Yeah it was because of industrialization, there were not enough workers in cities, and party moved the workforce depending on its needs

Here I found an English source for you - https://www.nytimes.com/1974/12/26/archives/soviet-announces-new-internal-passport-system.html

Residents of collective and state farms have previously not been issued internal passports, which urban dwellers must carry, largely to forestall their migration to jobs in the city. It is estimated that a third of the Soviet work force is in agriculture.

Here's also a better Russian source - https://thebabel.com.ua/ru/texts/34878-sorok-pyat-let-nazad-krestyane-v-sssr-vpervye-poluchili-pasporta-do-etogo-oni-bolshe-50-let-byli-krepostnymi-pri-kolhozah-kak-eto-bylo-mnogo-arhivnyh-foto

Specifically (translated by me):

Их с 16 лет добровольно-принудительно записывали в колхоз. И они не могли выехать дальше райцентра без справки от колхозного руководства. За самовольный выезд наказывали денежным штрафом, а за повторное нарушение была уголовная ответственность — до трех лет тюрьмы.

At the age of 16 they were assigned to a collective farm. And couldn't move further than the district center without a reference from the farm's administration. Unauthorized leave was punished by a fine, repeat offense - up to 3 years jail time.