[Arid_gardener] Re: Sheet Composting

[Olin Miller]

Re.:  Current thread about compost

Most of us make compost by the process placing vegetative material or
herbivorous animal manure or a mixture thereof in a pile or container and
allowing it to rot.  There are various techniques to speed up the process.
Sheet composting is the process of spreading the material over the soil and
sowing a nitrogen-fixing legume (a so-called green manure) which is then
worked into the soil to offset the temporary nitrogen depletion that results
from the decaying process.  Some 20-30 years ago, sheet composting was
heavily promoted by the Gardenway Manufacturing Company, as a way to promote
use and sales of their TroyBilt Horse rototillers.  According to Gardenway,
fewer nutrients were lost than with the pile method and nutrients are
released slowly with less nitrogen loss due to vaporization.  In our desert
climate, the method doesn't work very well because the material doesn't
rot - it just lies on the ground and attracts pests.

Olin Miller, Master Gardener Volunteer
U of A Cooperative Extension, Maricopa County AZ
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----- Original Message ----- From: "Dick" <rkgross3 at cox.net>
Sent: Sunday, August 19, 2007 10:35 AM

> As I understand the process, Dianne, vegetative debris (anything organic)
> is not compost until it has been eaten, digested and excreted as frass, I
> think it is called, from the gut of soil organisms. The excretesd waste
> represents many complex hydrocarbon compounds that have been broken down
> into chemical forms that can be adsorbed by feeder roots and used by the
> new plant to build new cells.
>
> If you blend unfinished vegetative waste into the soil, the avaliable
> nitrogen is gobbled up by the feeding organisms leaving little to mourish
> feeder roots to build new cells for plant structures like foliage, flowers
> and fruit.
>
> One can make up the difference by adding more 33-0-0 Ammonium Nitrate or
> 21-0-0 Ammonium sulphate but if too much nitrogen is added, you can end up
> with dead plants or with a lot of foliar growth but, feeling fat and
> sassy, the organism does not concieve a need to reproduce, so most of its
> energy is used to make leaves instead of flowers, seed and fruit.
>  ...