The average production of wheat in Canada is 2.37 tonnes per hectare[1]. This is 2 370 000 grams per hectare.

The energy content of flour is 1 440 000 Joules per 100 grams 1.

Assuming that milling wheat into flour has no energy cost then the energy yield is; 34 128 000 000 Joules/hectare.

1 adult male’s daily energy requirement is 10 500 000 Joules per day.

1 adult male’s yearly energy requirement is 3 832 500 000 Joules per year.

1 village of 30 adult males requires 114 975 000 000 Joules/year.

Therefore, if the village obtained all its biological energy needs from wheat then it needs 3.3 hectares of land devoted to wheat production. If this were to happen, each person would be responsible for 33 000 square metres of wheat.

The harvest expectations are however exaggerated. There is no cost for watering/irrigation, fertilizer, herbicide, or insecticide. Further, the above yield assumes a mechanized farm. The yield for a typical non-mechanized farm (eg India circa 1950s) was 500 kilograms per hectare. As such, the village would need to maintain 16 hectares and each villager would need look after 5 300 square metres.

Without the benefits of mechanization, each villager must look after at least 15 square metres of land each and every day. This leaves precious little time for research and development whether climate forecasting or designing fusion reactors.

[1] Agriculture Canada
[2] FAO