> I have been observing the discussion on soil quality and would like
> to add a query. An issue which has been taken up with fervor by my
> colleagues in soil science has been the notion that potential for
> nitrate contamination of groundwater is **reduced** by using chemical
> rather than organic sources of N.
>
> The logic presented is that organic matter mineralizes in
> ways/rates/timing which a) is not controllable, and b) is not easily
> predictable, and hence, c) has the potential to continue to pump out
> labile N long after the crop has been harvested. On this basis, they
> discount the merit of long-held organic farming wisdom, namely, "feed
> the soil" as a source of immobilized and slowly released mineralized
> nutrients to feed the crop. The next dimension to this logic is that
> perennial forages, which enhance soil OM, are hazardous to the
> environment because when they are plowed under, they mineralize and
> release copious amounts of N - with again, the potential to pollute.
I 'm just a simple farmer and so I can only give my ideas and I'm open to
learning. I myself don't use a lot of compost and when I did I was sure
it was well composted . I use lots in the start but it had to not be
at all hot. Also I use little now I just let the weed and crop residue
lay on top of the soil like a mulch. I cut the weeds with a ciclebar
mower so the weeds just lay down like a mulch. I let the earth worms and
microbs turn it into humus . I think there is little chance THAT organic
matter is hurting anything. I feel thats feeding the soil and sure the N
is still there long after the crop because the crop only take what it
needs it no way hurts the ground water >
> In response, I can only agree with their logic **if** one continues
> to crop in conventional ways - with the land bare or under dead
> stubble for 7- 10 months of the year. However, a great deal of the
> rationale behind organic field crop agriculture is to keep the land
> covered with a live - and predominantly, growing - crop year-around.
> This practice, in addition to supplying a sink for labile nutrients,
> also keeps the soil colder longer and enhances the synchrony between
> such T-sensitive processes as microbially-based mineralization and
> plant-based uptake.
I think you get more microbially-based mineralization and plant-base
uptake being organic. thats the whole idea. Organic stimulates the
production of Phytamins in the soil for the plants. I understand that
Phytamins are an important part of the soil solution,they are created by
the soil life to control plant growth and vigor. I feel a good
sustainable farmer adds little from outside (chemical or organic). The
farmers around me that use 16/16/16 have way more N in leaf samples than
me and the ag. agent said cut down on the N ferterlizer. The trees don't
need that much N yet it seem to me being organic the trees only take up
what they need and I never have the trouble your talking about. At least
I don't think I do. My ideal of good soil is one that is self renewing
one where if you drop a seed on the grown it grows. it gets better every
year more alive . Improve tilth soil that supplies the plants with
essential biologically active nutrients. The plants would require less
water improved water penetration and moisture holding capacities.high
seed germination rates and extensive root system formation. Non-polluting
and ecologically sound,balance in soil metabolism with a high production
of stable humus are some things to shot for.
interested in the comments of SANETers on these issues,
> particularly as they pertain to the definition of soil quality, and
> ultimately, the attributes of the "ideal" soil that we should be
> shooting for. Ann
>
> ACLARK@crop.uoguelph.ca
> Dr. E. Ann Clark
> Associate Professor
> Crop Science
> University of Guelph
> Guelph, ON N1G 2W1
> Phone: 519-824-4120 Ext. 2508
> FAX: 519 763-8933
>
Sal Schettino,Organic Farmer,don't panic eat organic,sals@rain.org
or check out my homepage: http://www.rain.org/~sals/my.html