I think dry manure has lost about 60-80% of nitrogen from urea volatilization. That is, once it dries out, the remaining urea just crystallizes. So there is some left. I'm inclined to believe, however, that you won't be risking burning anything if you add it directly to soil, especially as a dressing well before planting. Certainly with regard to fibrous material, it would be an excellent addition, benefiting the soil structure.

You could always do a test to see if it has any 'green' action left in it. Pile up a wheelbarrow or two, wet it down well and wait for a couple days. Is it smelly or hot? If not, you can use it however you want. If so you probably ought to compost it.

If it has aged more than a year - covered or not - it is perfectly safe to use anywhere in the garden. Three plus years should be plenty long enough.

Ok, thanks. I figured just the fiber it it would be a good thing- I'm losing some tilth, but had wondered how nutritious it woud be otherwise for the bed. If it loses that much nitrogen, I'll plan to up the nitrogen a bit more when I dress the bed before fall planting.

I just did my big garlic pull, and between the dry and probably a need for dressing, the bulbs were underpar this year. So I got a patch of dry beans in now and some clover to sprinkle in once the last garlic is done, and once the beans and clover are done I'll dig in that horse dung along with some other amendments before garlic planting time comes.

I was a bit more concerned that it would be so useless it would be better off as browns in the compost bin rather than of use in the garden directly.

"If it loses that much nitrogen, I'll plan to up the nitrogen a bit more"

Horse manure doesn't have all that much nitrogen to begin with. You would likely need to supplement anyway if you are relying on just the manure as a nutrient source. It is just that fresh manure offers N in a very fast acting, "hot" form (mostly as urea) that can burn fine roots. Aged manure still contains N but in a different form that takes time to break down.

I know the wet/fresh aged value of horse manure is, just was rather unsure of what dry aged manure is worth directly in the garden.

Well, letting manure dry out and sit for a long time doesn't really "age" it. Aging manure is pretty much composting it. Keeping it wet and letting it decompose. But if you let manure dry out before the urea is all volatilized, some will still be there. In this case, you really don't have a clue about whether there is any urea left in your dry manure, but there certainly could be. As noted, wetting it down and sniffing is probably the best test.

Also, as noted, manure doesn't have much long-lasting nitrogen. The urea is a wham-bam kind of thing. So planning on lasting nitrogen amendation with urea is probably not smart. Best bet to incorporate nitrogen from the manure urea as much as possible is to dig it in deeply.

Aging manure is exactly that!! It is allowed to sit untouched - either covered or uncovered - for a period of time, At least 6 months before use but preferably 12+ months. Some decomposition is obviously taking place during this period but not enough for the end product to be considered "compost". And covered, dry manures are likely to convert and volatize urea rapidly - 3-4 months - so minimal risk of 'burning'.

The point is, 3 year old manure is perfectly safe to use in the garden without risk of excessive N or urea burning plant roots.

"Aged manure" is commonly understood to be decomposed manure. Allowing it to dry out won't accomplish that. If you dry manure quickly by baking it, it is not at all decomposed. Now, it is a little simplistic to consider it to be "composted", in the sense that composting can be thought to subject the material to high temperatures. Aged manure need not be heated much at all. So aged manure need not be sterile. Now, urea simply won't volatilize in a dry medium. It just crystallizes. If dry urea volatilized, your bags of urea wouldn't have anything in them. Urease, which is the enzyme that breaks down urea, is carried to it in the water.

But it takes some time for manure to dry out completely and, as noted, most of the urea in it has, by that time, probably volatilized. So I'd agree that it is probably safe to apply directly to soil that plants are growing in.

Do the nose test to be sure.

Not to start any arguments about composting but the most important reason to compost is to kill pathogens. Fecal coliform such as E-coil require a temperature over 130 degrees for about a week but many fail to achieve this temperature when composting. Time and temperature is not reliable which will vary based on cell count and studies show most small scale composting fail to kill all E-coli using temperatures alone when used to soon. The only reliable way to kill 100% of fecal coliform is through diverse microbial action and temperature isn't very important as long as it happens above 55 degrees over a period of time of at least 6 months but preferably 12 as garden gal said.

E-coli can survive in manure up to 6 months, wet or dry and why we have E-coli outbreaks because manure sits around, used to early and isn't property composted to make it pathogen free. Based on science, Manure sitting on a floor and not in a compost pile for a couple of years is perfectly safe from pathogens, unless over the years up until last night rodents used the area as a toilet and added they're own fecal coliform to the piles. Because of this I wouldn't use it on cole crops this year but a garlic bed for next year? no problem.

Lots of good points here. For more information, Susanne von Rosenberg, UC Master Gardener of Napa County, wrote a very helpful article this year titled Manure--Gardener's Gold that goes into how to use manure, the difference between aging and composting manure, and the types of pathogens to watch out for in different types of manures.

To reduce viable seeds I prefer composting manure from animals that grazed pasture. Since this is going on food crops and has some unknowns,I'd do as Tox suggested and depending on results,compost or use as worm bedding.

I'm in the camp that says the risk is pretty low and unless you're in a vulnerable group, you should be okay with horse manure that's been out for ages. But personal choice of risk tolerance.

E coli is everywhere, concentration matters, and horse manure in a small operation is unlikely to be an issue. The long aging will reduce the concentration. Fresh manure from large cattle operations is a different risk profile.

That said, there's no sterile manure or soil. Wash well. Apply well in advance of harvesting. Garlic you add for cooking is different than eating garlic greens or bulbs straight from the garden.

I've been using aged horse manure that is very old, possibly 15 years old and find there to be no problem. However when the manure is dry and crusty it's hard to work with. It takes a lot of energy to chop it into small pieces that are suitable to work into your gardens. I would suggest you pile it up outdoors and wet it and also leave it out in the rain. Work it from time to time to break it up. You could also work it into a compost pile. Making layers with your fall leaves would make wonderful compost and eliminate the scares your getting above.

As far as nutrient values manure is as high as any bagged fertilizer you can buy. Bagged fertilizer is rated by weight and so is manure. Unless you would scatter a cup full of manure over a garden plot you will not need any additional fertilizer. You can apply a few inches to raw clay and grow wonderful crops, without any burning problems. To black loamy soil an inch will work wonders and you will again not need any additional fertilizer. Maybe lime in both cases; if warranted.

If that were my manure, and my garlic, I'd be planting my garlic and covering the bed with that bedding as a thick mulch to be pulled back in the spring. And prior to planting, I'd be applying bone meal from a reputable source three inches under the cloves.

I now have a good supply of year old horse manure.

We are going to use a test plot to make sure there is no chemical, that will harm plants.

Old, uncomposted manure may have safe amounts of nitrogen, but may still contain bacterial loads that hot composting would kill.

Goodness jolj, what chemicals do you think people feed horses that will harm plants? Or what do you think the folks are dousing the manure with before you get it?

Of course, if the horses were eating feed contaminated with clopyralid or picloram, you wouldn't be doing your plants a favor putting their manure out. Herbicide carryover is actually a very common problem these days. Breakdown in manure may take years, especially in the absence of sunlight. You might ask the previous owners about whether their feed came from treated pasture. Be careful! You spread contaminated manure on your garden, and your garden bed will be unusable for a long time.

The manure that I avoid is manure with lots of wood chips in it. That is because they use wood chips as bedding in the stalls. I've had problems starting seeds in soil that contains wood chips. In fact I have a suspicion that the stories of seeds not germinating in manure is from the wood chips and not from the contamination that is cited. If the wood chip/manure has a measurable amount of say a wormer then a test may blame it on the wormer; whether or not it's a sufficient amount to have caused the problem.

Clopyralid or picloram are easily detectable and measurable, and it's very clear how much is necessary to kill plants. No, it's not just that seeds might not germinate, it's that seedlings die. Oh, but Dow Agrosciences should be using wood chips as herbicides? Who knew?

Goodness jolj, what chemicals do you think people feed horses that will harm plants? Or what do you think the folks are dousing the manure with before you get it

It has happen to OG in the past, but found out that the horse ranch owner, said that her husband

used the same manure in his garden, so it is fast.

I have berry, fruit & nut plants, so I take no chance with manure/compost did not process myself.

It is the hippie in me" trust no one, question everything"

I am too old to start a garden in old depleted soil, so I will guard the garden of fifteen of soil building.

The manure has red worms in it also, so no wormer, and proof that it is not compost as of yet.

Redworms do not live in compost soil, that would be night crawlers, not redworms.

I thought conventional wisdom was that picloram and clopyralid degraded in about 2 years.

Another thing to keep in mind about barn cleanings is that some barn owners use slaked lime to control odors, and the manure can end up with a very high pH. That would certainly screw up both seeds and live plants. Always good to ask the donor if they use lime in the barn, and if so, what kind.

I never realized the red wiggler/nightcrawler indicator.

The site I get my manure from has two piles. One hasn't been added to for about 4 years. I seem to remember seeing night crawlers in that manure. The other pile is being added to regularly; as you might expect. The last time I went there I went for fresh manure for my hot frame; so I took what I needed off the top of the pile that's being worked, the fresh stuff. There were red wigglers in it. So you will find one or the other in fresh or the old pile which is somewhere between 4 and 15 years old as I'm taking it off the bottom of the pile which half way up the hill side the manure was dumped on.

Which means if you don't see one or the other you might think twice.

When I go for manure I rent a pickup truck and load it at the barn, then bring it home and shovel it out onto a pile. I don't use it all at once so it's been turned twice and is composting till I make the pile small enough that it stops. This year I ordered mushroom manure on March 17, It's now June 13 and about half of it is still there on the compost pile. They compost human manure for 13 days and called it "Well Composted". But I still try to dig in my manure at least the fall prior to spring planting. I used leaf compost to amend this years lettuce, scallions, radishes, and potatoes. It's just more appetizing.

"I thought conventional wisdom was that picloram and clopyralid degraded in about 2 years."

As I said, that's a long time not to be able to use your garden. Actually, it depends on sunlight exposure. More sunlight, faster degradation.

Yes, bottom line is to find out from the horse owner what the deal is. "Trust no one, question everything" works for me.

John, redworms eat decaying matter. They're not indicative of any stage in the compost process. I won't speak for nightcrawlers.

Ann - I was trying to make the point that in any part of the composting there are worms in it. i was surprised to see them in the fresh manure as I would assume that it might be too warm.

As kids on the farm,beneath horse and cow piles a few days old were the best place to find fish bait worms in Summer. What I'd suggest to those unsure of manure is toss seeds on a large sample and keep it damp to see if seed germinate. If you don't already have composting worms,get some to hearvest best potting soil available. When you bring new manure home,wet some and put worms in it to see how they prosper. IMO,manure is better aged than fresh. Kept damp and turned,thousands of seed sprout then are killed when pile is turned. Others deep in pile are killed by heat.

Red Wigglers | Tigers of The Soil

Red wiggler (Eisenia fetida) are otherwise known as red worms or tiger worms. They are similar to earthworms (even categorized as a species of earthworms) with only a few differences in their features.

Compared to regular earthworms, red wiggler are usually tinier and shorter. They also have a reddish-purple hue that distinctly distinguishes them from earthworms.

Below are some of the basic facts that differentiate red worms from common earthworms:

• Red wiggler mainly feed on manure and rotting plant matter.
• They can withstand high temperatures, unlike earthworms.
• They do not burrow deep into the soil as earthworms do.
• You’ll find them closer to the earth’s surface in large groups.
• They reproduce quickly.

Yes, John, I was quibbling with Joli saying that you would not find redworms in compost. Redworms are in my compost in all of its stages---even when finished.