I built 3 small hugelkultur beds this year in my garden. I am looking to build one or two larger beds for next year. I work for a heavy equipment operator and have access to a bulldozer, excavator,backhoe, bobcat, etc., as well as a very experienced and conscientious operator. I have access to rotten and green logs, our company does "fire clearance" work that generates a lot of logs. I have established connections with some local tree services for chipped brush as well as a local horse training barn. I am located in the foothills of California. The site I am thinking is a pasture with a very gentle slope to the east, and good southern exposure.
I am open to any advice on layout or construction. I am currently picturing cutting a trench with the bulldozer then ripping the bottom of the trench, to aid in water infiltration. I am planning on setting the sod layer to the side. Then using the track-hoe fill the trench with logs up to maybe 6' above grade? Again using the track-hoe place the sod on top of the log pile and then dress the top with the fill dirt, and composted horse manure. I was thinking about dressing the mounds with wood chips, I have access to about 200 yards.
The logs I have access to are primarily Ponderosa Pine, Live Oak, Black Oak, White Fir, and some cedar. All the logs are in a very large pile and some are rotted to the point of no identification. All the logs are in 6' lengths for legal transport. I have been able to I.D. and set aside all the cedar so far.
My primary questions are. How deep should the trench be? How deep should it be ripped? I have 18" and 3' rippers available. Should I do any amendments to the trench before the logs go in? Should I orient the bed East to West or place it on contour? What might be the ideal length and height of the beds? I am thinking fifty or so feet long and six feet tall.
Thanks for any help or advice,