In article ,
anthony123hopki wrote:

Hi

I am preparing my raised beds for some early spring sowing. I put in
some manure a few months ago. Over the last year or so the beds have
really settled down and so there is plenty of room to add more to them.


I was wondering if it is better to add pure compost or topsoil or a mix
of both. Does pure compost have all the nutrients a vegetable needs, and
do the nutrients last very long, or is topsoil longer lasting? Also,
what is a "soil improver"?

My soil is tending towards to clay side of things.

Thanks for any advice.

Look at
http://www.puyallup.wsu.edu/~Linda%2...ltural%20Myths
_files/Myths/Compost%20overdose.pdf for an overview to soil amendments.

The inorganic portion of your soil (85%-90%) is roughly, 20 - 30% clay,
30 - 50% silt, 30 - 50% sand. The organic content is 5 - 10%.

Clay is good for soil, as it retains water and plant nutients, but too
muck clay will prevent penetration of water into the soil.
http://www.toronto.ca/health/pesticides/pdf/gardening_soil.pdf
http://michiganorganic.msu.edu/Porta...20Crop%20Syste
ms.pdf
http://findarticles.com/p/articles/m...9936387/?tag=c
ontent;col1
http://www.finegardening.com/how-to/articles/improving-clay-soils.aspx
http://www.swcoloradohome.com/articles/gardening/greenthumb25.asp
http://www.remarc.com/craig/?p=261
http://attra.ncat.org/attra-pub/covercrop.html#organic

To break up clay soils, I'd recommend a cover crop of rye or buckwheat.
I have problems with daylight because I live on the north side of a hill
and I am just starting to get some full sunlight into my beds. Rye
improved my beds amazingly last year. This year I've sown rye and
buckwheat, earlier than last year, and the buckwheat is performing
better than the rye, so far.

I add chicken manure (18 lbs/100 sq.ft.), rock phosphate, charcoal, and
whatever else I intend to add to the beds, and then cover the cover
crops (cut or not) with newsprint two weeks before I'm ready to plant
(sometime in May), and mulch over the newsprint with alfalfa (lucerne).

This is "no dig" gardening.

Tillage of soil releases a flush of nutrients, which can give an
impressive initial boost to crop growth. But this surge of available
nutrients results mostly from the death of large numbers of soil
organisms, whose biomass decomposes rapidly into the soil. These
nutrients tend to be in soluble and volatile forms, and if not taken up
immediately by plant roots, are leached to groundwater or outgassed to
the atmosphere. In the meantime, life cycles of many soil species are
disrupted ‹ fungal threads are broken, and earthworm burrows are
destroyed ‹ and it can be some time before their populations recover. If
the next tillage occurs before they have done so, we have started a
cycle which degrades the health and diversity of the soil food web.
One of the worst effects of excess tillage is the loss of carbon bound
in the soil in the form of humus. Oxygen is necessary to soil life,
which is a major reason we work to improve aeration in soil through
creation of looser, more open ³pore structure.² Excessive exposure of
the soil to oxygen, however, as occurs in heavy tillage, leads to
oxidation of the carbon content and its loss to the atmosphere as carbon
dioxide (CO?). Not only is fertility ‹ which is so dependent on humus
content ‹ impaired, but high-tillage agriculture is a major, and
growing, cause of accumulation of CO?, a greenhouse gas, in the
atmosphere.
http://www.motherearthnews.com/Organ...1/How-To-Impro
ve-Soil.aspx

One cautionary note though, beware chemical fertilizers. This doesn't
come from ridged ideology but from the facts that numero-uno: chemical
fertilizers, used at suggested rates, kill off soil organisms, which
leads to less top soil, which leads to the use of more chemferts to
maintain production, and numero-two-o: the translocation of the nitrogen
to the plants now rapidly growing leaves (nitrogen rich, tender leaves)
makes them a target for garden insects.

Take advantage of your local library and read:

Teaming with Microbes: A Gardener's Guide to the Soil Food Web
Jeff Lowenfels and Wayne Lewis
http://www.amazon.com/Teaming-Microb.../dp/0881927775
/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1206815176&sr= 1-1

The Omnivore's Dilemma: A Natural History of Four Meals by Michael Pollan
http://www.amazon.com/Omnivores-Dile...ls/dp/01430385
83/ref=pd_bbs_1?ie=UTF8&s=books&qid=1206815576&sr=1-1
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