Earth

I do not understand your sentence.

which part?Does it make sense if I substitute 'land' for 'earth'?

You cannot replace land with earth here. The Earth is the planet we live on. Earth means soil, the stuff we plant things in.
Villagers walks is unclear also.

They own lands, don't they?
Do farmers also own easrth and it made them powerful?

They own the land, and by extension the earth (soil) on the land, and the plants growing on the land, but we say they are rich because they own so much land. We don't say they are rich because they own so much earth. Even if they were buying and selling the earth off the land we would actually say they have a lot of topsoil or fill-dirt etc., and not that they have a lot of earth. When we talk abo

Blue JayYou cannot replace land with earth here. The Earth is the planet we live on. Earth means soil, the stuff we plant things in.Villagers walks is unclear also.

does 'villagers walks of life' make more sense?
I want to emphasize that villagege had a king of social stratification.

soheil1does 'villagers walks of life' make more sense?

It still would not make much sense in "Land was an income source for the villagers walks of life"..

Yes, the villager's walks of life would make it somewhat clearer (note the apostrophe).
Walk of life usually means profession or career. It can mean social class. However, it is not usually used to mean social class when talking about specific individual classes. in other words, we might say Very rich people enjoy polo, but people in other walks of life enjoy soccer mo

How about this: Land was considered one of the main sources of income for the powerful Qajar class, and also was an income source for the ordinary villagers.

She insists of making it clear that they form a class, a walk of life

Blue JayLand was considered one of the main sources of income for the powerful Qajar class, and also was an income source for the ordinary villagers.

That makes sense.