NPK of cow manure?

[Elizabeth C]

Hello,

How can I get a pretty good idea of the NPK of the cow manure I’m using from a friend? One source I saw says cow manure has a 3-2-1; another says .06-.04-.05. That’s a pretty big difference, and I need to make sure I get enough because of what my soil test recommended.

Thanks!

 

[Chuck]

It all depends on where and what the cow manure came from. A range cow grazing on grass will have a lower npk than will feedlot manure. By far the manure with the highest numbers comes from feedlot cattle being fed a mixture of alfalfa and corn but this is mainly for fattening in custom feed lots. These manures will have an npk of about 5-3-2 Most bagged manure is from feedlots but not all feed alfalfa and corn. Many feed coastal bermuda or other hays and grains such as cottonseed meal. These will be close to the 3-2-1. If your friend feeds his cattle then the NPK will be closer to 3-2-1 but if the manure comes from just grazing it will be less. Composted manure as with all composts has a significantly lower npk and this is where you get the .06-.04.-05 numbers. So, to make a long story short, there is no positive npk number for any manure, only basic averages.

 

[YumYum]

The other animal manures are the same way as I'm sure you realize.

 

[Meadowlark]

As an aside, be sure you ask your friend if any herbicides were used on the fields(hay) the cows grazed(fed) on.

 

[Elizabeth C]

It all depends on where and what the cow manure came from. A range cow grazing on grass will have a lower npk than will feedlot manure. By far the manure with the highest numbers comes from feedlot cattle being fed a mixture of alfalfa and corn but this is mainly for fattening in custom feed lots. These manures will have an npk of about 5-3-2 Most bagged manure is from feedlots but not all feed alfalfa and corn. Many feed coastal bermuda or other hays and grains such as cottonseed meal. These will be close to the 3-2-1. If your friend feeds his cattle then the NPK will be closer to 3-2-1 but if the manure comes from just grazing it will be less. Composted manure as with all composts has a significantly lower npk and this is where you get the .06-.04.-05 numbers. So, to make a long story short, there is no positive npk number for any manure, only basic averages.

Thanks so much, that’s really helpful!! I’ll ask what he feeds it. Also it’s composted; so would grass-fed, composted cow manure be close to those low numbers I mentioned?

 

[Chuck]

Thanks so much, that’s really helpful!! I’ll ask what he feeds it. Also it’s composted; so would grass-fed, composted cow manure be close to those low numbers I mentioned?

Yes, and if you can incorporate dried but uncomposted manure into your soil you will get better NPK numbers but the compost is still good stuff. It will make a terrific soil amendment.

 

[Elizabeth C]

Thanks!

 

[Elizabeth C]

As an aside, be sure you ask your friend if any herbicides were used on the fields(hay) the cows grazed(fed) on.

Would that change the NPK too?

 

[Meadowlark]

No, but it would/could ruin your garden for growing plants for several seasons. Do a search on "gardens and herbicide use in manures."

 

[Elizabeth C]

No, but it would/could ruin your garden for growing plants for several seasons. Do a search on "gardens and herbicide use in manures."

Pretty sure there are no herbicides because he uses it for his organic garden which does really well.

 

[DirtMechanic]

I think it's a really horrid idea for multiple reasons, but fans of reformulated manure into feed use an important point about manure to make their case. In this quote they were testing feedlot manure about proteins which are made of the amino acids so useful in the organic garden you mentioned. Look at the percentages.

"Total nitrogen of all samples averaged 3.67 percent (or 23 percent crude protein on an ashfree basis) and protein nitrogen represented 65 percent of total nitrogen. Crude fibre content of rations varied from 6.5 to 27 percent and was reflected in the crude fibre content of the manure."

I think the proteins in manure are the real gem. But careful, the antibiotic resistant fungal elements as well as bacterial elements are also emerging in manure from commercial farm practices. One the the reasons I could never see recycling manure protein back into feed of any kind. Same is true of butcher scraps being recycled. Prions and all that problem Europe had before they (I think) banned the practice.