impoverish

verb (used with object)

to reduce to poverty: a country impoverished by war.
to make poor in quality, productiveness, etc.; exhaust the strength or richness of: Bad farming practices impoverished the soil.

verb (tr)

to make poor or diminish the quality ofto impoverish society by cutting the grant to the arts
to deprive (soil, etc) of fertility

early 15c., empoverischen, from Old French empoveriss-, stem of empoverir, from em- + povre “poor” (see poor). Related: Impoverished; impoverishing.