(You may also see this on the web page: https://www.capitalismlab.com/farm-extension)
When you find that your farm cannot produce enough food to meet the demand, previously you must build more farms to produce the same food. You can now simply expand your farm by building new farming tiles around it.
First enable the Farm Extension option on the Experimental DLC page of the New Game Settings menu.
You will see a new Farm Extension icon on your farm. Click on it to activate the Farm Extension mode.
Now drag an area around your farm to buy the land and build the new farming tiles.
The new farming tiles have been built and the capacity of all the units in your farm will increase as a result. Keep in mind that the monthly operating cost of your farm will rise accordingly.
By hovering over the Farming Extension icon, you can see how many new farming tiles have been added and how much farming capacity has been increased.
