When to know it's worth to start with agriculture?

Question

Based on survival series, films etc. most of the people stranded on a lonely island (not necessarily restricted to this situation of course) over a long period start with agriculture at some point. While I understand that it gives you great benefits, it also consumes resources (water, energy etc.).

When do I know that the benefits outweigh the "waste" of resource (my daily routine is that stable, that it can handle the additional expense), so that I should start with agriculture? Which precedence does it have (like "Don't start with agriculture before you haven't ...")?

Answer 1

Assuming it is not an end of the world scenario, the answer is never start agriculture.

If you are not on an island;

• A traveling hunter/gather in a location that will support agriculture is going to be able to travel to civilization faster then any crop would come in.

• If the location will not support agriculture, you need to move to someplace that will, which puts you in the scenario above.

If you are on an island;

• Ecosystems are delicate, clearing land is going to disrupt the native ground cover, likely ending in the destruction of existing food sources. I doubt there is an island on earth that has an area suitable for farming, that would go longer without visitors then it would take for a crop to come to harvest.

• Farming takes tools, you have to make those tools. If you can make the tools to farm, you might as well make navigation implements and a boat.

Related What Navigation Aids can I make on an island with only a knife?

When harvesting hunter/gather don't kill off the food supply. You or another being is going to want it later.

• Leave a couple of those wild onions.
• Don't strip all the leaves off of the only edible plant.
• Don't kill nursing mothers, or any female animals at all if you can tell the gender.
• If you eat something with seeds, bury the seeds in a similar location, either after consuming them or instead of eating them ;)
• Most plants have developed so that being consumed leads to their improved survival, i.e. Fruit has seeds so that animals will carry those seeds to new locations after eating them.