A farmer should only really roll a field no later than March as the ground gets too hard in april to flatten out, also you won't destroy any ground nesting birds nests in March. Normally as a rule of thumb the second week in March is dry enough to roll.
Heavy rolling is used to press down muck flat so it won't get into a forage crop, to press down stones that could damage a mower and to flatten down any mole hills or soil in general that could also get into a forage crop and kill live stock.
Rolling can make grass tiller which in theory should produce more grass. However heavy rolling can knock grasses growth back for a week or so.
Having said that some farmers roll regardless as it looks good and their farther used to do it.
farmers used the shaduf to irrigate their fields :):) its true
They used levee canals to bring water to their fields.
irrigation
through the system of irrigation
Since the fields were filled with water the farmers word for the king. Instead of working in the fields they helped work on the temples and pyramids.
Farmers pumping river water and spraying the water onto their fields of growing crops is known as crop irrigation.
Irrigation.
irrigation
irrigation
farmers leave their fields flooded with water as water has high specific heat and can stop the veins of the crops from bursting. -Anay Vakil
Farmers take or divert water from a river for irrigation purposes, and to water their crops.
from water researves irrigation