Ash in the garden

I made some (mostly) wood ash yesterday. Went around and picked up twigs from our thorny hardwood trees, broke them up and shoved them in a tomato paste can from the cafeteria. Poked vent holes in the bottom, put a couple pieces of cardboard and dried sugar-cane scraps in the middle and lit them on fire. It burned and then smoldered for several hours and left me this morning with a nice little bit of ash.

I wanted to use ash as an additive to my gardens, but I'm curious how others use it. I've read studies where urine (my primary fertilizer) mixed with ash has better results. But I didn't see how the combination was made.

I plan to sprinkle a bit around some of my flowering trees and plants, and put some in my "super-sawdust" (https://permies.com/t/121746/charging-sawdust). But past that, I'm curious how else I can use this source of fertility.

Also, and very important, how much is too much?

Priscilla Stilwell wrote:I made some (mostly) wood ash yesterday. Went around and picked up twigs from our thorny hardwood trees, broke them up and shoved them in a tomato paste can from the cafeteria. Poked vent holes in the bottom, put a couple pieces of cardboard and dried sugar-cane scraps in the middle and lit them on fire. It burned and then smoldered for several hours and left me this morning with a nice little bit of ash.

I wanted to use ash as an additive to my gardens, but I'm curious how others use it. I've read studies where urine (my primary fertilizer) mixed with ash has better results. But I didn't see how the combination was made.

I plan to sprinkle a bit around some of my flowering trees and plants, and put some in my "super-sawdust" (https://permies.com/t/121746/charging-sawdust). But past that, I'm curious how else I can use this source of fertility.

Also, and very important, how much is too much?

The Urine and Ashes boiled together make Potassium Nitrate crystals. Ashes have a crazy amount of Potassium. Urine has Ammonia (a liquid solution of Nitrates and Water) and that is best converted by bacteria. You can mix it with water from a pond that has algae or fish in it and Use the water as both a source of bacteria and to dilute the urine enough for those bacteria to work. If you give them a substrate with carbon and plenty of oxygen, you will get your fertilizer. Some people compost their urine mixed with straw or sawdust and turn it often. Others put the urine-water mix into buckets with air stones like you use in aquariums. Either way, if you do that, and take the liquid and boil it, then add lye, crystals will suddenly fall out of solution. Those crystals are fertilizer. But they are crazy strong. I hope that made sense. If you decide not to use it for fertilizer, you can always use it to remove tree stumps by adding finely ground charcoal and sulfur. There is a lot of info on it out there, I recommend the youtube channel Cody's Lab to learn more...

Priscilla Stilwell wrote:I made some (mostly) wood ash yesterday. Went around and picked up twigs from our thorny hardwood trees, broke them up and shoved them in a tomato paste can from the cafeteria. Poked vent holes in the bottom, put a couple pieces of cardboard and dried sugar-cane scraps in the middle and lit them on fire. It burned and then smoldered for several hours and left me this morning with a nice little bit of ash.

I wanted to use ash as an additive to my gardens, but I'm curious how others use it. I've read studies where urine (my primary fertilizer) mixed with ash has better results. But I didn't see how the combination was made.

I plan to sprinkle a bit around some of my flowering trees and plants, and put some in my "super-sawdust" (https://permies.com/t/121746/charging-sawdust). But past that, I'm curious how else I can use this source of fertility.

Also, and very important, how much is too much?

Priscilla, do you remember where you read about urine and wood ash mixed together?  I'm also trying to learn about the possibilities of these two sources of fertility that we have in abundance.  I've heard a bit about mixing the two, but haven't been able to find much in writing.

My latest project is experimenting with ways to preserve at least some of the fertility of urine that is produced during the winter months when (here in the temperate zone where I live), our plants are not actively growing. Right now I have a long trench filled with wood chips that I empty urine into. But maybe mixing it with wood ash could be another way to go.

Ash has two potential uses in the garden.

1) The first is that it acts as a sort of lime, and increases the PH in the soil. We use wood ash here as a lime substitute on a large farming basis for that reason.

2) The second use is as a weak fertilizer, keeping in mind it is a VERY weak fertilizer. On the NPK scale it has an equivalent of 1/2/3. Of the 3 major nutrients, a gardener or farmer is most likely low on the first one, nitrogen, and that is where urine is the highest. So by using urine with wood ash, you get a higher amount of nitrogen, with some higher amounts of potash, that increases the PH in the soil.

It is a win/win/win

Travis Johnson wrote:Ash has two potential uses in the garden.

1) The first is that it acts as a sort of lime, and increases the PH in the soil. We use wood ash here as a lime substitute on a large farming basis for that reason.

2) The second use is as a weak fertilizer, keeping in mind it is a VERY weak fertilizer. On the NPK scale it has an equivalent of 1/2/3. Of the 3 major nutrients, a gardener or farmer is most likely low on the first one, nitrogen, and that is where urine is the highest. So by using urine with wood ash, you get a higher amount of nitrogen, with some higher amounts of potash, that increases the PH in the soil.

It is a win/win/win

When you say "using urine with wood ash" are you referring to mixing them together before use?  If so, any thoughts, experience, or resources about technique?  This is what I'm most interested in--methods of combining the two. But there's more than one way to go about it obviously, and questions come to mind. For instance, if you mix urine with wood ash the now you have clumpy wood ash, not the best for spreading evenly. Does it make sense then to dry it out first before application? This is what I'm pondering.

If you just mean using urine and also using wood ash, but not mixing them, then the methods are pretty clear. I'm more interested in the former though.


Dave

I think Dr. Redhawk discusses that somewhere in his soil series.

I think it would be best to use them separately, because, as mentioned above, mixed together they would be a clumpy mess, whereas separately they are easy to distribute.

Neither urine nor ash have much organic matter to improve you soil, so they kind of work like (weak) chemical fertilisers and don't improve the soil long term. When I have used urine (heavily diluted) directly on the soil below plants, I find it tends to lead to aphid population explosions, so I think it gives too much nitrogen, too fast. It might be worse because my soil doesn't have organic matter yet, so after it does, perhaps the soil will be able to buffer and utilise the urine better.

If you have any carbonaceous material to compost the urine with before using it in the soil, that might make a better soil amendment, in my opinion. Instead of using diluted urine directly, I use wood shavings and sawdust as cover material in the compost toilet, hoping that after a year or two, it will have all decomposed together into a nice compost. There are very few biomass waste products available in my area, and farmers who own trees burn even finger-thick twigs in the cookstove. One of the only sources of free biomass I can find is sawdust and shavings from the lumber yards and furniture workshops. In winter it is not a waste product, as people buy it for fuel, but in summer it is a bulky and hazardous waste product for those workshops, so we can take it for free. Also, in autumn, many local farmers burn their fallen leaves, so I gave sacks to one family and got 6 huge sacks of leaves.

Ashes can be harmful for the land if you use a lot of ashes on a small area, because they are alkaline. But a light sprinkling of ashes mixed into the soil every year can bring a great amount of potassium, and smaller but helpful  amount of other nutrients (but not nitrogen). I think it's probably traditional in every part of the world.

I like to think of the "nutrient cycle" -- if we are removing food from the land, we have to replace the nutrients. If we put all the nutrients we eat back into the soil via a composting toilet, theoretically that should be exactly enough nutrients to produce the food that fed those people. Nitrogen is the only important plant nutrient that can be lost to the air, but can also be gained from the air with nitrogen fixing plants. Using urine soon rather than composting it can preserve more of that nitrogen. All the other important plant nutrients don't tend to gas off, so they stay in the toilet manure and go back to the land in a beautiful cycle. Ashes from fuel that was gathered off site is a natural and traditional way to gather nutrients from offsite to the farm or garden.

Dave Meesters wrote:When you say "using urine with wood ash" are you referring to mixing them together before use?  If so, any thoughts, experience, or resources about technique?  This is what I'm most interested in--methods of combining the two. But there's more than one way to go about it obviously, and questions come to mind. For instance, if you mix urine with wood ash the now you have clumpy wood ash, not the best for spreading evenly. Does it make sense then to dry it out first before application? This is what I'm pondering.

If you just mean using urine and also using wood ash, but not mixing them, then the methods are pretty clear. I'm more interested in the former though.

I have a fairly big farm so the scale you are referring too, and what I am referring to is kind of different.

I used to use tons of wood ash here because it was free, but in some ways that is the problem. It used to be ash from the wood boilers and paper mills was free, and so I would use that as a lime product, but then the government realized us farmers wanted to take wood ash, but not sludge, which is the 1% of municipal waste human manure that the wastewater treatment facilities cannot treat. So they deduced if we wanted ash, but not sludge, to get rid of the latter, they would mix ash in with sludge and thus we would take it.

I will not.

Most of the other farmers in the area will, but this farm has always been against sludge, and as long as I own it, that will be the case.

I have no issue with my own human manure, and when I pump my septic tank, I will spread it on my own land...my furthest field away which is about 1 mile from the closest house...but no way do I want everyone else's human waste spread here. (Condoms, drugs, medications, etc spread on my farm land).

For a lime product, I use an ash-lime which is used as a scrubber for the paper mills. It has some ash in it, but is mostly pure lime. I have to pay $22 per ton for it, but it is more potent then quarried lime so I can use less tons of it to the acre.

Another product I use is seaweed which has a cost of $1 per ton, BUT it takes 10 tons of it to equate to 1 ton of quarried lime.

For "urine"...nitrogen...I use liquid dairy cow manure, or sheep manure.

For my own garden, I just dip into my piles destined for my fields, and spread that on my garden.

One thing to remember about using ash, especially when using tons (relative) is that you can use it BUT it also has high salts. This if used year after year can cause plants to "THINK" there is a drought, even IF you water them well. This is why if you use it as an addition regularly or tons as a lime, I was told to change the side-dressing or use different things than ash for changing pH. I was told that some side-dressing is fine and using potash instead of lime is to be only once every 3+ years to keep salts from building up in soil. Instead of ash you might want to look into making biochar instead, anything that can be turned into ash can also be made into biochar.