Re: Double-digging

At 09:30 PM 7/10/97 -0600, you wrote:
>dear Donald
>I recently saw a TV program which dealt with your concerns.  It seems
that, >according to this individual who is involved in total
>organic gardening, that double digging is in fact detrimental to the soil.
>He cites the fact that the micro-organisms in the initial sub-soil is far
>different from those in the deeper layers.  The plants
>require the organisms in the sub soil to thrive and mixing the soil
>substructure, by double digging, dilutes the micro-organisms in
>the topsoil and so delay or set back the plants.
>He cited the fact that farmers now do not plow their fields as deeply and
now  >harrow them.  This method does not dig into the
>soil as deeply and so has less disruption on the micro-organisms in the
top->soil.  
>I am not a farmer so I can not vouch for this.
>Frank for
>glmichaelis@man.net

Frank,

I believe that your information is probably accurate for in some of its
assumptions.  I work for the University of Georgia and once attended a
seminar which Dr. Eugene Odum (a.k.a., The Father of Modern Ecology)
presented on sustainable agriculture (the fancy terminology for not tilling
your farm fields).  There is good agricultural science which suggests that
repeated tilling and  high usage of inorganic fertilizers (mostly nitrogen)
will ruin the structure and affect the long term productivity of farmland.  

Sustainable agriculture theory combines minimal tilling with cover cropping
to actually improve topsoil and subsoil structure and maintain a constant
level of soil productivity (albeit slightly lower than those 3 or so good
years of yield with traditional U.S. farm practices).

I'm not sure how this would apply to small scale iris farming or your
backyard perennial border.  Many times your average home gardener has to
contend with varying degrees of topsoil vs. subsoil layers.  For instance,
my home is less than 10 years old and I'm still digging up bricks and
shingles from when the home was built.  I suspect that the subsoil and
topsoil were inverted in places close to the house (exactly where I want
flowers) during its construction.  Also there was probably a good deal of
compaction of the variously mixed soil layers from the use of heavy
equipment.  When one is up  against this type of soil (concrete and sand),
double digging to incorporate lots of organic matter can go a long way to
improving the fitness of the soil for growing beautiful perennials and
flowers.  

Of course, I rarely have the strength and stamina to double dig an area
repeatedly each year.:) I double dig new beds, mainly to improve drainage,
incorporate organic matter, and reduce compaction of the topsoil. By
feeding my soil as much organic matter as possible, I am able to sustain
growth in a flowerbed indefinitely without feeling the need to till or
double dig repeatedly.

Sorry if I bored anyone with the long message.  We will now return to our
regularly scheduled programming already in progress...

ZZZAPPP goes the T.V. 

<Poorly written, but distressing soap opera music blares>

"What? You say you're pregnant!!?" said the mom iris to the daughter iris.
"I told you to stay away from that promiscuous I. versicolor. You know how
the people in this small town feel about interspecies crosses!" scolded
mother I. virginica.

-Donald (with a twisted sense of humor)



Donald Mosser
Member of AIS, HIPS, SIGNA, SSI, SLI, SPCNI, and IRIS-L
dmosser@southconn.com
http://www.geocities.com/rainforest/5570

North Augusta, South Carolina, USA
On the South Carolina and Georgia Border
USDA Zone 7b-8
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index