A quick and easy way to update multiple crops is to use the multi-edit function.
Please Note - When selecting multiple fields, all fields must have the same crop type.
To do this, select Crops and then click Multi-Select:
Select the crops required by clicking the tiles (once you select one, you can press Select All and any crops with the same type will be selected) and then click on Edit Selected Crops:
In the pop-up, update all the details you require and click Save & Close:
All details will be updated across the selected crops.