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To highlight what I'm getting at: Behind my house is a field, small by modern standards; about the size of 10 football pitches. It gets ploughed by tractor & plough in about 1 hour or so, ditto for fertilizing & also seeding, later in the year, with a combine harvester the corn is separated from the straw which is baled.
The whole amount of man-hours is one man less than one day courtesy of diesel fuel.
If you go back to pre- oil & combustion engines, that same amount of food produced would, using horses, scythes & back-breaking labour , would have taken hundreds of hours. Multiply this on a country or world-wide scale & how are we going to do it - with electricity? & produced from what?