[guard-of-terra]

To even start to replace petroleum, hemp oil has to be very cheap. This means using optimal land for growing it - plains, well-lit, well-rained. Where it would compete with wheat and other food grown.

Trying to grow hemp (for hemp oil) on rough terrain won't work - far too expensive given the implications of manual labor.

[hackercomplex]

1. Hemp oil does not have to become cheaper than petrol in order to become widely used globally because consumer behavior is likely to change to accomodate it. What I mean is educated consumers are willing to pay more for the "green alternative" of their disposable plastic product because they recognize they will see that the extra value is created when the product does not create a destructive externality.

2. Wheat is not an ideal primary food crop in terms of nutrition for an advanced civilization that has the technology to scale distributed food production of much more nutritious plants. Instead we could scale out verical farming, aquaponics technology, permaculture, etc. Still I don't believe industrial hemp would effect large scale wheat production. I think that's a misnomer based on calculations centered around the idea of what it would take to replace petrol completely.

You can certainly grow hemp on flat terrain that is not optimal for food crops, but how much can be realistically harvested on truly rough terrain is debateable. It helps to remember that since you don't need insect repellent or petro-fertilizers it's signficantly easier to grow. I estimate that it could at least double the amount of land that can be used for productive farming in the US, and another thing is that hemp actually helps add nitrogen back into the soil.. in other words it's an excellent "cover crop". In addition it only needs to be rotated once every 70 years.