Paul Wheaton's hugelkultur article thread

oh boy, I hate stirring up trouble,  but it is so hard to resist.  The kultur part is the practice of growing food on a 'Huegelbeet'.  That is the name of the finished  plant site. Beet simply means a garden bed and is best pronounced the same way. .  It is an old concept.  As you know Germans tend to be very pernickety and  from what I gather from your pictures, though it will  work great, the average Huegelbeet builder in Germany will have conniptions. First you strip off the sod and carefully put it aside.  then you dig out the area that is to be your future Huegelbeet. Put the biggest wood on the bottom,  smaller stuff on the top, cover it all with chips if you have them, then  some old straw or hay or leaves,, put back the sod, but upside down, then cover with soil and it is ready. It settles and from year to year looses height.  I am working on a big round one right now.  also on a long one. Our very hilly place had/has a lot of badly eroded spots,  we have kind of built a dam at the lowest part  utilizing old tires, filling them with dirt. The area behind  this was backfilled with Huegel ingredients.  The first one has been in use for two years,  the second one  was in use the first time last season,  all have done great.  The biggest one is about  15 by 40.  I have layed out old boards for me to walk on.  I am still  gathering materials for the new one,of which there are lots, especially after the ice storm last year. It will be kind of roundish, about  15 feet in diameter, due to location and my physical ability. 
Btw, I did not follow the above procedure. for one, my huegelbeeet sites  had nothing growing, exept some scraggle weeds and cedar and were the sorriest site you ever saw.  there is a big, wide washout that I am in the process of filling with  branches.    what I need is a big, strong man for this kind of stuff.  I am but a simple grandma. 

Elfriede B wrote:
oh boy, I hate stirring up trouble

I think the occasional disturbance is a good thing, especially if the order that gets established afterward is good for the system. In social settings, as in soil.

Thanks for correcting me on the language! Your explanation caused some loose ends in my head to suddenly knit together, as far as the way things have been translated vs. the way non-German-speakers have used various terms.

Loan words have a long history of being mutilated as they are borrowed (look what French restaranteurs mean by the word "menu" vs. computer scientists...or the American fast food chain named "Vienna Cutlet"), but I like to be aware of the situation, and think it's probably good to preserve the original meaning where we can.

Maybe the term, as used on this thread, has been solidified in its use by the permaculture community. Or maybe we should create and adopt an English term to avoid confusion.  "Warm bed," maybe, by analogy with "hot bed?"

Gramma Elf I sure appreciated your explaination ..as it is very much what i plan on doing in my garden..but thankfully i'll be using my son's help with a tractor to move the dirt.

we are planning on kinda scraping the entire area ...not much there but some old alkaline dirt where piles of debris were burned in the past and some compost.

it will be set aside.

then the old rotting aspen wood boards will be put down where the beds will be along with some compost and manure..and then some of the dirt will be returned to the area along with some better soil that was dug out of a pond enlargement (mucky algae soil)..and then more of the compost and manure and then a little more of the soil..kinda in layers..

then it will be kinda raked into a mound (or framed in if i come up with some logs or lumber enough to frame it..which i would like to

paths will be left between these "beds" to make access easy with a wheelborrow so more ammendments can be brought in as available

one end of each bed will have a dwarf apple tree added to it..and the rest of the beds will be planted with either perennial type vegetable plants such as rhubarb, kale, chard, collards, edible flowers, herbs, etc...the rest will go to annual food crops on a rotation basis.

one of the beds will be made deeper and fluffier the first year for things like carrots, parsnips and beets..with deeper loose soil..the others hsould be able to be planted normally ,but a second looser one might be good for the following years root crop location..as i want to give the wood products a goodly time to rot before expecting to grow carrots and parsnips in them.

deeply rooted plants should help, liike swiss chard, which break up the soil down deeply..and also potatoes which you have eto dig up and disturb the soil to harvest them.

how do you deal with straighter rooted crops such as ccarrots and parsnips that need that uninhibited access to the soil for their deep roots?

For bed prep in winter, I think I wouldn't try to warm the soil first.  I would just start piling things up.  Even on top of snow.  It will warm up plenty fast.

Elfriede B wrote:
The kultur part is the practice of growing food on a 'Huegelbeet'.  That is the name of the finished  plant site. Beet simply means a garden bed and is best pronounced the same way. .   It is an old concept.  As you know Germans tend to be very pernickety and  from what I gather from your pictures, though it will  work great, the average Huegelbeet builder in Germany will have conniptions. First you strip off the sod and carefully put it aside.  then you dig out the area that is to be your future Huegelbeet. Put the biggest wood on the bottom,  smaller stuff on the top, cover it all with chips if you have them, then  some old straw or hay or leaves,, put back the sod, but upside down, then cover with soil and it is ready. It settles and from year to year looses height. 

I was so thrilled to read this. Thank you for describing how you do it Elfriede B...  And always has been done.... I now understand. Pernickity is great in places like this.... we learned something! It can be bugging for others to take your language and misuse it but I think Paul got it straight from Sepp. He does his own thing!... and sure teaches in his doing. Maybe there should be a new name that says... "above ground hugelkultur"? What would that be in German? You could help us coin a more accurate name..... 

I have been digging my beds out.... simply to harvest the multitudinous rocks that seem to fill the ground more than the soil.... and so happenstance I am doing what you describe! I fill logs in the base then lasagna sheets of green, browns, manure and sifted soil... with a larger portion of soil on top and mulch again... have a preference for bark as mulch where I can collect it.... just love the look. Going to use pee on the logs now to speed up break down like TC suggested. That is a good idea.

I also really appreciated seeing Paul's pics of urban hugelkultur... with the edging of big logs.... I think I will terrace certain beds this way where they meet the path..... because are raised higher than path level in order to effect the terrace on the slope..... all between great big boulders... so a bit different. Log-based lasagna raised garden beds..... eeeeh!.... what a mouthful! How about LLRBs for Africa!.... haha!

Chelle

Cyara wrote: Maybe there should be a new name that says... "above ground hugelkultur"? What would that be in German?

Based on my very limited understanding, the German for that might be "hugelhugelkultur," that is to say, "raised raised bed." I kind of like that translation even if it isn't correct, because Sepp builds the so very, very tall, and because it suggests "more so" in a way that I like quite a bit.

Easy to remember   

I was doing some of this today... but more like edging Hugelkultur to build up the front of a terrace adjoining a path. I really like the rustic look of it all. Be interested to see how it holds in a rainstorm. I think if enough time to settle it will.

Chelle

Are tall 5-8ft shrubs such as buffaloberry or goumi plantable on hugel kultur?

Oak logs suitable for hugelkultur? I'm aware of tannins, that's why i'm asking...

mrchuck wrote:
Are tall 5-8ft shrubs such as buffaloberry or goumi plantable on hugel kultur?

Yes.  Although I'm not sure if I would plant them at the top because then it could be difficult to harvest.

Plankl wrote:
Oak logs suitable for hugelkultur? I'm aware of tannins, that's why i'm asking...

Yes.  Fresher oaks would make a for a better border.  If you can get oaks that are already a bit rotten, that would be nice.

Thank you.

Almost forgot... i'm thinking how could one make teraces with hugelkultur. Some big rocks/stones on a hillside which could hold logs at place. Then just fill the front space with branches, small logs, soil, leaves... Not a big ass terace but it's something... i see it in nature all the time...

This is the sort of thing we do :

trying an experiment..not sure how it will work..we always have a LOT of bark off of our firewood, and hubby bags it for me..well i had a bunch and thought i'd give a try on something..so

i piled the bark down on the ground in a 4x8' area..and then had Joel dump with the tractor a hole passel of good soil down on top of the bark..to make a highish raised bed.

i'm going to likley frame in the bottom 8" or so..with some old posts i have..to hold the soil in and make it easier to reach..as i'm shortish and kinda crippled up so leaning over the tapered sides makes it a long reach.

compost will be mixed with the soil on the top of the bark..bark is about a foot deep and soil about another foot to 18" deep on top...

figure the bark will eventually rot down there..and i figure there will be a little settling as well..

thought I'd maybe plant peas or beans on top the first season..as they don't need the nitrogen that might be stolen by the rotting bark..? not really sure..no hurry as our planting season is a ways off (except for peas).

thought if this works out well i would repeat this in more beds..same size likely here and there throughout the garden..

Brenda Groth wrote:
thought I'd maybe plant peas or beans on top the first season..as they don't need the nitrogen that might be stolen by the rotting bark..? not really sure..no hurry as our planting season is a ways off (except for peas).

I think fava beans might also be able to go in.

Interesting thread. Here in Germany a few days ago our local "Gemeinde" (municipal authority) turned up at my door and shredded up four cubic metres of my old prunings. I also kept bags of leaves from last autumn and yesterday secured access to a load of horse manure. On top of that will go another trailer of freshly composted soil from the local composting centre.

It's my intention, having just received Hemenway's "Gaia's Garden" and "The Earth Care Manual" to develop a polyculture on them this summer.

Plankl wrote:

Almost forgot... i'm thinking how could one make teraces with hugelkultur. Some big rocks/stones on a hillside which could hold logs at place. Then just fill the front space with branches, small logs, soil, leaves... Not a big ass terace but it's something... i see it in nature all the time...

I would worry about holding frost in.

Roger the Shrubber it is great to have the municiple authority come over an mash up you cut branches , i have a machine but its slow,a big powerfull one would be better.
   Some gardening book i read suggested sharing a machine that gobbled up wood with the neighbors another or the same suggested a big green house for a group of neibors. Love the idea of an big green house with everyoone having their bit for their seedlings but it might be a nuiscance in reality. I have thought of a green libary for the village. I should go to the meetings of neighbors then i might get round to organising so some of these thoughts come off the groiund.
  If municiple authorities came round with machine that chewed up branches it would not half get people more interested in organic matter here, At least it seems to me that it would. What else do they do in germany that shoul dbe exported as municipal chewing up your sticks shoiuld ?  rose macaskie.

I was whatching a you tube video of Sepp hHlzer that i had not seen before and his raised beds were enormouse, bigger than him, maybe i exagerate. I imagine Brenda Groth who says she is small and crippled up standing by one, she  would need a crane to seed them. Maybe one can incorporate steps into them. agri rose macaskie.

I calculated that our ten acre forest produces above eight cords of sticks and branches each year.  Our neighbors have a procedure for "cleaning out" there properties - they pile it all up and burn it.  What a waste of biomass.  I use every bit of that wonderful stuff.

I have used Hugulkutur in my raised beds.  I just bring in the branches that fall as well as any brush I trim from the bottom twelve feet of our Farmer Trees, and I use them to either create my berms or at least to strengthen them.  Whenever I build a sheet compost, I also make sure that the bottom ten inches at least is fallen branches and brush.  The result - no waste of vital biomass, and I help to sequester carbon.
The remaining brush I cut u small enough to use in my Rocket Water Heater.

You know, brush works very well to build up the berms I've placed around my Farmer Trees.  I also have a good source of rotted Fesque Hulls that I pile up quite deep on top of the brush mounds.  The result is a berm that prevents any fertility from leaving the area where I want it to stay, as well as a great deal of surface area on which to plant my fruit trees and berry bushes.

When I bought the place I was disturbed at the very poor quality of the soil.  How could a mature forest create such bad dirt?  When I observed the dynamics more closely, I found that the fertility was simply washing away down the hill.  I've stopped that now with my Huguls and the fertility is burgeoning.

Paul. in the pictures, I don't see any cardboard being put down first. What keeps the grasses and other things growing up through the pile?

Rose, yeah it might be hard to reach if they were very high (got back from the dr today and he said i managed to pretty much ruin the tendons and ligaments in the top part of my uppber back, oh wonderful, and likely they won't really ever heal properly..great).

anyway..i have one of my hugelly beds that i buried bark in ..way too big..so you are right it is a stretch..but it will "sink" eventually i guess..that's what they say anyway.

i spent a bit of last night "googling" hugelkulture..and reading excerpts all over the internet..fun

my fukoka (one straw revolution) book arrived in the mail today..gaia's garden has been shipped..woo hooo

Sepp holzer plants trees in the dips between the hugglculture beds. That would probably be his strategy for big bushes to.
water movement in hugelkulture beds.
  He says that the water in hugglekulture beds drains down into the ditches when there is a lot of water and wicks up or moves up by capillary action  into  the mounds when there is little.
You can try capillary action by  putting the tip of a paint brush in water, the water moves up and fills the whole brush, the water molecules stick to the hairs and move up them pulling the water in between up with them and then then move higher up the hairs and pull the water higher up with them. That water molecules hold on to molecules of other types is called molecular attraction. Probably there are Wikipedia articles on molecular attraction and capillary action.
  Of course it maybe that the roots of the plants keep the hugelkulture beds damp. The new experiments measuring water flow in roots by the heat pulse method, show that in dry weather shallower roots have negative pressure, which is to say lose water to the soil instead of taking it up from the soil and then, if the plants  have a tap root or sinker roots  as bushes and trees do these deeper roots supply the shallow ones with water to make up for their loses, so water is brought up and feed to the soil by bushes and trees. This is called, Hydraulic redistribution in plants.

  It seems to me you must need an awful lot of soil to fall down into the gaps between the sticks and logs and lighter chips that go in to a hugglkulture bed or do you just grow plants on a bit of soil on top of the dead trees. farming needs plenty of base materials.

  He says with sticks and trunks in the beds serve to make beds to grow vegetables in and if he puts manure in to the beds they serve to grow mushrooms. We should ask him for more information on outdoor grown mushrooms.
plants nourishing themselves from dead wood.
  There was a time when I, lacking bits of terracotta or stones to put into my pots, to help the drainage at the bottom of the pot, put in corks and when i transplanted the plants I found their roots went to the corks and stuck to them so it looks as if plants feed directly from bits of wood.
  Also in a video on pines special to that part of the world, an island in Japan, they said the young trees seeds sprout  on  the stumps of cut ones where there are more nutrients for them and Paul Stamets who worked as a lumberjack for a while and so started an great love of forests says the same. That plants feed directly of wood is not something that to many people talk of, it seems as if there is room here for a bit of research. May it connects to the fact that they can take up amino acids as well as nitrogen in a straight form.

      Looking at Sepp Holzers videos again some of his hugglekulture beds are enormous and others much smaller. Maybe they start enormous and as the woods crumbles and sink end up normal. Doing a hugglekulture bed does feel like making a grave, and they do sink in the end I am waiting for the neighbors to dig mine up to see whose in them.

sepp lavishes cares on plants.
      How he does absolutely everything for his plants even sprinkling worms on the beds i wonder if that is necessary, which means i think it might not be. It might be one clue to his success, a real fever to do everything possible for his plants.
    When you are young you doubt your ability to work hard but it is in human nature to be creative and start having more ideas and doing more and more, so they should not worry. Videos of Sepp make him seem to be someone who is always doing more. Maybe it depends on whether or not your parents thought their little one had no faults then you become very laid back and good at getting away with a minimum, and unselfconscious about it. If you have critical parents you try to put your all into things and tend to imagine you could have done more, to never feel you have done your bit.agri  rose macaskie


 

    you see sepp holzer throwing seeds around on his terraces and hugelkulture beds, he does not say in the videos of him that are in English where he gets the seed from, I imagine he spends a lot of time collecting seed it woild be nice to see  him talking of this, mind you i have not revised all his videos recently.
      Growing your own seed used to be part of a farmers job and now we just get it from seed merchants so lessening the genetic bank for our food plants.
     How much work must go into his buckets of seeds. agri rose macaskie.

I thought I'd report in on how my hugelkulture beds went and how they're looking this spring with their perrennials coming up. My construction photos are on page one of this thread.

The bed in my pictures, I lost all my artichokes--I think maybe a hotter than normal summer followed by a really wet winter and super wet spring stressed and rotted them. There is one teeny sprout, maybe I can coddle that. BUT the strawberries and herby things all did well and came back really nice and vigorous, and are putting out nice strawberries. I only added mulch--no added fertilizer or compost etc. Mullein has shown up--not sure if I'll leave it, but then I like it....I probably will. I'll strip the bottom leaves so they don't smother the berries. Some fireweed also has migrated in from the next bed over (LOVE fireweed!)

In the other bed I did purple cabbages and roma tomatoes, along with transplanted starts of lamb's ear and deadnettle. Also transplanted an indian plum into the bed to grow as a small tree(It was about 12" tall). I confess to cramming the cabbages and tomatoes together. Cabbage isn't supposed to be a good companion plant to tomato, but they did well anyway--they each had their own side of the bed. Cabbages were about 15" apart, but grew to "normal" size(8-10" heads). Lots of tomatos, three plants in three square feet. Just remembered I also had a spaghetti squash in there, which made 4 nice squashes and a few little ones. This spring the lamb's ear just exploded--the plant that started as a volunteer little sprout is now a 3 foot diameter mat(something is feeding it!). The Lambs ear does real well at covering the ground and shading out what's under btw, and it's easy to pull. I think it looks great among the bearded irises.

I planted more cabbage in the bed this year(same spacing--seeing how long the good food in the bed lasts I guess) and also one cherry tomato. There is room for some more stuff, I'm just thinking what. Maybe I'll get some self heal going in there(it's in the mint family and a native). I put probably at least 12" of mulch on there(grass clippings and weed slash)--that's it for "compost".

I'm going to collect rotten wood from the woods and put it under the raspberries--kind of a hugelkulture on top I guess.

Hi all,  I have been building hugelkultur terrices for a few years now and have been very happy with them so far. I place logs down on contour then place smaller pine tree thinnings on that . I then add deciduous brush thinnings , a layer of woodchips to fill in the gaps and cover the heap with a layer of compost. I build it in the fall and let it sit over winter. In the spring , I broadcast a covercrop of yellow sweet clover to fix nitrogen deep into the pile. Before the clover goes to seed the following year, it gets wacked down, overseeded with buckwheat ,and is ready the perennials like blueberries, hardy kiwis, or fruit trees. If I want to put annual veggies in, I put an extra layer of soil and compost on top of the pile to keep the bulk of their root system out of the strongly fungal dominated (hence acidic) layer below.

philip freddolino your  description of a hugglekulture bed is a bit more complete than the ones first talked of, or at least is the second one i have read that talks of putting in layers of goodies, logs and then smaller type wood goodies, twigs of pine and  and deciduous trees and then wood chips , and the first that i have read that talks of a long maturing process and putting on plenty of soil for veggies.
      How big does  your bed get. I would have problem having enough compost to put on top. I have a problem getting my head round digging down enough to have a lot of soil to put on top or digging the bits in between beds low enough to have lots of earth to throw on top. I have to fight with myself to change the lie of the land a lot or to see how to do it. I also have a fight to persuade myself to do that much work. May be if you digg a deep corridor between beds you also need to calutlate for digging a wider one than i imagin or a least wide while you are digging to help you dig down.
   
    You say  the soil in them is acid because of a lot of fungal activity. You could grow blueberries on a huglekulture bed then, though your soil was not acidic or rhododendrons.
    I have planted a blueberry where i put pine chips under my magnolia, I thought magnolias liked acid soil, though  maybe this sort doesn't need them. The blueberry is doing very well and my other one, planted years ago where there aren't any pine chips,  is not,  so bits of pine bark work to acid up the soil for blue berries, though now we have put a drip on the blueberry  and as the water is full of chalk the blueberry  will probably suffer. I shall have to collect rain water for blueberries as rain water has no chalk in it. rose.

update on the two that I built last March.

The first bed has potato, melon, corn, bush beans and a few onions growing in it, they are growing very well.

The second bed has one apple tree, some squash, several tomato plants a rhubarb, and several lambsquarters growing in it, all are doing well, the dwarf apple seems quite happy there.

Also we had a wood pile a few years back when we had branches pruned out of a large ash tree, a lot of the smaller twiggy branches have laid on the ground for about 5 years now..and this afternoon i gathered up 3 wheelborrow loads of them and i've decided to toss them into a pile where compost is being put, as well as some char and ash from our wood furnace from last year..this is in a clearing in front of our woods but behind our walnut tree babies..also there is a pile of quackgrass sod nearby.

I'm thinking of throwing more compost material on top of the 3 wheelborrow loads of rotting twigs, and then having my son drive over it with the tractor to where there is some pond muck soil piled..and have him back blade that back over the piles when they are formed a few feet deep..and then i'll plant that area with some of the walnut guild plants that I have planned for that area..maybe next spring..in the meantime all the extra rough stuff will be throwin on that pile area.

as it is actually IN the woods, barely, it will be receiving leaves and twigs from the woods in the fall this year as well..and i have some rotting aspen trees and branches that can go int here..and am thinking of chipping up a pile of branches that i have nearby as well.

this area is probably 15 x 20 area..wondering if i should have Joel scoop it up into a more compact pile before coverig it with the pond muck..I'd really rather have it a lower spread out pile i think then a really tall pile.

  phillip fredolino making hugglekulture beds will be much easier if i dont have to build trenches.
  Are you teasing me? i copied out a good bit of what you said i  find it easier to pick things up if i read them several times, mind you if its informaiton you have pretty wel taped it can seem a bit uneccessary. I was arguing with myself about whether to repeat you or not and you have printed out my answer and now all those for who this isnnew will have it repeated three times . It is getting funny.
      Writting about having enough compost to throw on top of the sticks and chips and such of a hugglekulture bed has made me think maybe one could buy up some mouldy hay or straw to lay up and let rot, to make sure of having lots of compost to top the huglekulture beds with. you could put  plenty of fertiliser on it to get it rotting quicker. I have lots of sticks and trunks but no compost to speak of. My hay is what Susan Munroe would call poor thin hay and the places it grows on need it to better the  soil were it grows.

      Brenda Groth. Having a son with a tractor is a definate winner if you want to have some real big Sepp Holzer huglekulture beds. Then it would only be buying the steps to get up to the top of them.
  Seems like you have all the books i have to get myself but i have to get a little bit of work done on sorting out my accounts and opening a online account like pay pal, instead of going on writting here. It is so much easier doing things i habitually do than things i seldom do.  I think all children should be told that it is horribly hard doing everything you aren't used to doing, from the very simple, like boiling an egg to more complicated things like tax returns. but it is possible.rose

Rose, nope i'd rather not have steps up to my beds..i'd actually rather have them no more than say 2 or 3' high, or less maybe.

This new area will cover a larger area of ground and not be so deep, i think this will work for what i want to do here..and there is a large mix of what is getting thrown onto the pile before the dirt will be put over it. However this will be part of the walnut guild area, as it will all be north of the walnuts and under the dirp line of them, so i will have to be taking things from my "play well with walnuts" list to plant in this area..and i'm thinking of fall planting it,, working on building it over the summer.

Fascinating stuff - since we harvest wood, you wouldn't believe the amount of slabs we end up with. The workers, like usual, are going to be convinced I have lost my mind when I tell them to stack them. We also have a huge amount of sawdust, etc. I can see creating a huge structure like this below the wood factory, piling on sawdust and horse manure (we trade sawdust for horse manure, cow manure, chicken manure, etc.) and then just throwing seeds onto the pile and planting things like papa chinos.

We already have some of the best bananas you have ever seen growing where the sawdust comes out. I never get any (I have my own) because the workers take them home.

Having a backhoe, it should be easy to do the work.

absolutely fascinating. thanks y'all.

wish you were closer, sawdust and woodchips are a big $ commodity here now with the bioand co gen plants burning wood waste..you can't get it for your gardens without paying a big bunch of $

What is the effect of rotting wood on piles PH? We already have acid soil, would adding biochar help to balance the PH?

I think most deciduous wood makes soil pH more basic.

I led a hugelkultur workshop a couple of weeks ago.  Here is some video from it:

everywhere that I have begun to bury any woody materials on my property the improvement has been notable. One thing I did notice was an increase in earwigs, however the birds seem to be handling them nicely. I believed that seeing the increase in earwigs meant that all the excess rot-ables were getting attention that they required from the insect world, and the over abundance of insects didn't really do much garden harm, and I now have really fat birds.

A friend of mine saw the video and emailed me to say that he had something like that that was ten years old.  So I popped over to his place and took this video:

Doing some homework this AM, studying up on this Hugelkultur thing, trying to wrap my brain around how it works.  There is not a great deal of information online.  I think this is an area which has seen far less investigation than it deserves. 

The how-to is simple enough, well covered in this thread and Paul Wheaton's Hugelkulture page:  Dig a hole if you like, add wood, cover it up with some combination of soil, leaves, compost, or whatever else is available.

I'm looking for answers to the question: How Does It Work?  From what I'm reading, the hugel beds work in several ways which promote a healthy soil ecology.  I'm also coming up with more questions.

Water Retention
The ability of dead wood to absorb water is well documented.  Water would be available to plants with roots long enough to reach the wood layer, or close to it.  Hugel beds would be resistant to drought, giving the plants growing there a survival advantage. 

Nutrient Trap
Being buried to a depth of a foot or more, the dead wood is ideally placed to absorb and retain nutrients which would otherwise leach out of the soil.  I live in north Florida.  My soil is a quartzipsamment entisol: sugar sand, all the way down to the center of the planet.  It holds no water or nutrients.  Water drains at a rate of 6 inches per hour.  Irrigation only promotes nutrient leaching.  Seems to me a hugel bed would be well suited to my conditions, absorbing the water along with its dissolved nutrients.  I have to wonder what the result would be if a hugel bed was first lined with gley. 

N
While the initial bed would see the wood consuming some N, this would be bacterial activity.  Once the N is depleted, do those bacteria die off allowing fungi to take over?  The fungi would release N from the wood and the wood would capture whatever N leaching out of the soil above.  N is retained rather than lost or depleted.  This line of thinking could use further development and understanding.

Nutrient Resource
Along with the captured/trapped nutrients are the products of the wood decomposing.   I found the abstract for a paper ($34) showing rotting wood with nutrient values of N (0.18–1.29%), P (0.12–0.56 mg g−1), and K (1–23%).  About the same as compost, but with a MASSIVE amount of K.

Mycorrhiza Activity
Fungi would be the dominant component of decomposition of woody debris, with mycorrhizae finding an optimum environment.  While the pH would tend to be less acid, making P less available to plants, mycorrhizae would be able to chelate nutrients in areas where the pH is not ideal for the plants.  The range of pH in which plants could thrive would be greatly expanded.  The plants provide sugars to the fungi, the fungi provide the plants with mineral nutrients.  It does not matter that the plants cannot access the nutrients in the rotting wood, the fungi will spoon feed it to the plants.  I think the involvement of mycorrhizae in hugelkulture is a key aspect to how it works.

Compost Amendment
When burying the wood, I think adding some amount of compost would provide the source of fungi which innoculates the hugel bed.

Wood Layer Thickness
How deep a layer of wood is good?  More seems to be better, but should I go with 2 feet thick or can I get away with 1 foot thick and get twice the area out of the same amount of wood?   How thick can I pile the wood before there is no further advantage (diminishing returns)?

Topsoil Thickness
For shallow rooted crops, a foot of soil on top of the wood would allow roots to reach the wood.  For deep rooted plants, 2 feet is about right.  I think that burying the wood deeper would start removing the nutrients from the reach of some plants.  I'm focusing on vegetables, so 1-2 feet of soil depth over the wood seems about right.

Some questions
How long does a hugel bed last before it needs to be rebuilt?
Are some types of wood better than others?
Are some types of wood better for different soil types?
Are some types of wood better for different crops?
Does the direction of wood grain have any effect on the system?
Is there an advantage or method for preparing the wood before burial?