[Garden] Our compost may be unusable

[gcmichal at envmail.uwaterloo.ca]

I just noticed an email in the stream mentioning that  layers of  
woodchips had been placed in the compost heap.  Sorry, but that means  
that the compost probably isn't worth using now, and in fact could  
seriously reduce soil nutrient levels if added to the garden.

I learned this the hard way.  We had a tree cut down in our yard and  
the tree removal firm used a chipper to reduce the twigs and small  
branches to coarse sawdust and small chips.  I thought this would be  
excellent compost for the garden and worked it into the soil a couple  
of weeks before spring planting.  I planted the garden and watched the  
seeds come up.  The plants sprouted very well -- and then stalled,  
didn't grow any more and started turning yellow.  I then took a  
sampling of the seedlings, rinsed the soil off the roots, and  
replanted them in a different part of the garden that had received no  
wood chips.  After just a couple of days those seedlings took off  
again and regained their health.  What had happened?  A proliferation  
of denitrifying bacteria had been stimulated by the presence of the  
wood chips and used up the available nitrogen in the soil, releasing  
it as gaseous nitrogen molecules. The seedlings made it okay on their  
seed reserves in the cotyledons, but quickly exhausted that and then  
had to rely on soil nitrogen.  That's when the trouble began. The  
garden was dead for the year - even adding fertilizer wouldn't help  
very much because the bacteria, still busily engaged in decomposing  
the wood, would "burn it up".

Aliciah's soil tests (although the figures were reported without some  
reference to accepted numerical standards for growing plants) came in  
as "low", which sounds like a situation that would be vulnerable to  
nitrogen depletion from mixing wood chips into it. Sounds like a new  
compost pile should be started and the one with chips in it just left  
alone to rot for a few years.

I did mention this earlier when I expressed my concerns about how much  
of the garden is now being given over to paths and the problems that  
overuse of wood chips can present.  I apologize if this is  
repetitious. I was over at the community garden at the Lutheran church  
on Willow street.  Paths there take only 5% of their total garden  
area.  When I last calculated ours, it was over 34% and may now be  
approaching 40%. In most community gardens it's 10-15%.

- Greg Michalenko

  Quoting Britton Jenner <britton.jenner at gmail.com>:

> Hey everyone, I volunteer with Food Not Bombs and we have lots of surplus,
> slightly rotten veggies that we don't want every saturday.  I told them that
> they could put them in the community garden compost, but if food services is
> also giving us compost maybe this wasn't a good idea.  Anyways, I only told
> them about it today, so if it was a bad idea someone tell me and I can
> rectify matters.
>
> Britton
>
> On Fri, May 29, 2009 at 2:32 PM, Paul Nijjar <paul_nijjar at yahoo.ca> wrote:
>
>> On Fri, May 29, 2009 at 05:41:08PM -0400, wendy michaud wrote:
>>
>> > Since this may influence your decision...  I finally got in touch
>> > with the appropriate person in Dining Services and they've agreed to
>> > give us stuff for compost!!  So I'll be bringing buckets of
>> > nutrient-rich goodness over to the garden every tuesday and
>> > thursday.
>>
>> That's excellent.
>>
>> >
>> > I'm happy to take care of that myself while I'm around, but I will
>> > be gone from June 13th 'till the 28th. So if someone can handle
>> > pick-ups that week let me know, otherwise there will just be a two
>> > week lull in rotting food excitement while I'm away.
>>
>> At what time do the pickups need to happen? Where do we do the
>> pickups?
>>
>> > Did we work out some sort of system for rotating the compost bins?
>> > Sorry, I haven't had a chance to do much gardening lately :(  If not
>> > maybe I can just find something to tie onto the bin for new stuff
>> > and rotate to the next bin when the first gets full?
>>
>> Unfortunately, now we have to make some
>> decisions. Two of our composters are filled with layers that include a
>> lot of woodchips. I am guessing that if we wait for those woodchips to
>> compost we are going to tie up those two composters for years (after
>> all, we put woodchips on paths precisely because they don't rot
>> quickly).
>>
>> So now we have the following choices:
>>
>>        0. Undo the layering work that was done.
>>
>>        1. Somehow build more composters (where?)
>>
>>        2. Restrict the amount of compost material we get from Food
>>        Services pretty drastically.
>>
>>        3. Something I am not thinking of.
>>
>> I definitely think that you should collect compost while you can,
>> though.
>>
>> - Paul
>>
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>