Thanks for posting this Anderwood. I did have some trouble listening--my speakers have decided to make every audio presentation sound like bugs bunny. And I was thinking with respect to Dr. Ingham's video and discussion of soil vs dirt; just as my speakers are obscuring information and spitting out "noise" so do we have agricultural practices that obscure the natural structure of soil and turn it into dirt. This has had a profound effect on the structure and variety of plants that can be grown on the surface of the earth.
As professional archaeologists, this is what we do: turn soil into dirt. With pride we claim to be "dirt" archaeologists. But ethically we are constrained to document the information in the structure of the soil that we have obscured. [Every excavation has a "float column" reserved to recover the pollen present at every stratigraphic level. From that pollen, we can generate the plants characteristic of that particular context]. I remember well a 30 ft deep soil profile on the banks of the Tombigbee River here in west Alabama. The time line of that profile spanned from the present (the site was then in a pasture grazed by holsteins) to a paleo occupation some 10,000 years ago. We wound up excavating the activities of a palisaded chiefdom village @ about 1,000 A.D. Soil has structure that can be read by archaeologists. And that structure can also be read by plants--if it is not destroyed. And the practice of modern agriculture has been very destructive. Routinely in archaeology we discard the upper 20 to 30 cm of a site--the plowzone. The information has been destroyed by cultivation and it is of no value archaeologically. And it is not of much use for growing plants either after the soil structure has been destroyed. Years ago I wrote an article which considers how much of the earth's surface has been affected by cultivation. [The same Dave who founded All Things Plants.]
Dr. Ingham's discussion takes me back to the content of that article and leads me to review Fukuoka's work which was instrumental in founding the concept of permaculture. Soil is information--it is in the structure. And to grow plants that structure has to somehow be rebuilt.
