FYM or digestate solids?

[Wobblebox]

I’ve been doing amuck for straw deal with local pig farmer for a while now and he has just been approached by a local-ish AD plant which should hopefully be commissioned by Oct, they asked him if he’ll supply the AD plant with muck and we’d get the separated solids back.
The small benefit to me is that we won’t have to pay any haulage, we currently haul the pig muck ourselves.
But my concern is, what would I loose from nutrients and OM?
The pig farmer has said he isn’t bothered where it goes as long as his muck get shifted regularly, I take it from that he isn’t getting paid for the muck either.
He also suggested that if I ‘helped’ the AD plant then I could be able to take liquid digestate too

 

[teslacoils]

I've no experience of ad solids, but the perk to me from liquid digestate is it goes on via the tramlines in spring, so it all gets in the crop.

Suppose in an ideal world, you chop the straw and get the juice. Not that that helps the pig man. There's naff all fibre in the liquid. Well, not enought to really count.

 

[d williams]

I’ve been doing amuck for straw deal with local pig farmer for a while now and he has just been approached by a local-ish AD plant which should hopefully be commissioned by Oct, they asked him if he’ll supply the AD plant with muck and we’d get the separated solids back.
The small benefit to me is that we won’t have to pay any haulage, we currently haul the pig muck ourselves.
But my concern is, what would I loose from nutrients and OM?
The pig farmer has said he isn’t bothered where it goes as long as his muck get shifted regularly, I take it from that he isn’t getting paid for the muck either.
He also suggested that if I ‘helped’ the AD plant then I could be able to take liquid digestate too

So does that mean you can charge for your straw and also charge the ad plant for disposal or spreading of their waste ???

 

[sjt01]

I’ve been doing amuck for straw deal with local pig farmer for a while now and he has just been approached by a local-ish AD plant which should hopefully be commissioned by Oct, they asked him if he’ll supply the AD plant with muck and we’d get the separated solids back.
The small benefit to me is that we won’t have to pay any haulage, we currently haul the pig muck ourselves.
But my concern is, what would I loose from nutrients and OM?
The pig farmer has said he isn’t bothered where it goes as long as his muck get shifted regularly, I take it from that he isn’t getting paid for the muck either.
He also suggested that if I ‘helped’ the AD plant then I could be able to take liquid digestate too

P and K will come out of the digester just as they went in. Nitrogen can be lost as ammonia from the digestate, as it is high pH. I am not sure what the pH of pig muck is, but the losses are probably comparable. You might lose a bit of sulphur, depending on how the reactor is run.
We are now acidifying our digestate to stop the ammonia loss, I have not had the final analysis done but I think we will have about 25% more N than untreated.

 

[cowboysupper]

P and K will come out of the digester just as they went in. Nitrogen can be lost as ammonia from the digestate, as it is high pH. I am not sure what the pH of pig muck is, but the losses are probably comparable. You might lose a bit of sulphur, depending on how the reactor is run.
We are now acidifying our digestate to stop the ammonia loss, I have not had the final analysis done but I think we will have about 25% more N than untreated.

Have you a link to the system you use to acidify the digestate?

 

[Chae1]

Personally I would rather have the pig muck than digestate fibre.

Will need spinning disc spreader to put on digestate fibre if it's like stuff we put on.

 

[sjt01]

Have you a link to the system you use to acidify the digestate?

Not written it up yet, I have done a few presentations on progress, but am waiting for some analyses to be done before I document it. Happy to demonstrate it if you are in Norfolk anytime. This is what I have been working on as a batch process.

 

[robbie]

Personally I'd say take the pig muck but if the AD really want it and you can work a deal to get the solid and some liquid, which personally, I think you need to equal good pig poo then let them have the poop.

 

[teslacoils]

Suppose a lot depends on nutrient use. Our spring digestate gives c140kg of available n. I'm not sure a "full dose" of autumn pig poo is as good. Unless your land is k for spring spreading / ploughing.

 

[deleted user 837354]

Personally I would rather have the pig muck than digestate fibre.

Will need spinning disc spreader to put on digestate fibre if it's like stuff we put on.

What is the consistency of digestate solids? If it spreads nicely and is totally free of plastic and other debris I would be very keen. Does it smell much?

 

[Chae1]

What is the consistency of digestate solids? If it spreads nicely and is totally free of plastic and other debris I would be very keen. Does it smell much?

It's really fine. Light stuff. Contractor said he only gets 4t in a 14t spreader. Doesn't smell that bad. Got about 800t in our yard at the moment for putting on stubble after harvest! Mushrooms growing on pile. Not sure if that's a good thing.

 

[sjt01]

The big advantage of digestate over manures is the consistency. It has been stirred up in a big tank for 50 or so days, so will be far more even than raw manures. That means you can trust the analysis to a greater extent.

 

[Hawkes]

We have had digestate liquid and solid. The solids come wet so weigh a fair bit to haul it. I get it free but have to pay for collect / delivery. I take it over time and build up a good heap. I then watch it disappear as it settles down to about half the volume and the weight too. It spreads evenly and have used rear rotor spreaders and a rotaspreader on occasion, all work fine. The jury is still out here on how much good it does compared to fym. It is easy to handle and doesn't smell too much.
I get an analysis sheet, but whether it is fact or fiction hard to tell.