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When we use tillage the soil ecosystem is disturbed on a massive scale. Purdue's Dr.
Eileen Kladivko contrasted natural ecosystems with tilled systems and what we stand to lose
when soils are tilled.
If you think about natural ecosystems they don't have a tillage implement running through
them once a year or a couple times a year but nutrients get recycled and trees grow
or grasses grow and what's recycling the nutrients are the organisms and so part of what we are
saying with the no till system is that if you don't take an implement through there
and you allow the system to kind of comeback that there will be organisms that will do
that job for you, they do it differently obviously than a piece of metal would do it, but they
can be very effective and besides loosening the soil or making burrows they do some of
these other things like convert nutrients, recycle nutrients have pathways where roots
can grow and then those pathways stay there, if you think about a tillage implement any
root channel from last year in the top soil is going to be totally broken up by a tillage
implement the next year. You have a night crawler channel or even if you have a red
worm channel that is part of the red worm channel its there and the roots can follow
that and so you can have channel built upon channel, built upon channel, the night crawler
channel, maybe a root, maybe a cornuted, maybe a cover crop root will go down that and then
the next year another night crawler, and so and so it builds upon itself.
Will you explain to us why organic matter decomposes faster because of tillage?
A tillage operation does a couple things, number one is it opens up aggregates that
were otherwise protected so your opening up more surfaces for the bacteria to decompose
the organic material faster, that is probably the main reason, sometimes people say well
your putting oxygen in the soil, its not really so much that as by breaking up aggregates
you expose the organic matter in the soil to decomposition whereas when it's in an aggregated
state in the soil some of that is protected and the bacteria that decompose that organic
matter can't get to it.
So the tillage actually favors bacteria that would live in that environment. That's maybe
what causes the flush of carbon dioxide and nitrates into the soil as well I guess?
Oh yes, the flush of carbon dioxide is very much related to the tillage operation.