sodium leaches very quickly from the soil, compared to nitrogen, soon your compost will not be salty. Also, someone who has urine like sea water is really eating a lot of salt and drinking little. For growing season applications, it is best used with established plants, also beta and brassica spp. deal with the salt better than other vegetables.

You have good questions. I think it is better to use a "pee bale" of hay to capture that N rather than salting up your compost. When the hay is used as mulch, excess salts wash away. As a liquid feed urine works like a charm diluted 20/1. You'll get "dog spots" if it's not diluted.

Well, I guess my point is that since salt leaches from soil quickly, what's the problem with peeing straight on your plants? By the time it gets to the root zone, the salt will be headed south.

But the point about dog spots is a good one. That's probably not about salt, and more about nitrogen burn. So the reason for not peeing directly on plants is probably less about salt and more about nitrogen burn from what is essentially concentrated fertilizer.

Now, to the extent that salt or fertilizer burn is an issue, I guess it would mean that it would be best to stop adding urine to compost well before it gets used. The excess nitrogen should get burned up by the decomposition, and the salt should be allowed to wash away, before the stuff gets put on your plants.

But this all is only true for pit composting. If you do composting in a barrel, that salt isn't going anywhere. In fact, it's just going to build up as the moisture evaporates.

My understanding is that the N in urine is largely lost to off-gassing if it is poured into the pile or just on the ground. Poured dilute around growing plants into highly live soil will still involve losses to off-gassing but some will be rapidly consumed by soil bacteria. Perhaps poured into a quite active hot pile will have less loss, since there are hugely more active bacteria to work fast.

My piles are generally "cold" so I stockpile as much urine as I have airtight containers. So you answered your own question in the OP with "save it!"â¦

Well, nitrogen in urine is in the form of urea, which is CO(NH2)2. That doesn't "off-gas", I think. It's not a gas. In fact, in dry form urea is crystalline, which happens to be highly soluble in water, which is what's going on in urine. Nitrogen as a gas is totally different, and it is not usable by plants directly. The soil bacteria convert the urea into ammonia compounds, nitrites and nitrates, which are forms of nitrogen that plants can use. Some of that ammonia can off-gas, I suppose, but a lot of it stays dissolved in the soil moisture. That's a good reason not to let your compost pile dry out.

So you're not going to lose much nitrogen from urea in proper composting. Now, it is true that since urea and all the nitrogen compounds produced from it are highly water soluble, you can lose nitrogen by leaching. Don't over-water your compost.

That is, if you poured urine into a cup and left it there for a few weeks, the nitrogen would still be there. No off-gassing going on.

the dog pees in the general vicinity around the apple tree and the lemon tree, the crab grass is dead but the apple tree and the lemon trees are thriving. she doesn't pee on the tree trunk but about two feet away. seems like those trees are benefiting from the pee.

Here is my 2c. I rent a large field and although there is a bathroom in the barn, I usually pee in a bucket of water. This is a great N source but also repels animal pests. I would possibly do the pee bale if I was a guy. But I wanted to mention the use as an animal deterrent.

Yes, I had wondered about its effectiveness as a animal deterrent. Especially for squirrels. Now, I have heard that there is a repellant being marketed that contains coyote urine, and, FWIW, the reviews haven't been all that impressed with it. Now, it could be that urban squirrels don't consider coyotes to be feared predators, but ...

Anyone tried using human pee to repel wild animal garden pests?

What an interesting question. Especially about the build up of salt. Perhaps rain, when it finally comes, washes a lot of it away.

I do not believe it to be a good idea to wee in the compost, not because the neighbours might be peeking through the fence but because the composting process might not like it.

In composting toilets, wee/pee is shuttled off elsewhere, my husband reminded me one day when I suggested an alternative place for the contents of his bladder.

So I think it is much better greatly diluted and applied to plants.

BTW, I once heard that very strong, old and stale and totally revolting wee wees kills couch grass.

It doesn't.

It nearly kills humans though.

Dan, I have tried it and it does not work.

sodium in urine is like a substitute of potassium that looks a lot like potassium but does none of the potassium's jobs in a plant, which is bad cause plants take up sodium more readily than they take up potassium, which could eventually lead to potassium deficiency.

The Na problem is a bit overblown. Here in Michigan, with all the winter road salting, you would expect to have desertified road sides. But that is not the case. And we are probably talking about one or two orders of magnitude more deposited Na.

This post was edited by glib on Mon, Jan 5, 15 at 9:30

I have also tried fresh pee around my tomatoes and the deer could have cared less.

That's an interesting point, glib, about the lack of desertified roadsides in areas that do heavy salting of roads. Now, that's not to say that your roadsides might not be a lot more herbaceous if the roads hadn't been salted. There are many vegetables that are resistant to salinity (asparagus and squash, for example), and others that really don't like salt much at all (onions and carrots, for example). It is well understood, I believe, that grasses (forage crops) are more tolerant of salinity than vegetables. So peeing on your grass is probably a lot less harmful than peeing on your veggies, and you probably won't see too many carrots and onions on the Michigan roadside.

But I'm beginning to understand that nitrogen burn, rather than salt, is the main reason to dilute urine before crop application, and that's the reason why full strength urine on compost should work fine. Burn away! Again, though, I'd be careful about composters that are not well drained, as in barrel tumblers. Salt will build up in those and you could end up with pretty salty compost.

No big surprise that human urine isn't much of a pest repellant. At least for urban squirrels, which are my biggest pest, NOTHING smelly seems to repel them.

If you haven't read it yet, there is a good discussion at the link.

tj

Here is a link that might be useful: Minding Ps & Qs

Don't buy predator urines as animal repellents. They are harvested from animals kept in very bad conditions. So bad the animals wish they could just be fur coats already. Lots of deterrents are animal urine based and I will not use them, or wear fur.

Thank for the link to the earlier discussion. I was aware of that, but hadn't looked at it in a while. That discussion talks a lot about salt, and it also talks a lot about compost, but not about the effect of contributed salt to compost, which is what my original question was about. It is impressive that pee has a discussion lifetime of almost ten years!

I think I've concluded that IF you're going to pile a lot of compost on your plants, it's probably best not to apply full strength urine to it when it is maturing, but in the early stages of composting it should be fine to do that. I also have to be a little suspicious of urine-stoked compost that hasn't had any opportunity for leaching.

Good point about sources of predator urine.

I do think nitrogen burn is the biggest concern and that is why most people suggest going around the plant and not on it. During the growing season, I keep a milk jug for DH to supply fertilizer into first thing in the morning which is easy for me to dilute in the jug and spread the application to multiple areas. I think it is like most anything, too much of any one thing is bad, so diversify. I generally keep it out of the vegetable garden though as I give some veggies away and not everyone is as enlightened about such things.

I have tried establishing a perimeter with the smelly stuff, the squirrels, rabbits and deer were not phased. Wished it worked better as I wish that Irish Spring, human hair, etc, etc all worked better.

It occurs to me that the best thing to do with urine in the winter (especially if you maybe have too much for your small compost pile), is just to fling it on your garden beds. If you dig in, as I do, lots of organic matter in the late fall (ground up leaves, etc.), a moist top-dressing high in nitrogen is just the ticket.

Very good, Dan. For small gardens that is the ticket. Composting as a separate activity is wasteful of your sweat equity and of the nitrogen in the OM. But if you dig it in, all nitrogen in the OM is used, and extra nitrogen can be stored. Not to mention you will have far more earthworms and fungi.

I think in the winter it could also be good on areas with wood chips, especially if the wood chips are to develop future areas. Where I am at, winter would actually be one the better times for applying it as the (hopeful) snows could help dilute it. Perhaps I need to start asking DH to get on it.

Well, I think the point of peeing in your bed (no, I didn't mean it that way!) in the winter is that if nothing is growing in your garden, you don't need or want to dilute it. You can't get nitrogen burn on plants that aren't there. In fact, the effect of peeing directly in your bare garden bed is the same as throwing a heap of lawn fertilizer on your bare garden bed. It'll just break down the organic matter faster. (In fact, that's one way to get hot compost in a small pile. Just seed it with a lot of high N fertilizer.)

But certainly wood chips are a good target for it, because wood chips are otherwise going to take a lot of time to break down. Peeing on wood chips almost certainly accelerates that breakdown.

Now, my compost pile is in a pretty well hidden place, but my garden bed is not. So either I'll apply it at night, or keep a bucket handy and apply it less conspicuously.

P.S. Might be smart to stop doing it a few weeks before actually putting plants out in that garden bed. Also, might be smart to make sure that garden bed is well leached with rain or snow by then to cut down the salt.

As I was saying earlier, now you got it completely. Leaves, too, will store N.

Leaves won't store much nitrogen. Dry leaves are mostly carbon. C/N ~ 80, I think. So in composting leaves, you need an added source of nitrogen if you want them to get digested readily.

little minnie, we visited the whole predator urine issue in another thread recently, and used some humor to help lighten the sadness about what the animals go through.

I'll link it below in case you want to take a look.

daninthedirt, the thread also has some interesting info on storing vs using winter urine, before we got completely ot and started writing original screen plays.

Here is a link that might be useful: Winter Urine

leaves will store N when irrigated with a N rich solution.

Thanks, Elisa. That's a pertinent thread. I had never considered application of urine to a garden bed in the winter to be a good way of nitrogenating the soil in a way that would be helpful in the spring. The nitrogen fixed in that way will probably be long gone by springtime. But application of urine in the winter to decompose carbon-rich materials you've dug in is how it should be useful. So that's a good point that if you're not doing any over-the-winter in situ composting in your garden bed, you might as well save the urine until summer. Sprinkling a garden bed in the winter, when nothing is going on there, is just a waste of time.

To glib, leaves won't "store" nitrogen, I think. But the composting process will convert that urea nitrogen into nitrites and nitrates which, as noted in the soil thread, are water soluble, and will leach. I may be wrong, though. What's the process by which dried leaves store nitrogen? You mean they just soak up the urine and hold onto it like a sponge?

yes. The urea binds to the lignin or cellulose, same as with wood chips, though I do not know the exact chemical process.

OK, I can see that as a short term process, but once it binds, doesn't it start composting? It doesn't just sit there bound up, does it? Of course, lignin at least doesn't break down that easily, so maybe the urea does just grab on to the lignin and hang in there. If that's the case, then urea is a better long-term release fertilizer than nitrates. That's kinda cool. It would still mean that if you want to pee on your garden bed in the winter, that garden bed ought to have some uncomposted high-carbon material dug into it. It may also mean that plants in a garden bed that has uncomposted organic material in it may be more resistant to nitrogen burn from applied urine.

I need to do some reading about this.

Once it is there, certain bacteria can incorporate it into the leaf tissue. Composting brown materials is just a matter of incorporating enough nitrogen in the material. So urea+leaves yields composted leaves rich in nitrogen. Looks like you got it right.

That's really important for me to know because every year I accumulate about six to eight trash cans full of ground up fall leaves. Those ground up leaves get dug into my beds in November and December. Sometimes I throw some lawn fertilizer on top. But what I'm beginning to understand is that I also should throw some full strength urine on top in the winter. The more the better. As in, NOW. I gotta go get a drink ...

Now, when things are growing in these beds, and I still want to use urine as a fertilizer, I have to highly dilute that urine before I do. So I guess I wouldn't use anywhere near as much in the spring and summer as I would in the winter, when I can go full-strength.

Now, I understand that humans urinate more in the winter than in the summer. Why? Because in the summer, we lose lots of fluid by sweating. So, somewhat amusingly, we pee more in the season when at least my garden beds can use more. That fits. If I wanted to save urine, I wouldn't be saving it for the summer. I'd be saving it for the winter.

Link to a direct donation demo in the Las Vegas desert.

https://www.youtube.com/watch?v=gZhHD1w9P8E

So, um, that's a lesson on how to do it? Gee, I never would have guessed. But the purpose of this thread was really the biology and organic chemistry of applying urine in compost and garden beds. We could start another thread on the plumbing and targeting required to do that application maybe? You know, how to point and shoot.

FWIW, urea, the nitrogen containing component of urine, is colorless. So the color of your urine isn't necessarily an indicator of how likely it is that you're going to burn your plants with it.

glib and dan, thanks for discussing this and then narrowing it down to "do this in summer, this in winter" simplicity!

Somebody should write an article, no?

Yes, Elisa, there is a lot of pee-is-good and pee-is-bad, but not a lot of easily available wisdom about when and how. I mean, chemical fertilizer is good and bad, depending when and how you use it. I'm just beginning to get a clue. What I'm concluding is that for composting (whether in a separate pit or in-situ in an unplanted bed), it's good. Really good. As long as there is natural leaching to prevent salt buildup. That points to winter. As a fertilizer for active crops, some care is needed, as in a lot of dilution, but might be useful. That's for summer. But it's looking like you can use a lot more of it in the winter than you should in the summer. Let's all drink heartily in the winter.

I'd really like some soil biochemistry experts to weigh in here, though. We're talkin' biochemistry.