By rights, the imperial estate isn't allowed to conscript corvée labor; corvée men are supposed to serve only public works of the state, like building roads and bridges, digging canals, shoring up riverbanks, or hauling provisions for the army and the like.
But if everything in this world really followed "by rights," the world wouldn't fall into chaos, dynasties wouldn't keep changing, and those in high positions wouldn't be replaced batch after batch.
Whether it was Bai Shan, Bai Erlang, or Manbao, most of what they knew of the world still came from books.
The books never mentioned that corvée laborers would also have to plow and harvest for the imperial estate, so all of them were surprised.
Especially since they even had to bring their own food to work on the imperial estate; that was going a bit too far. When serving corvée for the County Governmental Office or the prefectural office, at least they were given three meals a day, watery as they might be.
