Market Farming

[Alex McGregor <waldenfarm AT sprintmail.com>]

To all who asked,

I haven't forgotten about this.  I'll be sending what info I have as I'm able.

There were a bunch of questions, both on the list and personal emails, so I'll
be answering them in sections.  Please keep in mind that all we do is
interconnected, but we have to talk about them one at a time.

The questions fell into these areas: cold composting, adding compost (organic
matter) to the soil surface, tillage, cover crops and incorporation,
applications of hand labor Biointensive methods to tractor farming, and 
planting
patterns for machine cultivation.  I'll start with composting.

Preface- Biointensive methods, as I learned them from Steve Rioch, are based 
on
scientific knowledge of soils, plant life and their
interactions/interdependencies.  It's not a set system, applicable anywhere 
for
any crop.  Jeavons is an experience based gardener who tends to promote an
"orthodox" system- "do as I have done."  We both (Steve & I) think and teach
that gaining an understanding of the biochemical processes of life and their
connections allows someone to make management decisions that will lead to
success.  I don't make many specific recommendations unless I know a lot about
specific soil, climate and crops.  And I take the approach that the grower 
knows
more about these through experience than I do.  But I will try to impart some 
of
the information about these systems and some possible applications.  Also, 
Steve
& I do some things differently and agree that circumstances dictate some
methods, as long as we don't have a detrimental effect on the biology.

Someone mentioned that they don't have time to "hot" compost.  This is true in
most medium to large operations.  Hot composting requires having the different
kinds of material (high C & high N) in large quantities at the same time, a 
high
skill level and the time to manage the biological process through turning
(aeration) and moisture management.  This is fairly easy on a small scale but
next to impossible on a large scale.  And this is the type of composting most
widely touted.  (Reason later on.)

One alternative is to adopt the Biodynamic approach of building layered piles 
as
material is available and adding preps.  This is a "compromise" between hot &
cold.  There's less time spent managing and it takes longer for the material 
to
get broken down.

"Cold" composting is really a different animal from "hot," not just a passive
way of composting.  A true cold compost pile is put together to promote fungal
decomposition of high carbon (low nitrogen) material that's high in lignin and
cellulose, like sawdust, chips or cornstalks.  It's called cold because the
fungal metabolism of the material produces lower temperatures- ideally, 10
degrees F above ambient air temperature.  (There is some bacterial activity, 
but
fungi dominate.)

Cold composting requires less skill, more time (average one year) and less
management.  The main management is in keeping the material moist.  This is 
more
suited to a large operation that may have lots of on farm, high C (low N)
material available and not much time for management.

Now for the reason why we hear more about "hot" composting.  Our (farmers
throughout time) have observed that most annual plants do better when finished
compost from hot piles is added to the soil.  This is because it's a bacterial
dominated process- bacteria thrive in the aerated, C:N ratio of a hot pile.
(The "heat" is produced by the metabolism of the bacteria- high heat means 
high
metabolic rates, means material is broken down faster.)

When we add the finished compost to our soils, we're doing 2 things: 1. adding
food for the soil life, which thrives and produces nutrients for the plants 
and
2. inoculates the soil with a wide variety of life forms.  Since most annual
crops thrive in a bacterially dominated soil ecosystem, we're selecting for 
this
(and by using tillage, more on that later) by hot adding the products of hot
composting.

By the way, I don't use any manure in my hot piles because we don't have
animals.  We're surrounded by subdivisions and were annexed into a town that
doesn't allow "farm" animals (though I've thought of getting a goat, naming it
Muffy and teaching it to fetch).  And hauling manure is expensive and time
consuming- and what's available is from horses that get wormed regularly.

Back to hot compost- The finished product is relatively low in N, since N is
reduced to volatiles and solubles during composting.  Both hot and cold have 
low
N levels, so why do plants grown in soil not have an N deficiency?  Because a
soil ecosystem includes life forms that convert N in the soil air to plant
available N (nitrates in bacterially dominated soils and ammonium in fungally
dominated).  So, we're feeding the soil life and introducing more types of 
life,
which then start and continue the N cycles in the soil, resulting in N
absorption by plants.

Why choose between hot or cold compost?  Primarily for the specific crop.  
Since
hot composting is predominately a bacterially dominated process, it's good for
soil systems where we grow annuals- most food crops.  Since cold composting 
is a
fungally dominated system, it's good for perennials like vine, brambles, etc.

In fertile soils, those with adequate organic matter to support a diversified
soil ecosystem, all we need to do is maintain the organic matter to keep the
system going.  In poor soils that have low OM levels and a limited soil
ecosystem, we need to aerate the soil through tillage (more on tillage in a
later post) and bring the OM level up to the optimum for the soil climate and
farming applications.  Raising OM levels can be done through composting and
adding to soil, sheet composting (in situ) and cover crops.  Introduction of a
wide variety of life forms to the soil ecosystem can be done by adding 
compost,
BD preps, aerobic compost tea and some ways I don't know about.

I have had good success using cold compost in soil for vegetables.   (I have 
the
tree trimmers dump chips and let them rot over a year or so.  I mix this with
the hot compost.  An apprentice named this "Harvest Blend.")  I started mixing
this with I'm assuming this is because the end product will feed either and 
the
dominant life forms in the compost are overwhelmed and suppressed by the
dominants.  For a poor soil where I had cold compost, I would add the compost
AND inoculate the soil using one of the methods mentioned above.

Something to keep in mind is that rebuilding soil takes 3-5 years.  We're
managing biological systems and they take some time to diversify and balance.
And it takes time to get the "food" for these build up.

So, until next time, Adios Amoebas.

Alex McGregor
Walden Farm