Pavel Kucherov: September (1953)
Pavel Markov: Morning on the Collective Farm
S. F. Ivannikova: Saturday Work
Tatyana Yablonskaya: Sacking Grain (1949)
Valentin Bogdanov: Shearing Sheep (ca. 1950)
Vladimir Zajarkin: Resting from Work
[I guess technically this isn't a painting about farm work]
Vsevolod Petrov-Maslakov: Lunch in the Field
Vyacheslav Andreevich Fedorov: The Rye is Almost Ready (1955)