of work was done on this in the 90's, damned shame that much of it has probably never been put online. There will be people on here who did their phd with Joe, composting pig slurry mixed with all manner of organic wastes.


i do believe that @puntabrava has tried mixing sludge and also has a massive tanker to get slurry onto crops
Thanks David.
You may need to bale the straw and dose it with the slurry and then turn then dose with more slurry to gain a product that will enhance your soil/ organisms/ worms. I defer to @Barleycorn far superior knowledge to mine on the subject.
Thanks David.
You may need to bale the straw and dose it with the slurry and then turn then dose with more slurry to gain a product that will enhance your soil/ organisms/ worms. I defer to @Barleycorn far superior knowledge to mine on the subject.
View attachment 924740

I presume with your tanker you are applying slurry to growing crops from the tramlines most springs? Has anyone quantified the saving they are making on N, P or K?

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Man fined £300 for bonfire-related waste offences

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Written by William Kellett from Agriland

A man has pleaded guilty at Newtownards Magistrates’ Court to waste offences relating to a bonfire next to the electrical sub-station on the Circular Road in Newtownards, Co. Down.

Gareth Gill (51) of Abbot’s Walk, Newtownards pleaded guilty to two charges under the Waste and Contaminated Land (Northern Ireland) Order 1997, for which he was fined £150 each and ordered to pay a £15 offender’s levy

On June 25, 2018, PSNI officers went to Gill’s yard, where they found a large amount of waste consisting of scrap wood, pallets, carpet and underlay.

Discussion with Northern Ireland Environment Agency (NIEA) officers confirmed the site...