Mulch

[SIP Gro-Tubs]

Originally Posted by Durgan

My underlying soil is heavy clay. In the small cultivated area (about 1000 square feet) 100 cubic yards of compost has been added over about 8 years. About 8 cubic yards of wood chips are added each year. One year I added about 5 yards of washed mason sand to inhibit coagulating of the compost\clay mix. I notice even after 5 years this sand is still obvious.

My initial concern was to break up the clay. Eventually it was found that compost does the best job of making the clay friable. The wood chips are icing on the cake.

The combination of wood chips and compost are considered indispensable, and both must be added yearly. I also like a cover crop, of red annual clover but I cannot afford to allow an area so small to be idle while it does its miracle so usually don't grow the cover crop-meaning the season is too short.

Fortunately, I don't have any rocks. A downside is there is no water table. Two feet down is almost a cement base and no water permeates. All my water comes form the surface, which can be a misery in a very dry year. No wick effect for me.

Gypsum is the best for making clay friable.

[Durgan]

Originally Posted by SIP Gro-Tubs

Gypsum is the best for making clay friable.

Gypsum use is totally dependent upon the type of clay. It is useless on most of the NA clay soils. It does have its uses in places like Australia and possibly some NA pockets.

http://buckeyeturf.osu.edu/index.php...968&Itemid=170
Questions have trickled in recently about "gypsum" as a soil conditioner for heavy clay soils in Ohio. Gypsum is traditionally applied to soils that have high levels of sodium (Na). High sodium, or "sodic" soils lose structure and have very low water infiltration rates. Sodic soils also become very hard when they are dry. When gypsum is applied to sodic soil, it displaces, or knocks the Na off the clay soil particles. The Na is then leached out of the soil.

Sodic soils in Ohio are very rarely seen. In 10 years of Extension visits I have seen only one site in NE Ohio that had elevated levels of sodium in the irrigation water. With that in mind, there really isn't any benefit to applying gypsum to heavy clay soils that do not have a sodium problem. Amending with good quality topsoil and organic materials like compost will offer much more benefit.

[COMPOSTER]

Amazing that you have put 100 yds of compost on 1000 ft of garden bed. I call that true dedication to soil improvement. Compost is miraculous stuff. I feel it is indespensible also. The interestnig thing is that I use a lot of compost and other organic matter to improve a sandy soil and you are using it to improve a heavy clay soil. Really fantastic that nature has what both of us need. There was someone in another thread that was looking to improve heavy clay soil. I hope they take the opportunity to read this thread. What do you grow besides tomatoes?

[Durgan]

http://durgan.org/2011/ Journal

[dice]

Do you amend the soil with the mulch at the end of the season or
the next spring before planting? (I suspect that is why using rotted
wood chips that have composted for a year or more is a better
idea than mulching with fresh wood chips, to minimize nitrogen
drawdown when the soil is amended with them.)

In a research report from somewhere in North Africa (Sudan or Chad
I think), soil was amended with hardwood chips, and yields were
measured against plots that had not been amended. In the first year,
yields dropped by half in the plots that had been amended with wood
chips. In subsequent years, year two and beyond, there was no loss
of yield in the wood chip amended plots compared to plots that had
not been amended. Both kinds of test plot had the same fertilizers
applied (whatever the farmers normally use there for that kind of crop).

Composting also moves the pH toward neutral, whereas uncomposted
wood chips tend to lower soil pH. In neutral to alkaline soils, this is not
such a big concern, and it may actually be a benefit in alkaline soils.
In soils that are naturally more acid, amending the soil with uncomposted
wood chips may also raise the amount of liming that is needed.

This document suggests meeting additional nitrogen needs of wood
chip amended soil with sulfate of ammonia (which also lowers soil pH):
http://www.klickitatcounty.org/solid...cted=178631264
(I might use calcium-nitrate instead, adjusting quantities as necessary
to get comparable nitrogen inputs, although nitrate leaches out of
the soil from rain faster than ammonia. After a couple of weeks in
the soil, bacteria convert the ammonia to nitrates anyway, so this
difference in leachability does not last long.)

Where one is not amending the soil with the wood chips, using them
only for mulch and raking them out of the way before adding soil
amendments, composting them probably does not provide the same
benefits that it does where the soil is amended with them.

[Stvrob]

Around here they chip wood to send to the paper mill. Generally no bark, twigs-just slash pine chips. I don't use that because its a nitrogen hog. On the other hand, the the stuff the utility company removes from the electrical easements, chipped and shredded, with higher proportion of bark/twigs/leaves, I have no problem with that. It heats up like real compost, and if they are working down the road they are glad to dump it on my property for free.

[COMPOSTER]

Durgan,

I would like to sincerly thank you for starting this thread! I am in southern New England and have had 5 out of 6 days of rain and wind. Tomorrow is supposed to be the same. I am 1 week behind in my planting and feeling disapointed that I can't plant my seedlings and seeds. But as you well know gardeners who are working to produce a lot of our own food have got to keep moving forward or we will end up going to the farmers market instead of our own gardens for food. Your posts gave me the incentive to go out and pick up about 3 yds of wood chip mulch that has been in piles on my very own street. Literally 30 seconds out of my driveway I can pick up hardwood and softwood mulch that has been left on the ground from trees that have been cut down near power lines. I used the wood chip mulch around 6 Blueberry bushes I planted last year.

Bottom line: Instead of sitting inside and complaining about the rain, wind and cold, I got a little wet and did something extremely productive that will improve my soil and save me a lot of time weeding.

Glenn

[Redbaron]

Originally Posted by dice

Do you amend the soil with the mulch at the end of the season or
the next spring before planting? (I suspect that is why using rotted
wood chips that have composted for a year or more is a better
idea than mulching with fresh wood chips, to minimize nitrogen
drawdown when the soil is amended with them.)

In a research report from somewhere in North Africa (Sudan or Chad
I think), soil was amended with hardwood chips, and yields were
measured against plots that had not been amended. In the first year,
yields dropped by half in the plots that had been amended with wood
chips. In subsequent years, year two and beyond, there was no loss
of yield in the wood chip amended plots compared to plots that had
not been amended. Both kinds of test plot had the same fertilizers
applied (whatever the farmers normally use there for that kind of crop).

Composting also moves the pH toward neutral, whereas uncomposted
wood chips tend to lower soil pH. In neutral to alkaline soils, this is not
such a big concern, and it may actually be a benefit in alkaline soils.
In soils that are naturally more acid, amending the soil with uncomposted
wood chips may also raise the amount of liming that is needed.

This document suggests meeting additional nitrogen needs of wood
chip amended soil with sulfate of ammonia (which also lowers soil pH):
http://www.klickitatcounty.org/solid...cted=178631264
(I might use calcium-nitrate instead, adjusting quantities as necessary
to get comparable nitrogen inputs, although nitrogen leaches out of
the soil from rain faster than ammonia. After a couple of weeks in
the soil, bacteria convert the ammonia to nitrates anyway, so this
difference in leachability does not last long.)

Where one is not amending the soil with the wood chips, using them
only for mulch and raking them out of the way before adding soil
amendments, composting them probably does not provide the same
benefits that it does where the soil is amended with them.

If the chips are too "brown" you simply mix them with "green" mulches to balance them out. In my case that means mixing them with grass clippings which are high in nitrogen.

[Durgan]

http://www.backtoedenfilm.com/#movie BACK TO EDEN Film


Gardening with wood chips. Worth a look if nothing else.

[Durgan]

Originally Posted by COMPOSTER

Durgan,

I would like to sincerly thank you for starting this thread! I am in southern New England and have had 5 out of 6 days of rain and wind. Tomorrow is supposed to be the same. I am 1 week behind in my planting and feeling disapointed that I can't plant my seedlings and seeds. But as you well know gardeners who are working to produce a lot of our own food have got to keep moving forward or we will end up going to the farmers market instead of our own gardens for food. Your posts gave me the incentive to go out and pick up about 3 yds of wood chip mulch that has been in piles on my very own street. Literally 30 seconds out of my driveway I can pick up hardwood and softwood mulch that has been left on the ground from trees that have been cut down near power lines. I used the wood chip mulch around 6 Blueberry bushes I planted last year.

Bottom line: Instead of sitting inside and complaining about the rain, wind and cold, I got a little wet and did something extremely productive that will improve my soil and save me a lot of time weeding.

Glenn

Sure beats watching a re-run of CSI.

[ArcherB]

Austin TX shreds Christmas trees every year and makes the available to the public in large piles. All you have to do is drive out there and pick it up. The hardest part is getting out there at the right time as it's only available for about a week. It also helps to have a pickup.

I've put down three to five truck loads a year for the past few years. Unfortunately, my results have not been as stellar as what everyone else here says that they are receiving. Without adding compost and working the soil, the soil doesn't do very well. Maybe all the good stuff washed away... who knows.

Last year, I amended and worked one of my two beds and thought I'd try the "no till" method in the other. In the bed that was amended, I add about a yard of composted rabbit manure and a year's worth of compost (grass clippings and kitchen scraps mostly) and worked it all down about six inches. In the other bed, I did nothing but pull weeds. Both beds received about six inches of the Christmas tree mulch. I received about 125 lbs of tomatoes from the bed that was worked and about 20 lbs from the bed that was not. Also keep in mind that the "no-till" bed is on the north side of my yard which is surrounded by a wooden fence. That means that early in the season, the "worked bed" is in shadow as it's on the south side next to a wooden fence. Usually, the North bed does much better.

This year, I added compost and worked both beds before adding the Christmas Tree mulch. Also, on the north bed, I scraped off the "good stuff" and dug up about six inches of the ground beneath and threw it away. It was mostly red and black clay. I filled it back with compost and stuff I scraped off. My hope is that this will prevent the compost I've been adding from washing away. Already, the north bed has outproduce what it did last year. The South bed hasn't taken off yet, but it usually runs about a month or two behind the N. bed.

TLDR? Adding just wood chips hasn't done it for me. Compost must be added as well.

[Durgan]

http://www.durgan.org/URL/?OXMVP 30 May 2013 Vegetable garden mulched with wood chips.
The vegetable garden was mulched with wood chips.The layer of chips is about three inches. When any new seeds are planted the mulch is scraped aside and creates no problem.The purpose of the mulch is to inhibit moisture evaporation due to a hot Sun. Secondary is weed suppression but not particularly effective.

[COMPOSTER]

Originally Posted by Durgan

http://www.backtoedenfilm.com/#movie BACK TO EDEN Film


Gardening with wood chips. Worth a look if nothing else.

Watched the first 20 min on my lunch break at work. Loved it. Watched the entire movie last night. Now I understand the wood chips. I use them around a couple of my beds and I always worried when we had heavy rain and some washed into the beds that they would work themselves into the soil and rob my plants of nitrogen. I'm not worried anymore. Thanks for turning me on to the movie. It's definately worth watching it again. As I said in a different thread, learning from others experience is exactly why I joined this blog.

Glenn

[TZ-OH6]

I treated my hardwood chips with urea to partialy compost them before working them into my clay. It was nearly pure clay from under the topsoil layer too. It worked ... about six inches of chips into six inches of clay and it is friable soil now, and is dark brown instead of yellow when worked. It will never be smooth enough for long carrots but it grows most everything else. Fungal activity in the soil working on partially composted wood creates chemicals on the fungal cell walls that help soil texture more than adding finished compost would after the microbes are done with it.

My regular clayish topsoil (central Ohio farm soil) does not seem to change with the addition of grass clippings and leaves year after year, which are mostly cellulose. Wood chips have a lot of lignin which turns into long lived humic compounds. That and the calcium interact with the charged clay particles and keep them from sticking together in acidic soils.

Humic compounds have nitrogen locked into their stucture so if you do not have the nitrogen available then microbes will simply burn down the carbon into nothing. But stable soil humics last 10-15 years.

[dice]

Not all research with wood chip amendments found that soil pH
dropped after adding the wood chips. It depends on the kind of wood.
Amending a high pH (8.7 native pH) soil with pecan chips, for example,
found no change in soil pH from the wood chips alone. Some kinds of
wood chips (I do not know what kinds, this was just a general statement)
even raise soil pH. Adding sulfate of ammonia as a nitrogen source to
mitigate nitrogen drawdown from the wood chip amendment definitely
reduces soil pH, though, regardess of what effect the wood chips
themselves have.