tilled land vs tilth

tilled land and tilth both are nouns.

Word	Noun	Adjective	Verb	Adverb
tilled land	Yes	No	No	No
tilth	Yes	No	No	No

As nouns, tilled land and tilth are synonyms defined as:

tilled land and tilth: arable land that is worked by plowing and sowing and raising crops

Other synonyms of tilled land include cultivated land, farmland, ploughland, plowland, tillage.

tilled land (noun)	tilth (noun)
arable land that is worked by plowing and sowing and raising crops	arable land that is worked by plowing and sowing and raising crops
	the state of aggregation of soil and its condition for supporting plant growth