Composting Grass Dairy Manure

by Jimmy Elizondo
(Brownsville, TX)

I'm trying to make compost out of grazed dairy manure, and have been told not to use other materials as the cows are grass fed. Should I use grass clippings or other another carbon source?


The operation is in the tropics and already started with around 100 tons. It is going to be used on grazed Bermuda grass with a compost tea extractor.

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Dec 17, 2011
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Grazing and the dung beetle factor
by: Anonymous

Do not use continuous parasiticide in the feed. Rather deworm cattle twice a year, keep them in an enclosed area for a few days until the dewormer passes, then turn them out to pasture. The dung beetles will bury/compost the manure for you. The pasture will benefit with a lot less work and expense.

Dec 17, 2011
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Composting Cow Manure
by: Compost Junkie Dave

Hey Jimmy,

Is the material that you're wanting to compost pure cow manure, or is it cow manure + bedding?

If you're using straight dairy cow manure, you're going to want to add something with a little bit more carbon to the mix. Straight cow manure tends to have a composting carbon nitrogen ratio of approximately 20:1, and the ideal ratio is closer to 25-30:1. Adding a carbon source will also bulk up your compost, resulting in better aeration and a larger quantity of the finished product. So if you have access to dry grass clippings and/or straw, I'd recommend adding these to your compost recipe.

If you're using dairy cow manure with bedding, there is a very good chance you'll be able to make a great compost from this ingredient on it's own.

As for the post made by Anonymous, he/she is right on the money...if your situation allows for it. If you can "compost on the spot" while harnessing the power of dung beetles, that is a very viable option.

Great idea re the quarantine period after de-worming Anonymous. Thanks.

Here's a fun fact from an article in the journal BioScience - "According to the The American Institute of Biological Sciences, dung beetles save the United States cattle industry an estimated $380US million annually through burying above-ground livestock feces." Isn't nature incredible when we don't intervene?

Dec 18, 2011
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Dairy Cow Manure
by: JIMMY ELIZODO

Hello, thank you for your comments. The manure is from my cows that eat very little concentrate (4 lbs of rice polishings) and graze on grass with Leucaena for the rest of their intake.

When they graze, I favor the dung beetles, but in the winter I feed them some green corn after they take the cob off. This is when we accumulate cow manure for composting. This occurs over a 90 day period.

The compost turned up well in some places of the row and seemed to lack aeration in other places, so I guess it needed more carbon and more frequent turning. It also didn't help that we experienced quite a drought this year.

Regards, Jimmy

Dec 19, 2011
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Cow Manure Compost
by: Compost Junkie Dave

Thanks for the update Jimmy.

From the information in your post, it sounds like you're accumulating straight cow manure (i.e. no bedding mixed in), is that correct? Typical tie-stall set-up?

I'd have to agree with you, and say that the variation in the quality of your finished compost was probably due to infrequent turnings and lack of moisture. Did you happen to read our recent interview with Tim from Humble Acres Organics? If not, he said he tends to use 5,000-6,000 gallons of water per half-day during the initial stages of his composting process. Now I don't think you're making compost on the scale that he is, but there is definitely a need for additional moisture when composting.

Do you have any pictures of your finished windrow/pile? If so, we'd love to see them. If you have trouble uploading them, send them to me via our contact us page, and I'll upload them for you.

Looking forward to hearing from you, and anyone else who'd like to chime in on the topic.

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