Farmers could use the water to water the crops
Farmers take or divert water from a river for irrigation purposes, and to water their crops.
There's not enough rain to water the crops. The farmers have to get the water that runs off the mountains to where the crops are.
The Aztec farmers watered their plants by waiting for rain to give them water.
no water to much sun
Rain
Each and everyone of them. It's hot and dry area, even the ones growing crops near watersources have to water their crops time to time.Although, if you want to nit-pick then I suppose the farmers that are currently in the military do not water crops.
4. How did ancient farmers use the water of the Indus river system to help grow crops?
They Can Use Groundwater
irrigation
they used cannals?
Earlier farmers watered their crops by wooden plows. This was back in the older days.