Botulinum toxins are the most lethal toxins known. For type A toxin, the toxic dose is estimated at 0.001 mcg/kg (Franz 1997); the lethal dose for a 70-kg person by the oral route is estimated at 70 mcg, by the inhalational route 0.80 to 0.90 mcg, and by the intravenous route 0.09 to 0.15 mcg (Sobel 2005).
1 hectare = 2.47105381 acres. .07 hectare= .17 acres per person. about 7500 square feet per person. While this figure produces a result of around 5-6 people per acre, there are plenty of caveats to consider. If the soil is not ideal, increase the land. If the growing season is short, increase the land.
There are 16 ounces in a pound, so about 10 pounds of meat would be necessary to feed 20 people. According to the Food Network, when planning a barbecue or dinner party, there should be about 6 to 8 ounces of meat allocated per adult. Know More.