How did sharecropping create a cycle of poverty for african americans in the south

Sharecropping is a practice where a tenant gain the right to cultivate the land in return for a share of their crops produced on that portion of land. It is an unfair practice because frequent changes in crop prices, possibility of unfair weather or pests destroying the crop, and tendency of landowners to apply pressure on the sharecroppers by threatening not to renew the lease at the end of the growing season.  African Americans, freed but penniless, often found themselves finding work as sharecroppers and in competition with white sharecroppers as well, keeping them in a cycle of debt and poverty.