Complex sentence: The Spanish conquistadors also utilized the same form of labor system in supplying the workforce they needed for the silver mines, the basis of their economy in the colonial period, absorbing the concept of "mit'a" to suit their own needs.
Split into simpler sentences: The Spanish conquistadors also utilized the same labor system to supply the workforce they needed for the silver mines, which was the basis of their economy in the colonial period. The conquistadors used the concept of "mit'a" to suit their own needs.