Looking for advice to compost fine sawdust with fish emulsion or urea

Dear Permies.

I have free access to sawdust ( pine or eucalyptus) and fresh fish guts from the fishermen.
I know that swadust can take an eternity to break down if it is just sitting around.
I still have a bag of urea at home but I would prefer to make fish emulsion (including effective microorganisms) and mix it with the sawdust to turn into nice, fine and nutritious compost.

Maybe it makes sense to add some aglime too?

Which amounts do I need to get the carbon nitrogen ratio right?

What amount of nitrogen would a fish emulsion probably have?

What would be the best way to to calculate for the right amounts of fish emulsion and sawdust? volume or weight?  (i am pretty bad with mathematics but willing to improve)

I would simply compost in a pile that I may have to turn sometimes.

What would you recomment?

I will post updates about the process, once started ( we a buildig an extension of our house right now, so it might take some time)

Looking forward to hear from you guys.

Howdy,

I thought this posting covered sawdust/compost really well.


https://permies.com/t/6369/sawdust

I also have a book,  the Humanure Handbook, and he also discusses sawdust/urine recipes. Pine sawdust may have a pitch content that may make it harder to breakdown. Urine, high in nitrogen, collected in/on sawdust, breaks pile down, and keeps pile moist. Temperature, pile damp not soaked, are part of the "recipe".

For me and my clay soil, I have piles of sawdust(all kinds,pine,fir,oak, from firewood cutting and woodwork) around my garden that I pee on, so as not to lose the nitrogen content. I think I would be most concerned about the smell of fish parts attracting unwanted critters(my dogs,bears,dogs keep bears away}.

I am not an expert, just that book got me started on compost pile creation and not just composting human waste, but understanding how to make compost piles "work". There is a lot of info here on permies, thats why "we" love it. My system is "simple".  

What about just composting the fish guts with the sawdust? Making fish emulsion sounds like an extra step to me. But maybe there's some benefit that I don't know about?

Thank you guys for the input.

The idea of making fish emulsion first was to have it alredy more broken down and therefore less smelly and easier to mix with the sawdust.
No Bears here just dogs that need to be fenced off.... And flies ( i once dumped 25Litres of fish guts into an underground wood compost and had an invasion of flies bevore I could quickly cover everything up with sand.  Incredible! I didn't know where they all came from in just a minute.

I found an interesting article on this topic

https://www.canr.msu.edu/news/dont_throw_away_that_fish_waste

Now I switched my thinking from "making sawdust compost with the help of fish" to "composting fish guts with the help of sawdust" (same same but different)
Creating less, but more fertile compost in an enclosed system like a turning barrel or two well closed compost boxes ( so I can shovel it from A to B)
Always covering the Pile with a layer of smell blocking material like ready compost, earth, sawdust or biochar (got a lot of it).

I will purchase the humanure book for shure as we will have to build compost toilets for our new home in the near future.

Thanks once more.

If you can invest on a chum grinder or a meat grinder.  This will allow you to more fully mix the sawdust and fish leftovers.  Are you getting guts from gutted fish or the leftovers after they are fileted?  If the former then meat grinder is fine. If the latter than a chum grinder would work better.  Any large heads can be buried whole in your tomato beds or corn beds a few weeks ahead of planting.  Smaller heads and bones will be ground up fine by the chum grinder

Hi! I also have access to tons of sawdust and would like to use that as a (thin) mulch, because I think little seedlings would come up well through that because it is so lightweight, without the soil drying out while waiting for them. I figured I could simply give diluted urine to all the places which I covered in it while watering anyway to prevent nitrogen loss. Do you think this is as easy as that? Is there any way to figure out how much urine is needed to be sure? Has anyone done that?

I'm gonna suggest chickens.
I think they could do a fine job eating the guts, mixing the sawdust up with the guts and eating any insects attracted to the compost.

Tomke Roolfs wrote:Hi! I also have access to tons of sawdust and would like to use that as a (thin) mulch, because I think little seedlings would come up well through that because it is so lightweight, without the soil drying out while waiting for them. I figured I could simply give diluted urine to all the places which I covered in it while watering anyway to prevent nitrogen loss. Do you think this is as easy as that? Is there any way to figure out how much urine is needed to be sure? Has anyone done that?

I have found that applying sawdust directly is problematic. Even a thin layer can pack into a "thatched roof" that sheds rain and impedes air exchange with the soil below. In fairness, this may not be a big issue in a wet climate.

Personally, before applying, I would put it through a rough composting process -- mixing it with coarse plant material, char, and all the nitrogen I could produce (raw greens or "Vitamin X"). And I would still watch out for the thatched roof effect after applying. My 2c.