If tilling is so bad for soil life, then what is the consensus for using pigs and chickens to till areas before growing?
Do they till differently to a rotovator? Is it ok since they are manuring the soil? Is it really a question of animal pressure and not having animals so densely?
I like the idea of both having pigs but also i like the idea of no till so was wondering what your opinions are?
I think some specificity is required. First off, in cases of rehabilitating soil where the life is poor or non-existent, tilling may be required to break up hardpan, mix needed amendments into soil to give soil life something on which to thrive, or to ameliorate hydrological conditions.
Secondly, what is generally thought of to be worst about tilling is the frequency with which it is done in maximum tillage systems, where the soil structure isn't only being inverted, but chopped up and broken down to particulates so small that it can be picked up by the wind.
I think that pig and chicken tillage is automatically better because there's no soil inversion, not on the scale of a plow, anyways, and no topsoil blowing away with the evening breeze.
I think that animal tillage can be way more tuned in to the needs of the soil and the farmer than can the rotovator, as you can choose the type of seed, the spacing, and the size at harvest of the tubers, say, to guide how much disturbance the pigs cause. The chickens will literally clean as much of the exposed seed bank as they can following the pigs, meaning you get to tune your pasture or growing bed area more to your needs, to say nothing of the livestock parasites they will eat up as protein if the chickens follow an appropriate number of days after.
And all that manure can't be overlooked. Think of all that crap you don't have to clean out of somewhere to spread out somewhere else.
Our own Dr. Redhawk has a number of threads in this wiki touching on this very topic. I think on the whole the consensus is that an appropriate level of plowing can be justified if the system it helps create is healthier than what preceeded it, though it is complicated and everyone seems to see it in different ways.
Great question, though. I look forward to hearing others' opinions.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Nature uses animals to cause some forms of disruption such as trampling and rooting this tends to be localized instead of an "all over" disruption.
Nature also uses wind, water and fire to create disruptions, wind blows down trees, the root system leaves a pocket of freshly mixed soil horizons, it will also move exposed soils (dust storms).
Water erodes already laid down soils and redeposit the material at the lowest point and where the water slows down.
Fire burns off (exposes) soils to the wind and water, some seeds require fire to be able to germinate.
Tilling tends to be far more "large scale" disruption than anything nature does, this is why it can be devastating to soil life and soil health.
Tilling however can be judiciously done and when it is performed this way, it can actually be a good thing for the soil.
Tilling can break up compaction layers, adding needed air and water channels, it can blend horizons, allowing for more topsoil to be created via the microbiome.
As the tilling is done, improvements to the soil in the form of amendments such as compost or other organic materials are being put into the soil below the surface level.
However, turning over huge expanses of soil exposes those microorganisms living in the "treated" depth to UV light and UV light is deadly to those organisms, hence they die from sun burn.
This means that every time you till soil, you will need to replenish that soil with the missing microorganisms (since you killed them off).
The trick is to be aware of what your soil needs help with and which method of giving that help is the best, at that time.
One time tilling is a very good method of raising the humus levels of soil and it can be used to break up compaction layers at the same time.
This type of tilling is done in a single pass, then the soil is planted so the soil will be covered as soon as possible.
The trick to using animals is to keep them moving along (think predator pressure keeping a herd moving from one spot to another to another to another).
Many grass lands are right now being brought back to life by using large herds of cattle and moving them around three times a day, this mimics how a herd would move with a pack of wolves or a mountain lion stalking them.
The result is the grasses are eaten down to around 4" tall, manure is deposited and the soil is trampled, urine is deposited and the herd moves on to the next spot all day, every day.