Why did europeans use one-crop economies in their colonies?

In the time of the colonial era, European countries followed mercantilism.  This helped the production of agricultural products which could be exported to their motherland as raw materials for industries production there.  It also increased the importance of the capital market in the life of the colonial peoples.  As a result, larger numbers of land was shifted from growing food crops to growing “cash crops,”.

what are local authorities doing to fix the problem

explanation:

what are local authorities doing to fix the problem

the answer is mass marketing.