Healthy or fertile soil?

Do we mix up the terms healthy soil and fertile soil?

My contention is that that a healthy soil is one which has a diversity of species which are living in balance with each other.  An analogy would be when a pond eventually becomes crystal clear because everything is in balance.  The problem with creating a healthy soil is that it cannot be worked on and it cannot be cropped.  To do this would upset the balance by removing recycling nutrients, breaking symbiotic relationships and killing soil fauna and flora.

Having said that, humans are part of the natural world and taking vegetation to eat in a permaculture kind of way must be fairly sustainable just as long as we return our waste to the environment. 
As we have seen from modern scientific agriculture, we can have a fertile soil which is very poor in biodiversity and is very unlikely to be sustainable.

The trick is to be able to have a healthy soil which has a diverse population of organisms while also being very fertile providing crops to harvest. 

Although this is more likely to happen if we use organic methods, growing food is not a process that is conducive to producing a healthy soil.  Even in organic gardening we have to alter soil conditions to suppress pest and disease organisms dominating the soil population.  Do we just accept that we have to do this to produce food for ourselves or do we work much harder to find methods of growing that do not involve major disturbance to the soil. 

I would suggest that producing small areas of very intensive fertile soil, which is as healthy as possible, is the way to garden in the future.  I am not really arguing for no dig methods because they are not really viable in a proper cropping rotation.  This method is fine for handkerchief sized raised beds but not for allotment sized beds, although it does have its place even here.  I just think that a “no dig method” will not achieve a healthy soil when the next rotated crop involves digging to crop it – as with potatoes.   Taking crops out of the soil must affect microorganisms because we are removing both rhizosphere habitat and food. 

Also, to achieve a high fertility in organic systems large amounts of organic matter have to be added to the soil.  This can be achieved by mulches but I would suggest that it is quicker and more effective to dig the organic matter, such as manures and composts, into the soil. 

If we are going to use the hugelkulture where brushwood is laid on top of the soil and covered with top soil to produce a raised bed or my Montezuma method where logs and branches are buried deep in the soil or even the chinampa method of the native South Americans, we will be breaking the soil and affecting the diversity and balance of organisms within the soil. 

All these methods of introducing large quantities of organic carbon into the soil together with the traditional composts and manures  may well alter the dynamics of the soil balance.  I would like to believe that there is an increase in the diversity and interrelationships of organisms within the soil when organic matter is introduced.  Realistically, there must be a cost to breaking the soil to crop it and this is reflected in the destruction of soil communities when digging and cultivation occur.

The ancient South Americans produced a very fertile black soil now called Terra preta by adding mulches of inoculated charcoal.  These soils are even now sometimes metres deep.  The literature suggests that Terra preta did have a unique population of micro organisms.  Could these soils be called both healthy and fertile?  The charcoal may provide habitats for useful micro organisms that otherwise would be preyed on excessively by the soil predators.  If this is so then charcoal will increase the diversity and possibly the health of the soil.  
Both increasing the health and the fertility of the soil in a balanced way is extremely difficult but if ancient peoples found a way of doing it, it must be possible.  

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