What is it exactly about dog urine in regard to lawns?

[bajafx4]

My dog has a few spots on the lawn where she unitates daily... usually several times daily; those spots are currnetly brown and show no sign of living grass. Fortuneately, those spots are on the side of the house where I'm not too concerned about my lawn quality. However, there are a few spots throughout my lawn where she only urinated once during the past few weeks (since the snow has melted) and those spots are now very green and actively growing compared to the rest of my lawn. I assume the amount of urine will come in to play, so I'll mention that she's a big 90 lb. dog.

FWIW, last year I shamefully used the Scotts "Step" program, but this year I'm doing things a bit different and just put down my first application of Milorganite yesterday at the recommended 15 lbs. per 1000 sq.ft.

[simpson]

Urine is like spraying nitrogen on the lawn. The reason the spots are very green and growing is because the urine is like putting down nitrogen in that spot. It has or may not burn like the side of the house because its still cooler out and more rain in spring. The spots on the side of the house are dead because the nitrogen has burned the lawn and killed it. One thing you could do is flood the area with water after your dog is done. Another is to at first sign of yellowing put sugar on the spot. The sugar feeds the microbs and they take up the nitrogen ( I guess thats how it works) and it keeps from killing the grass in that spot. It may be weak but not dead.

It also has to do more that she is female because most unload in one spot unlike a male that marks his spots.

[GaryCinChicago]

Urine equals nitrogen.
Take some 46-0-0 urea and dump a half pound in a 12" circle. In short time, it will look like a urine spot.
Urine smells like ammonia. Synthetic nitrogen is made form ammonia.
1 gallon of ammonia dumped on a 12" circle on the lawn will look like a urine spot.

Female dogs can be trained to "go" in a potty area. My female dog is larger than yours and goes in a 10 X 14 pen with pea gravel.

[MorpheusPA]

Agreed. However, we have three dogs and no dog spots in the lawn or gardens at all.

The key to binding up nitrogen...is simple carbon. Any source will do, but sugar tends to work the fastest. Sprinkle a good handful over the spots where she goes weekly and you'll notice, over time, the spots get smaller. Using organics will also help--as the carbon reserves in the soil rise, burning becomes much less likely. It's difficult to put too much sugar down, so don't worry overmuch about that.

For bacteria, the optimal carbon to nitrogen (C:N) ratio is around 9:1, depending on the species. So bacteria are going to reproduce and be very happy in a soil that has nine times more carbon than nitrogen. If you compost, you may have heard of the magic 30:1 ratio, where you try to get thirty times more carbon than nitrogen. That allows sufficient nitrogen for the bacteria but not so much that the fungi give up the ghost and die on you. Personally, I compost anywhere from 20:1 to 40:1 and have good luck all across the range.

Ultimately, in the soil that would be your goal, but any adjustment will help.

[tiemco]

Hmmm, I have to disagree with you Morpheus unless I am reading your statements incorrectly. When you say "simple carbon", I think of graphite or diamonds, and neither of these will bind nitrogen. Sugar is not simple carbon, but sugar itself doesn't readily bind nitrogen. The OP says the area that receives heavy urination is brown, while areas that get occassional urine are nice and green, which makes perfect sense. The burn is caused the huge nitrogen build up in the soil (too much for the soil bacteria) that consequently dessicates the grass because the soil concentration is so high. The occassional urine areas (which are nice and green) is akin to sprinkling a little fertilizer, which isn't enough to cause burn to the grass since the amounts aren't high enough to do damage. The sugar is the fuel for the bacteria and fungi which in turn act on the nitrogen (in the form of mostly urea/ammonia). On the other side if your soil carbon/nitrogen ratio is too high then you can have the situation where the soil bacteria is using too much nitrogen, thus depriving it from your grass.

[MorpheusPA]

I probably should've said "simply carbon," although you could throw some ash down if you like, I suppose, although I wouldn't because it's alkaline just like most dog urine (except Dalmations). Plus the simplest safe carbon source, organically, is glucose (although table sugar is sucrose).

The sugar increases the number of bacteria in the soil by a vast amount, and those can then process the nitrogen (usually into biomass). Yes, that will deny the nitrogen to the grass--since it's burning because of the N levels, that's what you want to do in those particular spots. Except for the slowness of action, I wouldn't have too much issue with digging in fresh sawdust in those areas--with a C:N ratio of around 300:1, it can suck up a lot of nitrogen before allowing a burn. You just don't add so much that the entire area goes into extreme nitrogen-debt.

Balance is always the key. A 90 pound female dog can add a LOT of nitrogen to one spot (and females tend to pee in one spot when they go). If you balance the C:N ratio to 30 and keep it there, that's nearly perfect. There will be enough carbon to absorb extra nitrogen, but not so much that it causes a shortage. I wouldn't have an issue with 50:1 to give a little margin as she goes, and that's not so high that the available N levels will fall too far. I've composted at that level and it works fine, just a little on the slow side.

This isn't an exact process. Last year, I added 34 pounds of organic nitrogen...and an estimate of well over 3,000 pounds of carbon, most of it topdressed leaves, and that carbon estimate is probably on the low side. The lawn is still radiantly green and growing extremely fast for March. I got a great population of fungi, plus nitrogen-fixing bacteria in the top layer, taking care of the issue for me.

[tiemco]

I guess I just have a problem with your phrasing such as "it can suck up a lot of nitrogen before allowing a burn" and " There will be enough carbon to absorb extra nitrogen". You make it sound like the carbon is binding up the nitrogen compounds in the soil thus preventing burn when in fact that isn't happening. The sugar will increase microbe activity but will it be high enough to remove enough nitrogen from the "pee zone" thus preventing burn? I would say probably not, and the best solution would be watering in the pee zone often to reduce the high nitrogen concentrations as well as leaching it below the roots, thus preventing the burn.

[MorpheusPA]

I'm oversimplifying; I'm often too pedantic.

The answer, actually is yes...it is high enough. Even just changing to heavy organic feeding supplies sufficient carbon for energy so that the bacteria have no trouble processing the excess nitrogen. We've three dogs, no burns. My mother has two dogs, massive burns...until we changed over to organics. Those are now shrinking away.

[turf_toes]

My own observation is that the sugar trick works. I had a couple of spots in my lawn where neighbor's dogs would urinate every day. I'd transplant grass from garden edging to the spot, but before long, the dogs were hitting it again and it was burning (again).

I tried the sugar application (I think it was a tablespoon of sugar in a gallon of water) and it worked like a charm. No more burn spots. It didn't magically cure the existing burn. But it appears that the grass was able to recover and fill in. Best of all, the dogs stopped urinating in those spots.

I don't know the science behind it. But I do know it's worked for me. Just my two cents.

[Dchall_San_Antonio]

In chemical gardening they talk about carbon freely. They do not mean black carbon but they are really (REALLY) not sure what they mean. Still the discussion continues regardless.
Carbon => carbohydrates. When soil scientists talk about carbon, I assume they know they mean carbohydrates, but I can never be sure.

Nitrogen => protein. I am convinced that only a small minority of soil scientists know that and virtually nobody outside soil science is aware - unless they read my comments. Urine is not a protein but is high in fast acting (hot) ammoniacal nitrogen.

Soil microbes eat (decompose) protein, carbohydrates, vitamins, enzymes, and minerals. If they and the plants get too much urine, they can all die away leaving dead grass and soil with not enough living microbes to process all the urine. The microbes can be brought back with carbohydrates. The carbs stimulate them to reproduce and within a week or so the grass should start to return. Interestingly the new grass is often much deeper green than the surrounding grass.

[MorpheusPA]

Well, a lot of the carbon in my soil at this point is lignin, chitin, and a few floating carbohydrates. But it's all good and the fungi like the first two at least.

[kevreh]

Urine equals nitrogen.
Take some 46-0-0 urea and dump a half pound in a 12" circle. In short time, it will look like a urine spot.
Urine smells like ammonia. Synthetic nitrogen is made form ammonia.
1 gallon of ammonia dumped on a 12" circle on the lawn will look like a urine spot.

Female dogs can be trained to "go" in a potty area. My female dog is larger than yours and goes in a 10 X 14 pen with pea gravel.

Gary-


I have a 3 year old female dog that really burned and killed a 5x5' patch of lawn that I cringe at every time I see it. Any tips on getting dogs to pee somewhere else? Since you have a pen you can control where she goes, that will be tougher with my (open) backyard.

[bernstem]

You can train your dog to use a spot in the yard. Some owners will make a small mulched area for them. At that point, it is training. Training is an art and you need to have a feel for your dog and for how they react to you. Timing and consistency are critical for good results and everyone in the family who cares for the dog needs to be on board for it to work well. As a general overview:

If they are already trained to pee on command, put them in the designated area when they first go outside and ask them to pee. Many people use the phrase "hurry up". When they do their business, praise them profusely. You also need to watch them like a hawk when they are outside. At the first sign that they are going to pee, you need to scoop them up, possibly verbally reprimand them and deposit them in the designated area and use your command phrase. Then praise them profusely for peeing in the right spot. For most dogs, you don't need to directly punish them when they pee in the wrong area. The act of scooping them up or dragging them away in the middle of their business is usually enough.