A field can grow a range of different crops and while the selected crop can be changed at any stage, only one crop can be grown at a time. Certain crops can only be harvested during certain seasons.
Adding scarecrows to your fields will prevent damage by birds and allow crops to grow quicker.
Placing a beehive in your field will allow you to produce honey and increase crop growth rate.
Keep the rodents out of your supplies.
Comfortable Working Conditions
Invest in a nicer working environment for your workers. Adding more workers to a single production will become much more efficient.
A dog will guard your workers and crops from foxes.