Tillage, n.
1. The operation, practice, or art of tilling or preparing land for seed, and keeping the ground in a proper state for the growth of crops.
2. A place tilled or cultivated; cultivated land.
Syn. -- Cultivation; culture; husbandry; farming; agriculture.
Shades of meaning
Fernald has no entry of its own for tillage; he lists it under agriculture.
Where he writes about it:
Tillage refers directly to the work bestowed upon the land, as plowing, manuring, etc.; cultivation refers especially to the processes that bring forward the crop; we speak of the tillage of the soil, the cultivation of corn; we also speak of land as in a state of cultivation, under cultivation, etc. — from agriculture