I'm always interested in John's input on matters relating to soil. Let's use this thread to ask him clear questions. Let's ask for clarification but refrain from rebuttal. --------

Let's wait to hear from John. I'll PM him to make sure that this won't burden him with too much work.

I figure there are others interested in John's opinions. This could save him from a mountain of PM questions.

No problem at all Dale. I'm happy to be the chemistry answer man here. Soil chemistry, fungi chemistry, recycling chemistry, hit me up with what's puzzling you.

I have just found a large batch of dumped woodchip.

why is white fungus in it? not a lot but enough for me to ask. is it safe to start mycore? or should i just use it for my path?

thanks

fiona smith wrote:I have just found a large batch of dumped woodchip.

why is white fungus in it? not a lot but enough for me to ask. is it safe to start mycore? or should i just use it for my path?

thanks

That white fungus is mushroom mycelium breaking down the cellulose and lignin. The spores are blown in on the air and all it takes is rain and warm weather for the fungi to take off. Don't waste it on a footpath, it's prime material to be mulching your summer vegetables with.

There may be times when I want get rid of something awful such as dead animals or noxious weeds. I have some pretty big hugelkultur mounds with flat tops. My plan is to heap said material into a crater carved into the mound where a hot compost would achieve total kill of pathogens and rhyzomes etc.

I think this is a good spot for this since the insulative nature of wood waste would retain heat and speed the process along. Nutrient losses to leaching would be virtually eliminated and even nitrates in gaseous form would be absorbed by the nutrient poor bed.

John, do you see any problem in mixing hot composting with the normally slow processes in hugelkultur? Bed longevity is not a factor for me.
Thank you. Dale

Not really, Dale. The hot composting is only going to go on as long as the bacteria have something to eat and metabolize. When they run out of stuff to eat, the temperature will come down and the fungi can re-colonize it and find whatever nutrients that are left.

I think what you will notice is that there is a quick volume reduction with your hot composting, and this will leave a depression in the flat top of your mound. If you then go and fill that in with wood chips, that area will then transition over from bacterial to fungal decomposition.

Interesting thing to think about, I need to read up more on the species of fungi that are found in the end stages of the decomposition process.

i'm trying my hand at hot composting. how often should i turn it ? it keeps cooling down, but hot in the middle.
thanks

fiona smith wrote:i'm trying my hand at hot composting. how often should i turn it ? it keeps cooling down, but hot in the middle.
thanks

If you're lazy, you don't need to turn it at all. The big advantages of hot composting is that it takes less time, and the heat kills weed seeds. But to get that heat, you either need (1) a big pile that doesn't have a lot of surface area to be losing heat or (2) a black plastic container that heats up in the sun. If your compost heap is less than 3 feet by 3 feet by 3 feet, you're going to find that it keeps cooling down, but if you dig into the middle it is still hot. The larger you can make that pile, the less surface to volume ratio you have and the better it will hold in the heat. Of course the downside is that if you want to turn it, that's a lot of work. Now if your pile is 3 feet by 3 feet by 300 feet, you can just put a blade on the tractor and turn it in one pass.

I find that a black plastic trash barrel, say 30-50 gallons, makes a good hot compost unit. It holds enough of the heat in that you don't have to turn it to get the uncomposted stuff on the surface to the middle where it is warmer and the bacterial composting is going on.

If you like hot composting, that's fine, but let me point out that fungal composting has advantages too. When you leave your pile of biomass out in the rain and inoculate it with fungal spores, it will be broken down even more than by bacterial composting. The reason is that while bacteria will break down cellulose, they don't break down lignin. Lignin is the other plant biopolymer, what cross links the long strands of cellulose and give it its shear strength. When it breaks down, it makes peat, and then humus, and then smaller organic molecules that serve to chelate minerals in the soil.

How often you turn the compost pile also depends on how you intend to use the compost when it is 'finished'. If you intend to dig it into a flower bed, you probably want all the seeds killed and so turning it 3 or 4 times during the process, say once a week and letting the whole process take a month is a reasonable way to go. If that is not a consideration and you want to go to more of a continuous process, where you add new biomass at one end of the pile and take composted mulch from the other end, then that pile doesn't have to be turned much at all, maybe just a little mixing of old material with new so that the new material is adequately inoculated with the microbes doing your composting.

Great compost post. Completely unrelated - but as I seem to have your attention. John - I have posted a topic under "meaningless drivel" that I hope you will weigh in on since you seem to be quite qualified. Thanks!

I've found that a loose layer of dry leaves make a good insulation layer for small batch hot compost. Mix the materials first with adequate manure, lime, and water. The leaves are applied loosely, all around at more than 6 inches deep. They may compost a bit but that's not the goal. They are only there to insulate and block wind. Rake to the side when done.

Now a question for John. There's been talk in other threads of lack of aeration of the interior of very large hugelkultur beds. Do you see that happening and if so, would it matter that a bed transitions from aerobic to anerobic decay as depth increases ?

Dale Hodgins wrote:Now a question for John. There's been talk in other threads of lack of aeration of the interior of very large hugelkultur beds. Do you see that happening and if so, would it matter that a bed transitions from aerobic to anerobic decay as depth increases ?

You're describing my horrible summer here in Georgia. There has been so much rain that my hugelkultur beds are suffering from lack of aeration. Squash planted on top just dies. Now these were just dug down about a foot and then built up about a foot above grade, so I was hoping I would have enough drainage. Apparently not. This fall, I am going to build them up higher and plant brassicas and see how that goes. The plant that is doing the best in my garden right now is the taro. Apparently, with the daily rain and poor drainage, it thinks it's back in Hawaii and is doing just fine.

When you get lack of aeration, and the soil goes to anaerobic, plant pathogens can have a field day. That was what was behind the Irish Potato famine. It never really does dry out in Ireland, and once late blight gets a start, it's off to the races.

When I was digging these hugelkultur beds, I was pleasantly surprised to see a good amount of worm activity. I'm not sure how the worms are handling this excess of rain, but the toads are having fun while the sun doesn't shine.

John, the soil here is naturally acidic. My strategy has been to spread a generous quantity of dolomite throughout hugelkultur mounds. About 2 lb. per cubic yard. Any recommendation as to how much to use.

The material is all young hardwood.

Thanks.

Dale Hodgins wrote:John, the soil here is naturally acidic. My strategy has been to spread a generous quantity of dolomite throughout hugelkultur mounds. About 2 lb. per cubic yard. Any recommendation as to how much to use.

The material is all young hardwood.

Thanks.

That's too open-ended a question to answer. What do you want to grow on the mounds? If they are acid loving plants (blueberries) then you can use less. If you want to grow artichokes, you can use a whole lot more.

There are many plants that grow well on pure dolomitic soils, so it's very hard for you to overdo on the application. The better question to ask is "have I added enough". There are other variables that enter in and influence how much you might want to add. Was there a brush fire uphill and is the alkali produced by it leaching in your direction? Has it been unusually rainy as of late and would the added leaching mean that it's time to add some more?

If you go by the rough estimate that cubic yard of soil weighs a ton, 2 lb. is only 1/10 of 1%. That's probably enough to cure any possible Ca and Mg deficiencies, but probably doesn't change the pH all that much. Your application rate of 2lb. per cubic yard is equivalent to a field application of about a ton per acre, which is on the low side, if your goal is to up the pH appreciably.

Here's a guide on liming soils, if you want to get more exact about it, but the real test is in the results you get out of the hugelbed. If the plants respond as if the soil is acidic, let that tell you to add more dolomite.

I should have stated that I'm simply looking to get the stuff to begin to break down. I've always used a bit of lime in compost since I heard that the process slows when acid levels are too high. Since my piles contain plenty of gravel and silt, should I compost them in highly acid conditions in order to let the acid draw on basic elements within my glacial till or is it better to lime early in the process ? If adding lime at the end is suitable, I could use an appropriate quantity of lime on the finished product according to the needs of crops that I'm producing.

Dale Hodgins wrote:I should have stated that I'm simply looking to get the stuff to begin to break down. I've always used a bit of lime in compost since I heard that the process slows when acid levels are too high. Since my piles contain plenty of gravel and silt, should I compost them in highly acid conditions in order to let the acid draw on basic elements within my glacial till or is it better to lime early in the process ? If adding lime at the end is suitable, I could use an appropriate quantity of lime on the finished product according to the needs of crops that I'm producing.

That's an interesting question and worthy of an experiment -- three piles, one with no lime, one with a small amount, and one with a big amount. Try and keep everything else in the experiment the same and just observe on a weekly basis which one is breaking down better. To be a little more scientific about it, you could think of a way to trap leachate off the piles and measure the pH of it. And to be even more scientific, you need to measure the temperature inside the pile, so get 3 thermocouples, one to stick in each pile. With digital readouts and hook them up to a data logger. And then you could......*



*Note to self: Not every question has to turn into a grant proposal.

That's exactly the experiment I had in mind, minus the thermometers.

I have a couple other experiments in mind as well. All of these involve ripping hugelkulturs apart with the excavator, to have a look at the rate of decomposition at depth using various species and sizes of wood and different fertilizers. We'd also look at the various creatures, root penetration ... This seems to be something that the world wants to know, so I figure that it should fall on me to do it since I'm making several beds without perennials and the excavator makes this an easier job for me than for most.

A few other experiments are brewing.

John, I'd like to get your take on this --- Thanks ------ http://www.permies.com/t/26699/hugelkultur/Nitrogen-Fixation-Free-Living-Bacteria

Dale Hodgins wrote:John, I'd like to get your take on this --- Thanks ------ http://www.permies.com/t/26699/hugelkultur/Nitrogen-Fixation-Free-Living-Bacteria

My take? As in there's a lot more unknown in the bacterial world than there is known?

We've barely scratched the surface of the great body of knowledge about how things work and more important, how they are interconnected. When you see an environment that is supposed to be "nitrogen poor" and it doesn't really look that "nitrogen poor", that is a situation that is begging for some sort of scientific investigation and explanation.

Hi John,

We have a histosol soil on top of volcanic breccia. The soil is approximately 18", then there is a layer of the breccia gravel. This is due to our land used to be the beach 4-5 thousand years ago. The exact same gravel forms our present day beach. Our area is experiencing isostatic rebound at +- 2 mm a year. Our garden site grows grass 8' high, has wild vetch, comfrey, rhubarb, white clover. I have hand-dug "swales" and drainage ditches due to the 100+ inches of rain we receive. It is becoming more monsoonal in nature with wetter winters and drier springs and summers. We are at lat. 56. We have all the seaweed and clam shells in our "front yard that we could or want to lug up to the "back 40", along with salmon carcasses. We have planted scads of nettles, more comfrey, dandelions, clover. We are digging up the grass as it out competes almost everything else and are using the sod to hugelkulture the spruce and cedar stumps that still remain. These stumpkultures are between 1-4' high. It provides areas of good drainage.

What would your recommendations be for additional cover crops and soil amendments to increase minerals and ph?

Andy Cook wrote:Hi John,

We have a histosol soil on top of volcanic breccia. The soil is approximately 18", then there is a layer of the breccia gravel. This is due to our land used to be the beach 4-5 thousand years ago. The exact same gravel forms our present day beach. Our area is experiencing isostatic rebound at +- 2 mm a year. Our garden site grows grass 8' high, has wild vetch, comfrey, rhubarb, white clover. I have hand-dug "swales" and drainage ditches due to the 100+ inches of rain we receive. It is becoming more monsoonal in nature with wetter winters and drier springs and summers. We are at lat. 56. We have all the seaweed and clam shells in our "front yard that we could or want to lug up to the "back 40", along with salmon carcasses. We have planted scads of nettles, more comfrey, dandelions, clover. We are digging up the grass as it out competes almost everything else and are using the sod to hugelkulture the spruce and cedar stumps that still remain. These stumpkultures are between 1-4' high. It provides areas of good drainage.

What would your recommendations be for additional cover crops and soil amendments to increase minerals and ph?

What makes you think you have mineral problems? Usually volcanic soils have plenty of minerals. It's the lands that are far from volcanoes that have problems with not enough minerals.

As far as increasing the pH, here's a suggestion that will go one better: make a big pile of the cedar and spruce biomass, alternate it with layers of clam shells and set it on fire. Let it burn until it is glowing red coals with not much in the way of flames and then extinguish it. What you will have left is a pile of biochar with a good bit of burned lime in with it. Plus the ash at the bottom of the burn pit, don't forget that. After it cools, shovel up the biochar, burnt lime, and ash and mix that with your chopped up seaweed for an excellent plant mulch.

As far as cover crops, it sounds like brassicas should do very well where you are. Have you tried any kales or turnips as covers?

Since you only gave a small clue as to your exact location, let me make a guess. Are you anywhere near Petropavlovsk?

It's a guessing game. 56N could be Edinburgh or Glasgow. The name sounds British. Now I just need to find out if the bedrock is breccia and if glacial rebound is part of the deal there. The rate of rebound works out to about 9 inches per century so not a big altitude thing in the human time scale. Histosol soil could be from an area where there is peat. Might be a Scottish moor.

Andy --- Where do you live ?

From an earlier post, methinks Alan might be in Northland Barge, near Anchorage Alaska so even more challenging environment than you and me Dale!

I'm still getting used to this climate after more than a decade gardening in Auckland, New Zealand, but will try citrus outdoors in this locale this fall--being about 49 latitude, but some shelter from the North, supposedly zone 8b I'm told.

I liked the suggestion of Scotland tho', and if you're ever in the neighbourhood, Findhorn is well worth a visit.... Not so sure about the impact of fairies at the bottom of the garden, but they've sure grown some impressive crops over the years in what looked to me to be more akin to gravel than what I would call soil. Paul Hawken wrote about it too about 20 years or more ago, altho' he said some things then he'd probably like us to forget....

Edith

Gosh, this game is loads of fun!

We are in SE Alaska. . . temperate rainforest, histosol soil of low ph, hi leaching. Hence my thinking low nutrient/mineral availability. Love the idea of burning the spruce, cedar and clam shells. The property faces due south and is on the salt water in a protected bay. The main growing area is protected from the wind off the water and is noticeably warmer than the front of the property. A gardening neighbor has told us that livestock other than goats struggle due to low minerals in the forage. We have been onsite 4 years in the summer, so are still learning "the ropes". The rest of the year we teach overseas. Currently in India.

I grew up on a small organic farm in New England, but this is a different deal.

Andy Cook wrote:Gosh, this game is loads of fun!

We are in SE Alaska. . . temperate rainforest, histosol soil of low ph, hi leaching. Hence my thinking low nutrient/mineral availability. Love the idea of burning the spruce, cedar and clam shells. The property faces due south and is on the salt water in a protected bay. The main growing area is protected from the wind off the water and is noticeably warmer than the front of the property. A gardening neighbor has told us that livestock other than goats struggle due to low minerals in the forage. We have been onsite 4 years in the summer, so are still learning "the ropes". The rest of the year we teach overseas. Currently in India.

I grew up on a small organic farm in New England, but this is a different deal.

A-ha! Plenty of volcanoes in the area to provide the minerals, but they get leached away by the high rainfall. It would be interesting to know the depth profile of the mineral availability -- as you dig down into the breccia, are there more minerals to be found?

In addition to the clam shell bonfire, you might also want to get into the habit of taking trash with high mineral content and dissolving and chelating it, as I have outlined in my other post on composting alkaline batteries.

John, I wonder if certain rock borne nutrients could be added to soil more effectively by running them through an animal's gut ?

Chickens could be fed grit containing rock phosphate or whatever other grit contains the desired soil amendment. We'd want to ensure that they don't receive toxic levels of anything.

For adding greater quantities, I could see feeding rock dust to pigs. This would have some affect on their teeth, so the practice could be done with those who are destined for slaughter in a few months. Breeders would eat a less abrasive diet. If the rock were fed only with chopped up and moistened favorite foods, the pigs would hog it down without much chewing.

My theory is that the chemical and mechanical activities would make the nutrients more available to plants and that the animals might benefit by absorbing some minerals from the rock. Composting of manure would break the rock down further.

You make a good observation, Dale. However, rock "dust" is pretty small particles with high surface area, so in theory, the humic acids in the soil should be pretty efficient at making the minerals available for plants. Running that dust through the gut of a pig, with all the acid in the pig's stomach, probably speeds up the process, so yes, I can see where it could be beneficial. Eating dirt is a good way to get your minerals and the reason salt licks are popular with all sorts of herbivores.

But as far as making the minerals in the rocks available for plants, I have to go with the chicken as the preferred animal to process the rocks. The reason being that the chicken's anatomy mixes the rock dust with urea instead of excreting the urea separately as in the pig (and other mammals). Thus in the lower tract of the chicken, the rock minerals are being chelated with urea before being excreted, and the best way to make minerals available to plants is to chelate them with urea.

John, my friends eat these mushrooms. I need to know what type they are, in order to figure out whether there is a market. I'm able to gather them at 15+ pounds per hour. They grow in association with evergreens.

Thank you.

Look in the guidebook under Russula. The funnel shape, the depression in the center of the cap, and the abrupt start of the gills on the stalk give it away. You can find an identification key at mushroomexpert.com.

Many of the members of the Russula genus are toxic, not in the fall-over-dead way, but the make-you-so-sick-you-barf-for-hours way. Be careful you have it positively IDed before cooking them up. Most of the Russulas I run across here in Georgia are of the puke variety, so I just throw them in the wood chip mulch.