Gives farmland a range of textures depending on moisture level. Textures are just interpolations of the default "farmland.png" and "farmland_moist.png" textures. (In vanilla it's just farmland_moist.png for max hydration and farmland.png for everything else.)
Vanilla only uses the moisture levels 0 and 7, so you'll need another mod to actually use the other levels. Originally made to be used with Give Me Water Or Give Me Death, but that mod no longer needs this resource pack.