To get the Harvest X hectares trophies, you have to harvest the crops in your own land. Go to the shop and buy a Harvestor, note that it only works with a suitable header. Make sure the header you bought is suitable for harvesting the crop type of your farm, for example, Wheat/Barley uses different header then Corn/Sunflowers, and some crops uses specific Harvestor, like sugar beet/cotton/sugar cane. Attach your header to the harvestor you bought at the shop, drive to your farm, unfold your harvestor, unfold and lower your header, turn the harvestor on and drive in to your farmland to harvest. Once the harvestor is full, drive a tractor/truck/car with a trailer attached next to the harvestor and press [pipe out] from the harvestor, now when your trailer is right below the pipe end the harvestor will start dumping the crops into the trailer, now you can drive the trailer to a silo to store it or a place to sell it.To check how much land you harvested, press option and scroll to the statics page, note that you don't need to harvest all the hectares in one session. Note that doing contract does not count towards the total hectares. Note that you can hire workers, it counts.