hau Heather,
Excellent question and you have gotten some good answers already. The really big question is; are these plants something that can not live there because of what you want to do in that space?
Chop and Drop is a great avenue that will build soil just as nature builds soil, by plants dying and rotting and coming back from the roots or starting over from seeds dropped.
Pulling up root and all means you are redistributing some minerals to the surface, just like what happens when a tree is blown over by wind.
Cutting the top of the plant and letting it rot while the root remains allows the top part to rot and the root to either survive and regrow or die, this depends on the nature of the plant.
Disturbance is not bad for soil, in fact it is the way Nature works to create soil. Many people seem to think that Nature does not Disturb soil, but in reality nature disturbs soil all the time.
Fires sweep through (disturbance), floods wash down hill (disturbance) Winds uproot
trees (disturbance) Volcanoes erupt (disturbance). You get the idea, nature makes her living by creating disturbances, then she starts to rebuild.
Trees blowing over or getting burnt up re-distribute minerals, bringing what was
underground to the surface where it can nurture new growth. Disturbance is how nature builds soil. Only humans seem to think they know better than nature.
Animals are also part of nature's method of disturbance, their hooves trample vegetation into the soil, they mow grasses and browse trees (raising the lower branches which can prevent diseases from spreading easily), they
poop and
pee to provide fertilizer to the ground.
All these are soil building on a grand scale, nature's scale.
What you first need to do is make the decision, do you want rather sterile conditions that require you to make additions every year? Or, do you want to just cut, let rot in place and plant through what is already doing the work of soil building for you?
Either is acceptable, however, one of the principles of the
permaculture ideology is to mimic nature, that is the best method for healing our earth mother.
To not follow the way nature works, we have to spend money or time or both trying to do what she does without our meddling ways. The traditional farmer takes the meddling ways to the extreme, the opposite of what we want to do.
Tilling mimics nature when a tree falls or even an entire portion of a forest is blown over. Tilling every year does not mimic nature, it is instead a state of constant disturbance, something which nature doesn't do.
No-till is a great method for traditional farmers, since it teaches them that they don't have to till the soil every time they want to plant a crop. That is where the idea of no-till came from, those of us teaching farmers how to get better crops with less expenditures of money.
No-till really isn't necessary for small plots of
land, but it doesn't mean you want to dig up your garden every time you plant either.
Tilling is disturbance that is done deliberately so we can let nature start over, with the idea of our own intentions being the dominating theme.
To mimic nature we first have to fully and objectively watch how nature works her magic and then we need to understand progression of species, which is the tool of reestablishment, it occurs with or without people being around.
Have fun, do as little work as needed to get to your end goals for food, and remember, nature was here long before us, and it will be here long after the last one of us is gone.
We just need to learn how to stay out of her way and not poison her anymore.
By just doing that, we can help her heal. If we want to help her heal and grow food for ourselves, then we only need to mimic her methods.
Redhawk