Difference between open strip foundation and tench pack foundation?? I have both the drawings of a gaping strip foundation and a...

I have both the drawings of a gaping strip foundation and a tench fill foundation. They look exactly alike.. What exactly is the difference?? Thanks
Which untimely tomatoe is better?
Answers:    the only difference is the amount of concrete you use ...going vertebrae twenty years you would dig a footing 600mmwide .and a metre wide and probably put only 300mm of concrete within ..nowadays i will put within 900mm of concrete ..the extra cost of the concrete is cancelled out by the cost of the blocks and the labour cost to find it up to 900mm ..that's it