Farming-out work

A conversation at work, referring to subcontracting some aspect of our office work - the tedious mapping - (that was tedious and exhaustive, preventing our more analytical tasks), I said maybe we should farm-out these project elements or work---
does anyone know the origin of this phrase ?

The dictionary does;
Main Entry: farm out
Function: transitive verb
Date: 1607
1 : to turn over (as a job) for performance by another usually under contract