grass immobilizes nitrogen?
Miracle Grow Garden Soil - problem?
Vortekker, I believe anything composting will temporarily tie up the N. That's why instructions always say, " well-rotted manure" or "completed compost" That would mean the process is close to finished and no longer needing to use the N so it would not be stolen from your plantings.
I thought green grass clippings contributed nitrogen.
Im not an expert. I just happen to be a night owl. My understanding of composting is that the microbes that do the work of composting need carbon (brown things), Nitrogen, (green things) and Oxygen, (turning the pile to aerate) to live, just like we do. Alot of the brown things will eventually be broken down (metabolized) by the microbes, giving off CO2. That means some of the brownies go up into the atmosphere, just like when we breathe. The Nitrogen will remain about the same in the pile as the microbes die leaving their N for the next generation of microbes to use. We start out with about 30 to 1 ratio of brown to green and end up with about 10 to 1 ratio of browns to greens, or carbon to nitrogen. Since the micro-organisms need these things to live, if we dont have all the ingredients needed for them to live, the composting doesn't do much.
As you can see the N is "tied up" temporarily inside the microbes but when nutrient supplies are used up, the microbes die, giving the N back to the soil. If you put uncomposted material on your garden, for a while it will add no N to the soil because the microbes dont release it until they die. If a material is composting, it means the microbes are comsuming Carbon, Nitrogen and Oxygen from the materials. If the N is being used to compost, it is not available for your plants to use until the composting is finished. The microbes also generate heat energy as a waste product of their consumption of materials, just like we do and all animals do.
Hope this helps. Cam
Well Al I'm slowly coming around on this thinking about the saw dust. The fines don't seem to have any bark residuals and there are some small chunks of wood in the mix. When I added this to the fresh horse manure I placed in one of my compost bins it seemed like a good mix. I plan to turn this material today and see if it is ready to start my first raised bed. Usually it take months to break down the horse manure in this bin without any other additions other than a bucket of red wigglers and it never seems to get very hot. What I intend to do in the first raised bed is lay down a layer of wood chips and place this horse manure/wood chip fine mix on top of that. Then I will add the final layer of growing mix. The growing mix will consist of recycled. Grated soil from the raised bed and some well aged cow manure/straw mixed in. I have located a source of fine washed sand which I am considering adding as well. The wood chip fines...well I don't know. I would appreciate any and all input on this idea as well as a suggested formula for these three or four ingredients in the growing media.
morgan
Vortrekker, I think the point is that you cant feed plants and compost at the same time with the same material, unless the material is composting very slowly like a bark mulch that gradually composts around your shrubs over a long period of time. The plants and the microbes would be competing for the same nitrogen. If you put grass clippings on your garden, it WILL compost, no way to stop it except to sterilize the soil which you would not want to do if you are going to grow in it.
Cam,
I've seen the term "Nitrogen is 'tied up'" scores of times around the garden, but this is the first explanation of what it means, and how it works, that I've ever seen OR understood! Great job, and thanks a bunch!
Linda, who now understands why the compost pile is heating up in the first place (all those little microorganisms throwing off all that energy munching on the good stuff), why the plants have to wait until the microorganisms die to benefit from the good stuff the microorganisms leave behind (cause the nitrogen is finally released into the compost), and why I shouldn't be setting up the competition in my garden in the first place! (because the microorganisms will win temporarily, until they die, and my garden will suffer while waiting for some nutrients!)
"By, Cam, I think she's got it!!!!!" ^^_^^
Been so busy - just came back to ck on this thread & there is nothing I can add to what Cam said. Very good job explaining - you should take a bow!
Al
Cam,
There's a gardening dictionary here in Dave's Garden. Do you mind if I add "Nitrogen-tied up" to the definitions for future users -- I'll use your name? Or, you can add it yourself!
Now. Is "fixing Nitrogen" the same thing or some other process? If not, please explain what it means.
Hugs!
Fixing nitrogen refers to a symbiotic thing going on with plants and some fungi- let's just not go there, here !
Gym--
"nitrogen fixing" is usually reserved for the process of legumes taking nitrogen from the air via a certain bacteria and making it available to it's host plant.
Okie, dokie!
Oh, Tapla ... need to build new screens and improve the way I attach the hardware cloth to the frames. Looked at your pics on post 7981475 from July 2010 but can't see that detail. How do you attach the hardware cloth? I've used large staples from a heavy duty staple gun and it works ok but wonder if there's a better method? Thanks,
Mary
That'd be this post: http://davesgarden.com/community/forums/p.php?pid=7981475
Mary - for the insect screen, I use plenty of 5/16" staples from an Ace brand staple gun, then tap them home with a hammer. I use furniture (upholstery) staples for the hardware cloth. I took pictures showing how I half-lapped the lumber and attached the screening, but I'll be darned if I can find them. Nasty weather here, I'll take some pics when it breaks.
Al
tapla, I have spent several days review past comments in this thread and the other related thread on intensive gardening in raised beds. What you are saying makes good sense to me and as stated in the other thread I have come up with a different approach to the mixes to be used in the composition and layering in the raised beds. The heat factor of the lower level of decomposing organics was purposeful in the sense that I am attempting to garden out of season so to speak. The covered raised beds are simply an attempt to garden eight months out of the year instead of four. The crops chosen are typical cool weather crops such as lettuce, spinach and cole crops. An early spring and late fall crop of each of these types of crops is all that I intend to do this season. If all goes well I may get aggressive and do something more exciting next spring.
GG, Tapla uses the word immobilized for my words, "tied-up". His sound more professional to me but go ahead. Anything that really helps people, I am for it. Cam
Well good luck to you, Morgan! ;-) I'm glad you found some value in my offerings. Cam deserves an 'attaboy' for all the helpful info, too!
Al
Mary,
I found some industrial steel shelving that was being thrown away.
I just drop my screens on top of that, so the (relatively fragile) scrrens don't droop or tear.
Sometimes I tie them down. A careful mechaic might use wire to tie them down permanentlyy.
Corey
Mraider,
I keep seeing the word "manure" in your plans. My theory is that enough manure (15:1 C:N) will overcome any temporary nitrogen deficit from the raw sawdust and wood chips.
And if not, a sprinkling of high-N fertilizer should overcome it.
And it's self-correcting after a season or two, especially if you add fertilize4r or compost each year.
The rock dust - clay - grated soil (if it is like the clay I'm used to) will be greatly softened by all the organic material. Your sand, sawdust, topsoil and wood chips ought to keep it from re-compacting. And diluting it so much with non-clay will help greatlky.
I like the idea of calling clay "rock dust". You could even say "colloidal rock dust". However, i think that most kinds of clay, if true "clay", do not some much PROVIDE mineral nutrients by slowly breaking down, as they provide a chemical BUFFERING, by adsorbing and slowly releasing any ions that float by them. Instead of washing right out of sand or spongy organics, ions from fertilizer or decomposing manure will cling to clay particles until the water around them becomes diluted, then the clay releases them to the water.
Like a bank account that soaks up money when you have excess, and then trickles it out as needed.
I think of "rock dust" as very finely crushed rock or powdered rock, in such fine particles that it is mostly surface area. It weathers faster that way, and acid rain or "humic acids" or earthworm intestinal juices or lichens or endomycorhizia have a maximum opportunity to strip nutrients off the surface of tiny rock grains.
I like the term "rock flour". As if one were making rock gravy or rock biscuits to feed to the soil.
Corey
I certainly appreciate all of your help in this matter. All your postings in the container gardening and intensive raised bed gardening have provided a wealth of information which I am still digesting. I consider myself fortunate to have a number of the components necessary to make up the components which go into making the growing media for these raised beds available for the taking. If the initial plan works I should be able to sustain these beds for a number of years with a lot less effort based on what I have read. So let’s just hope I get it right the first time. TYVM
morgan