Chris McLeod wrote:Hi!
Mulch is great, but what you are finding is that the top layer of the mulch is exposed to the UV from the sun and has formed a hard outer layer. I think what happens is that a waxy enzyme forms to bind the mulch together and the UV bakes the outer surface. Also mycellium threads start to form deeper in the mulch. All of these actions prevent the mulch from running away (erosion) with the first big rain storm.
The bonus is that you are starting to create soil and retain long term moisture and this is an early stage with mulch.
What happens next is that pioneering plants get established in the mulch (some may call these plants weeds, but pioneering is a better name). Let these grow and then when they die off, cut them back and drop them onto the surface of the mulch.
Your soil will really start to get going now.
Michael Newby wrote:Stones are great tools when used properly in the landscape. Windbreaks, thermal batteries, solar collectors, all kinds of things. Big stones sticking out of a pond will help keep it from freezing as winter starts and thaw it out earlier when spring comes around. Loose rubble walls/piles of stones have been shown to act as dew collectors and can help add moisture to the surrounding soil.
How thick are you applying the wood chip mulch? For initial soil building processes it's been my experience that you want a good thick layer - I've gone as deep as a foot. This gives enough mass that even if the top inch or two dry out in the dry season, the lower layer in contact with the soil stays moist. This moist area next to the soil will begin to foster all sorts of beneficials that will start the true soil building cycles. Many of these will form a biofilm that will greatly increase the chips water holding capacity and resistance to drying out. Mycelium will help transport water an nutrients through the chips and soil. Both of those things help to bind the chips together like Chris was saying. None of this will happen if the chip layer is too thin and dries out completely.
Michael Newby wrote:Owning a tree service, I have large piles of wood chips that I get to watch break down and I am always amazed at the activity you will find as you dig down into the piles, even a pile that's only 1 month old and been in the 90-100 deg summer days, as long as the chips came from green wood so they already have some internal moisture. I can dump a pile of chips on bare dirt and as long as the dirt isn't toxic in some way there will be loads of tiny little earthworms near the edges of the pile at the soil/chip interface. These guys don't start to flourish because of the wood chips specifically, but because all those new little microorganisms that are starting to flourish are great fodder for the worms. .
Michael Newby wrote:
Instead of going through the trouble of removing the woody stuff, you could probably get some good results by putting a layer of leafy/twiggy mulch over it. This will add to your overall organic material and provide what I think might be keeping your woody mulch from breaking down - better moisture absorbtion/retention and a broader spectrum of food to support a broader spectrum of beneficial micros to break down all the material. The more diversity the better, especially in the soil. My wife always laughs at me because I'll get excited when I see a new color slime mold or LBM pop up on a pile of chips but there just signs of increasing diversity in the chips.
Michael Newby wrote:While the Mt. Shasta City does get a decent amount of precip, the land to the NE of the mountain is in the mountain's rain shadow - Mt. Shasta is a hulking volcano that juts almost 11,000 ft above the surrounding countryside so it really causes helps to create a variety of "large" micro-climates. For a better idea of the weather in the area Montague is a close match with an average of ~13 in/yr. The high dry areas are nothing but sage brush and junipers. We're not quite as high in elevation, but the August temperatures regularly hit the triple digits while dropping back into the 50s or 60s at night. Winter temps tend to be in the 20s and 30s with the chance for good variation. One thing we fight here is a lot of wind - good for turbines, bad for just about everything else.
Sounds to me like the main problem is getting the chips initial moisture content up and kept up long enough for things to start happening. Any way to maybe hook some buckets up to soaker hose running under the mulch? You could fill the buckets up as needed during the first year and the soaker hose would put the water down where it was needed. You could even set up rain water collection to help fill the buckets when it does rain enough.
Do you have any chickens? They love to dig around in the chips in search of goodies and their poop really seems to help activate the chips.
S Bengi wrote:Most desert soils are ultra fertile in that they have alot of minerals and so they dont really need much help on that.
What they do need is ways to break up the soil in various stages of "hardpan".
I think that creating dimples with a stone near the center, is the best way to go.
In arid place the soil/humus is really created by fire "bio-char"
So I would start a worm composting bin to buildup humus.
Use nitro-fixing living mulch in the sun, and use regular mulch only under tress maybe.
S Bengi wrote:This is what I have in mind http://www.permaculturenews.org/2012/09/19/imprinting-soils-creating-instant-edge-for-large-scale-revegetation-of-barren-lands/
The stone would be place 1/2 down the slope to condense dew at night and hopefully the dew would run down to the center and then soak in.
Tell me what you think of the link above.
Paul Gutches wrote:
I am entertaining trying some living mulches.
What is your general location?
Do you have any experience with the following?
Chris McLeod wrote:
I forgot to mention, it would have been optimal if you had deep ripped the soil before applying the mulch. I've tried this over a large area using a 20 tonne excavator and now have some awesome herbage growing there only 2 years later. I've also tried this on a small scale by digging holes by hand about a foot wide (300mm) and about that much again deep about 6 to 9 foot apart (2m to 3m) when I planted out the food forest here (over 300 fruit trees). Mulch was then applied on top of this and also mixed into holes with the fruit trees (clay / mulch mix).
Chris McLeod wrote:
The soil was originally hard baked volcanic clay and the rain just ran over the surface washing away all accumulated organic matter year after year. I'm at 37.5 degrees latitude south (Down Under) at elevation and have cool wet winters (never below freezing, but the occasional snowfall) and hot dry summers. It is almost 40 Celsius outside today (104 Fahrenheit) in the shade and we're having a heat wave for the next week or so.
Chris McLeod wrote:
The reason I mention the deep ripping or just breaking up the clay a bit is because the water is stored in the clay rather than the mulch. The mulch acts like an insulation blanket against the sun and cold and reduces evaporation thus starting the soil processes. It has been my experience that if you don't break up the clay, then you need a lot of mulch in a thick layer. Occasionally, like in my strawberry bed the mulch can be about 1+1/2 foot deep (0.5m). When it is this deep, the soil life does the digging for you and will break up the clay and store water.
Your mulch is most likely drying out and a dry environment is not good for the fungal growths (mycellium) which will turn the mulch into soil. You could try applying water to it regularly during the summer months to experiment and see what happens. You could also try getting in plants with heavy duty roots such as alfalfa during the cooler months to break up the soil a bit too.
Chris McLeod wrote:
I tried fenugreek here this year and it is dying off in the dry...
White and red clovers are really hardy and do well here.
Vetch has finally self seeded here, but pops up in Autumn and dies off in early summer leaving a lot of seeds.
Wild lupine - I think I call these Russell Lupins? They put on a great show and are really prolific self seeding plants here (I just picked up a pack of multi-colour Lupins)
The rest I don't know about.
California poppies are prolific self seeding plants and also really drought hardy.
Geraniums (pelargoniums) and olives are real givers in very hot dry summers.
Apricots once established are very drought hardy.
Chris McLeod wrote:
Try also maybe growing some fruit trees from seed as they will have much larger root systems than the grafted trees which can be a bit stunted. I've been experimenting with these here and they seem to be pretty tough.
The photo below was taken just after Christmas which is high summer here!
Kelly Smith wrote:Hi Paul,
I am just a few hours north of you in Colorado, and it sounds like we are experiencing the same issues, with similar soil types.
I wanted to add a few things that may help:
if you cant get a ripper, you may try to find a broadfork or other hand tool that will loosen up the soil by hand (depending on the size your breaking up). i think the main goal is to break up the hard top that forms on clay soils that have been exposed as this speeds up/helps water get into the soil, vs being held in the mulch. we didnt do this before we mulched, but i will be giving it a try on a small scale this spring to see how it helps.
in my area, hairy vetch seems to be the vetch that does the best. alfalfa also does good here once established (in irrigated fields it does great)
i would like to find a good living mulch that will grow in our area. something that can be chopped and dropped would really help the mulching come alive, imo.
good luck and keep posting updates
Chris McLeod wrote:Just read all of the comments. Very thoughtful replies.
The other thing that works well here is shade. A lot of our rainforest plants here are incredibly well adapted to heat and drought and are worthwhile in creating shade and building organic matter in the soils. Black wattle (acacia mearnsii) and Blackwood (acacia melanoxylon) are both good shade providers, leguminous and provide outstanding timber. They've become something of a weed in other parts of the world (South Africa as well as other spots).
There are plenty of other plants too (carob etc) which perform similar functions. Have a look at the Greening the Desert project - if they can get a food forest started there...
Fire changes the soil ph here too (makes it more basic) which can be a real problem for the diversity in the forest. I'm unsure about how this cycle actually works in all the fine details, but the eucalyptus trees here benefit from wiping out the competition for sure.
S Bengi wrote:A hard pan a few feet under the surface is very bad. A hard hat an inch or so thick AT the surface is nothing more than a dirt mulch.
It stops evaporation/water loss, however you dont want runoff taking water leaving your property.
So it would be good to have that water run to a depression that has a tree/plant in it. Thus double your effective rainfall.
Devon Olsen wrote:paul, ive impatiently read through the entire thread reading all that it has to offer and am glad i did
i am currently working on a land in cheyenne wyoming, and though the soil is different, mostly sand, about a foot of "topsoil" and rainfall about the same, about 12 for most of the city, the site is located in the center of a circle of drought though and gets about 9-11.5 inches a year, with many storms raining/snowing all around us but completely ignoring our property
i mulched a small potato plot this year and a few other spots and though i didnt go very thick, just an inch or two, i noticed the same sorta thing, immediately after a rain, the top 1/8inch of woodchips would absorb moisture and look great, but digging down revealed a dry, dusty soil and yielded poorly, even weed had trouble growing there, i am hoping it will eventually break down and these effects will be reversed but i looked to the rest of the yard and asked myself how the native grasses managed to mulch themselves each year without drying themselves out
and the answer appeared to be that though there is mulch, there are also mottled spots of exposed soil, though these spots do evaporate faster, they also allow immediate entry of moisture into the soil, an island of bare soil, surrounded by mulch, the soil didnt really get a chance to erode heavily and i hypothesize that moisture is able to enter the soil and then be protected by a net of mulch, rather than a sheet and is hence slowed in evaporatio0n while allowing moisture to enter during our more frequent rains that total perhaps a 16th of an inch of moisture
Devon Olsen wrote:
where i had the main pile of woodchips however, about 3-4ft thick, the bottom of the pile formed into about and inch and a half of extremely rich, moist, dark brown soil that i am sad to report i had no seeds or season for when i moved the pile out of my way
Devon Olsen wrote:cant wait til you do start a thread fir experiments, post a link and ill make sure to follow along and pitch in my two cents for ya from time to time
and im gonna have to look for that round stalk thing, ive never thought look for such things during observations so ill keep my eyes peeled
interestingly the pile was on a slope so there was no collection due to any depression, and even during the heaviest rain we had (if i had to guess id say a whole inch or so at a time) it didnt penetrate more than an inch
i think the moisture can entirely be attributed to fungi, bacteria, worms and soil contact and had little to do with rainfall other than that small amount that would have been necessary to support life
it was comprised of multiple species from what i could tell, im pretty sure it was fairly local so if i had to guess id say it was mostly pine and cottonwood though it could have been other species as well, those are just the most popular trees in the area that people have planted (the cheyenne area had no trees for miles upon miles when people first started settling from my understanding, so every tree is a result of human activity)
it was also stacked downhill and touching a pile of imported horse manure, so there may have been some nitrogen leached into the pile from water moving along the ground
both piles were imported in the spring and moved in the fall so it was only one summer, not even any snow to slowly work its way into the pile, just the few rains that do as you say and kind of run off the pile rather than soaking in
definately interesting stuff to observe, thats for sure
Morgan Morrigan wrote:
So you are backing up the hill, doing filled swales, and end up with what looks like contoured field of row cropped rocks !
Chris McLeod wrote:The other thing that works well here is shade.
Andrew Parker wrote:Desert soils will seal up under a deluge, dumping the water off quickly into arroyos, but melting snow will soak in much deeper.
Paul Gutches wrote:
I always considered living mulches to be low growers. It would hurt your back if you had to chop and drop them!
Andrew Parker wrote:Have you researched keyline farming and the Yeomans plow?
Chris McLeod wrote:
his is a before shot of the same area from October 2009 showing the trenches for the worm farm being put in.
Andrew Parker wrote:Paul,
Many keyline projects I have reviewed on the internet were on moderate slopes...
A quick search located a permies member, Owen Hablutzel (owen (at) permacultureusa.org), in New Mexico who specializes in Keyline and the Yeomans plow..